Africa Surveyors Magazine

Africa SurveyorsMarch-April 2025 Volume 7 issue no. 38In this issue......The Benefits Hyperspectral Imaging in Remote Sensing Applications....Why Precision and Accuracy are Important in Drone Mapping....Economic Benefits of Advanced Air Monitoring Technologies for Mines in Africa....3D Mobile Mapping Solutions for Public SafetyWhy You Need to Hire a Professional Land SurveyorFluxgate Sensors Remain a Preferred Choice for GeophysicistsGIS Technology in Land SurveyingThe Future of Africa’s Land lies in Strong GIS Usepg 20 pg 22 pg 12

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www.africasurveyorsonline.com March-April issue l 2025 3ContentsCurrent IssueIn this issue, we look at How GIS Technology is Transforming Land Surveying Practices in Africa and much more...enjoy the issue!The Editor accepts letter and manuscripts for publication from readers all over the world. Include your name and address as a sign of good faith although you may request your name to be withheld from publication. We can reserve the right to edit any material submitted. Send your letters to: [email protected]:Nailex Africa Publishing Ltd makes every effort to ensure the accuracy of the contents of its publications, but no warranty is made to such accuracy and no responsibility will be borne by the publisher for the consequences of actions based on information so published. Further, opinions expressed on interviews are not necessarily shared by Nailex Africa Publishing Ltd.Contact us:Tel: +254 113 194 740Email: [email protected]: https://africasurveyorsonline.comNAPL.......................................................................................................................................................IFCC.R Kenn.edy.........................................................................................................................................IBCEvoLogics............................................................................................................................................OBCSaab.....................................................................................................................................................pg 37MacArtney.........................................................................................................................................pg 38REGULARSNews Briefs 4Events 10Innovation 12Opinion 6Safety Tips 36Director Augustine M. Rang’ondiSenior Editor & Marketing LeadDorcas Kang’erehaWritersDavid LawrenceIrene JosephClaudia MangiSales ExecutivesEast AfricaStephen MashaFrancis MwambaMariam KombeFlorence NdewaSouth AfricaPaul NyakeriLisa BrownNigeriaBenadine MethuObadiah KanjaPublished andDesigned By:Josem Trust House, 3rd Floor, Bunyala Road, Upper Hill.P.O. Box 52248-00100, Nairobi, Kenya.ADVERTISER’S INDEXCOVER STORYGIS Technology: How GIS Technology is Transforming Land Surveying PracticesFEATURESOpinion: How geomatics, Legal Puralism, and History Shape SA’s Land Justice FutureSurveyors: The Role of African Surveyors in Urban DevelopmentProfessional Land Surveyor: How Residential Property Owners Can Benefit from Hiring a Professional Land SurveyorDrones: Why Precision and Accuracy are Important in Drone Mapping3D Mobile Mapping: Enhancing Public Safety Through 3D Mobile Mapping Solutions Hydrographic Surveyor: Key Considerations When Selecting a Geodesy Training Program for a Hydrographic SurveyorMining: The Economic Benefits of Investing in Advanced Air Monitoring Technologies for Mines in Africa22341810CONTENTS1226

4 March-April issue l 2025 www.africasurveyorsonline.comNEWS BRIEFSRear Admiral Ayodeji Olugbode, Hydrographer of the Federation, stressed the vital need to elevate the economic and governance importance of hydrography across West Africa. Speaking at the World Hydrography Day celebration in Abuja, Nigeria, he highlighted the event’s theme, “Seabed Mapping, Enabling Ocean Action,” and its alignment with the Seabed 2030 Initiative.This initiative aims to bolster regional cooperation through the West African Hydrographic Summit, facilitating joint surveys, data sharing, and presentations advocating for hydrography’s crucial role in navigation safety, climate resilience, environmental protection, and economic growth.Admiral Olugbode emphasized the planned showcases of innovative hydrographic technologies through exhibitions and demonstrations. He contrasted last year’s focus on hydrography’s role in maritime safety with this year’s broader aim: addressing regional shortcomings and aligning with global frameworks like the African Continental Free Trade Agreement and the UN Sustainable Development Goal 12 (“Life Below Water”). He underscored the ocean’s critical importance to human wellbeing and planetary health, stating, “The sea, accounting for 71% of the Earth’s surface, is vital for mankind’s sustenance.”The Admiral detailed the ambitious agenda of the West African Hydrographic Summit and the 2025 Hydrographic Geyser Generation, including an opening exhibition showcasing the proposed West African Regional Office and Training Center (hosted by Nigeria), and demonstrations of cutting-edge technologies such as unmanned vehicles and AI. Hydrography Making Waves in West Africa Tanzania’s New Step Towards Better Land ManagementTanzania is undertaking a significant national initiative to create a new, comprehensive map, directly addressing longstanding land disputes and bolstering border management. This project, launched alongside the 2023 revision of the 1995 National Land Policy, aims to revolutionize land planning and management, providing accurate data to prevent conflicts in urban and rural areas, as well as across international borders.President Suluhu announced the initiative, highlighting a $65 million investment from South Korea to upgrade surveying and mapping infrastructure. She emphasized the map’s crucial role in sustainable land use, efficient planning, and facilitating digital planning for multiple sectors. The project leverages the National Spatial Data Infrastructure (NSDI) for streamlined mapping and will benefit both government agencies and the private sector, which relies on accurate land data for operations.President Suluhu underscored the transformation of the Ministry of Lands from a dispute-resolution body to a central pillar of national development, echoing Julius Nyerere’s vision of land as the cornerstone of national prosperity. She cited a significant budget increase for the land sector, from Sh133.6 billion in 2023 to Sh171.4 billion for 2024/2025, demonstrating the government’s commitment to secure land ownership and effective planning.INTERGEO 2025INTERGEO 2025 (October 7-9, Frankfurt) brings more than 600 exhibitors to the EXPO with state-of-the-art geotechnics for smart cities, energy and mobility. While the CONFERENCE will deepen expert knowledge on geo-AI, BIM, drones and digital twins and inspire discussions.The INTERGEO Conference will take place over all three days of the event in Messe Frankfurt’s Portalhaus. With its 26-metre-high, glazed foyer, the Portalhaus as the entrance gate in the western part of the exhibition grounds will be a special memory for every guest.Nigerian Navy Hydrographic Survey Ship | Image: CourtesyOn March 17, 2025, President Samia Suluhu Hassan officially launched the digital issuance of land title deeds. The launch ceremony took place at the Jakaya Kikwete Convention Centre in Dodoma, looking on is the Lands, Housing and Human Settlements Development minister Deogratius Ndejembi. A photograph from the event shows President Hassan pressing a button to initiate the system. | Image: Tanzania State House

www.africasurveyorsonline.com March-April issue l 2025 5NEWS BRIEFSKenya’s Plan for Better Maps and Land ManagementKenya is modernizing its surveying, mapping, and land management systems to bolster national development. A key strategy is the creation of a modern geodetic reference system and a nationwide, large-scale mapping framework. This will improve infrastructure planning, affordable housing initiatives, and land resource management.The third Kenya Geodetic Reference System (KGRS) Strategy Development Workshop, held at the Kenya School of Monetary Studies, brought together stakeholders from the State Department for Lands and Physical Planning, the World Bank, and Frontier Consultants Limited. Director of Surveys Weldon Maritim highlighted the critical need for accurate geospatial data to drive Kenya’s development. Maritim noted that approximately 70% of Kenya, particularly the northern regions, lacks adequate mapping or relies on outdated data, a deficiency this initiative aims to address.Mr. Ibrahim Mwathane, a representative of the World Bank, emphasized the importance to take action. “This workshop must produce more than just recommendations—it must lead to real, measurable progress in Kenya’s geospatial capabilities,” he said.Professor Faith Karanja, a geospatial expert from Frontier Consultants Limited, also shared her thoughts, “For Kenya to become a regional leader in geospatial technology, our systems must align with international best practices. The KGRS rollout will be a gamechanger,” she said.IMAGE 2025The Society of Exploration Geophysicists (SEG), American Association of Petroleum Geologists (AAPG), and Society for Sedimentary Geology (SEPM) are pleased to announce the 5th annual International Meeting for Applied Geoscience and Energy (IMAGE ’25). This premier event, taking place August 25-28, 2025, at the George R. Brown Convention Center in Houston, Texas, convenes geoscientists, energy professionals, and industry leaders for a dynamic exchange of ideas and collaboration.IMAGE 2025 serves as a critical platform to:• Explore Emerging Opportunities: Explore the latest advancements in exploration, technology, and sustainability transforming the future of geoscience and energy.• Foster Networking: Build connections with a global network of industry peers to enhance expertise and drive innovation.• Shape the Future: Engage in discussions and collaborations to shape the future of geoscience and energy.Don’t miss this essential gathering! Start planning your participation now and seize the opportunity to push the boundaries of your field at IMAGE 2025.GEOxyz Opens First African Branch in NamibiaGEOxyz, a global leader in data services, has announced the opening of its first African branch in Walvis Bay, Namibia. This strategic move marks a significant milestone in the company’s international expansion, solidifying its commitment to serving the Southern African market with highquality, locally adapted solutions.Namibia’s central location, robust business environment, and growing demand for onshore and offshore infrastructure survey services made it the ideal location for GEOxyz’s regional headquarters. This base will enable efficient project support across Southern Africa.Leading the Namibian office is Jacques Vancayseele, a seasoned industry expert with over seven years of experience at GEOxyz and strong ties to both South Africa and Namibia. His leadership will bridge GEOxyz’s European heritage with its ambitious African expansion. Vancayseele expressed his enthusiasm, stating, “This region holds immense potential, and our dedicated local presence allows us to deliver tailored solutions that meet client needs while contributing to local growth and development.”The new office will initially operate collaboratively with GEOxyz’s European teams, with a longterm vision of becoming a fully independent, locally-led operation. GEOxyz is committed to hiring local talent, fostering partnerships with regional institutions, and investing in knowledge transfer to leverage its global expertise for the benefit of the Namibian team.GEOxyz Opens First African Branch in Namibia | Image: GeoxyzKenya Takes Bold Step Toward Modern Geospatial Infrastructure during the third Kenya Geodetic Reference System (KGRS) Strategy Development Workshop April 17, 2025 | Image: State Department for Lands and Physical Planning

6 March-April issue l 2025 www.africasurveyorsonline.comOPINIONProfessor Jenniffer Whittal’s personal and professional journey mirrors the evolving landscape of land justice in South Africa. Having first walked the University of Cape Town’s (UCT) upper campus as an undergraduate 35 years ago, the university has been a constant thread through her life – as a student, researcher, teacher, and mother.But her inaugural lecture on 3 June was not just an academic exercise but a deeply personal reflection on how land boundaries – both literal and conceptual – shape identity, power, and opportunity. Titled “Beyond Boundaries” and attracting a large audience of students, academics and members of the public, the lecture wove together centuries of colonial legacy, cuttingedge technology, and African legal pluralism to illuminate the complex realities that continue to define land administration and social equity today.“We must ask ourselves whether our systems serve the people they are meant to serve,” she said.Using a rich tapestry of historical documents, geographic information systems (GIS), and fieldwork, Professor Whittal traced the origins of Cape Town’s southern suburbs back to the 17th century. Remarkably, some of the original land boundaries, beacons, and survey marks laid down by early Dutch settlers like Pieter Potter remain intact today. One such beacon, known as “Beacon F”, rests at the corner of a wall and a tree, silently marking a boundary set over 350 years ago.“In South Africa, boundaries are not just physical features. They have shaped our physical and social landscapes.”These ancient markers and the meticulous hand-drawn maps they inspired reveal much more than property lines. They tell a story of exclusion, colonial conquest, and the erasure of indigenous land rights. “In South Africa, boundaries are not just physical features. They have shaped our physical and social landscapes,” Whittal noted.In 1659 for instance, settlers planted a hedge of wild almond trees as a formal racial boundary to separate themselves from indigenous Khoikhoi communities, denying them access to vital resources. Remnants of this hedge still exist, embedding colonial power into the physical landscape. “Some of the original boundaries and beacons still exist. But tracing them requires meticulous detective work through historical deeds, maps, and satellite data.”Through geomatics – the science of measuring and managing spatial data – Whittal and her students have reconstructed the geographic DNA of Cape Town’s colonial past. They used advanced techniques to georeference centuries-old maps, overlaying them with modern satellite imagery to reveal the persistence of early colonial farm boundaries in today’s urban layouts. “Geomatics can build a more just society. By acknowledging history and using technology ethically, we can support equitable land reform and spatial justice,” she revealed.One remarkable discovery was the Hen and Chickens rock formation near Wynberg Hill, believed to be South Africa’s oldest surviving pedestrian beacon, used by early surveyors as a vantage point to lay out farms. Despite efforts to recognise and protect this heritage site, a recent provincial heritage application was inexplicably denied, prompting digital preservation initiatives through 3D laser scanning.The lecture also examined contemporary challenges, such as defining the high-water mark – the legally contested boundary between public coastal land and private beachfront property. Here, geomatics plays a vital role in settling disputes and ensuring equitable access to natural resources amid environmental change.Legal pluralism a framework for justiceCentral to Whittal’s lecture was the concept of legal pluralism – the coexistence of multiple legal systems within one country. South By Myolisi GopheHow geomatics, legal pluralism, and history shape SA’s land justice futureThis insight cautions against imposing rigid, Western-centric reforms on land administration. Instead, it calls for interdisciplinary collaboration between geomatics experts, social scientists, and legal anthropologists to develop solutions that respect local realities and empower marginalised communities

www.africasurveyorsonline.com March-April issue l 2025 7OPINIONAfrica’s Constitution uniquely recognises African customary law as equal in status to the state legal system. This legal pluralism challenges the dominance of Western legal frameworks that traditionally view land rights through an individualistic, static lens.By contrast, many African communities understand land ownership as a living, intergenerational stewardship, embedded in family lineages and collective responsibility. These customary systems often defy neat categorisation within state legal frameworks, which tend to emphasise discrete legal ownership rather than fluid, social relationships with the land.“Alternative normative legal systems, such as customary, indigenous, informal, and religious law, continue to thrive across the continent. They are resilient, adaptive, and deeply embedded in social practices and institutions.”The lecture illustrated a continuum of legal pluralism, from weak forms where alternative legal systems are only recognised when validated by the state, to deep forms, where such systems exist and operate independently. “In truly plural legal contexts, it is a fallacy to claim these systems exist in parallel. Their relationships are complex, overlapping, and often nested,” she noted. Understanding how people choose between legal systems in different scenarios is key to designing more inclusive and functional land administration interventions.“We are called to embrace diversity rather than constrain it. legal pluralism offers a pathway to reimagine and reshape land governance systems.”This perspective is not only academically rigorous but also politically urgent, especially in efforts to decolonise land administration and broaden access to land rights for the poor and marginalised. “There is great potential in the margins. We are called to embrace diversity rather than constrain it. Legal pluralism offers a pathway to reimagine and reshape land governance systems.”This insight cautions against imposing rigid, Western-centric reforms on land administration. Instead, it calls for interdisciplinary collaboration between geomatics experts, social scientists, and legal anthropologists to develop solutions that respect local realities and empower marginalised communities.“We must move beyond the assumption that the state is the sole creator and enforcer of law. In contexts of limited state capacity, or even state failure, customary systems often provide more effective governance,” Whittal said.Investing in Africa’s futureWhittal’s career exemplifies commitment to building capacity and leadership in surveying and geomatics across Africa. She was the youngest female president of a local surveying institute in the 1990s and currently chairs the International Federation of Surveyors (FIG) Africa Regional Capacity Development Network.She mentors young African surveyors through annual programmes and serves on the FIG Foundation Board, helping secure scholarships and opportunities for emerging professionals from developing countries. Looking forward, she will chair the technical committee for the FIG Congress 2026, to be held in Cape Town – a major global event uniting experts across surveying, construction economics, and geoinformation sciences.Throughout her lecture, Whittal shared candid reflections on the challenges shaping her academic journey, including balancing early motherhood, heavy teaching loads, a cancer diagnosis, and a divorce. These personal experiences deepened her empathy and commitment to research that foregrounds people’s lived realities.“As we navigate the future, we must not only chart new boundaries. We must understand the maps we’ve inherited and commit to justice that transcends lines on a page.”Her co-authorship of a new, comprehensive textbook on South African cadastral systems, an overdue update since the last one written in 1973, is an essential resource for students, practitioners, and policy makers.The lecture concluded with a reminder that geomatics is not neutral. While it provides the tools to measure and map land, it must be wielded with intention to empower informal settlements, support equitable urban planning, and challenge exclusionary systems rooted in colonial history.“As we navigate the future, we must not only chart new boundaries. We must understand the maps we’ve inherited and commit to justice that transcends lines on a page. Land tenure is central to the Sustainable Development Goals. Understanding how laws and boundaries affect people’s lives is key to ensuring the reforms we make truly serve the people they’re meant to benefit.”Prof Jenniffer Whittal delivered her inaugural lecture on how colonial boundaries continue to define land administration and social equity. \\ Photo by: Lerato Maduna

8 March-April issue l 2025 www.africasurveyorsonline.comFEATUREThe rapid urbanization sweeping across Africa presents both unprecedented opportunities and significant challenges. Cities are expanding at an astonishing rate, and the need for accurate, reliable, and sustainable spatial data has become nonnegotiable. This is where African surveyors step into the spotlight, playing a pivotal role in shaping the future of urban development across the continent. Their contributions extend far beyond simply mapping land; they are integral to ensuring equitable, efficient, and resilient urban environments.Historically, surveying in Africa has faced numerous obstacles. Colonial legacies often left behind fragmented land tenure systems and inadequate spatial data infrastructure. Limited access to technology and training further hampered progress. However, in recent decades, a significant transformation has been underway. A new generation of African surveyors, equipped with modern technology and a deep understanding of local contexts is emerging, actively contributing to sustainable urban development. In different African countries, surveyors are increasingly recognized as key players in shaping the future of their cities, contributing far beyond the simple plotting of boundaries. Their expertise is essential across numerous facets of urban planning and construction, which includes:Land Administration and Tenure SecurityOne of the most critical roles of African surveyors is in land administration. Secure land tenure is fundamental to economic development, fostering investment and reducing conflict. Surveyors play a pivotal role in establishing clear land boundaries, registering property rights, and creating accurate land information systems (LIS). This is especially crucial in rapidly growing urban areas where informal settlements often lack formal land titles, making residents vulnerable to displacement and exploitation. However, though the provision of reliable cadastral surveys and supporting the development of robust LIS, African surveyors contribute directly to improving livelihoods and promoting social stability. Their work is not simply technical; it is fundamentally about social justice and empowerment to every land owner. Infrastructure DevelopmentThe rapid expansion of the African cities demands significant investment in infrastructure: roads, water and sanitation systems, electricity grids, and housing. Therefore, accurate surveying is fundamental to the successful planning and implementation of these projects. Surveyors provide the baseline data needed for design, construction, and monitoring, ensuring that infrastructure is built efficiently and effectively. They utilize various technologies, including GPS, LiDAR, and drones, to create detailed threedimensional models of the urban landscape, which are essential for optimizing infrastructure placement and minimizing environmental impact. For example, in the design of transportation networks, accurate surveying is crucial for route planning, minimizing land acquisition costs, and mitigating disruption to existing communities. Similarly, in water resource management, surveying helps optimize the location of dams, pipelines, and treatment plants.Urban Planning and DesignCurrently in Africa, surveyors are increasingly involved in the strategic planning and design of cities. They contribute essential data for urban growth management, identifying areas suitable for development while protecting environmentally sensitive zones. As majority are now utilizing the use of GIS (Geographic Information Systems) and other spatial analysis tools, surveyors are creating detailed maps and models that inform decisions on zoning, land use allocation, and urban density. By Dorcas Kang’erehaThe Role of African Surveyors in Urban Development8 March-April issue l 2025 www.africasurveyorsonline.com

www.africasurveyorsonline.com March-April issue l 2025 9SURVEYORS IN URBAN DEVELOPMENTThis contributes to the development of sustainable and resilient cities that can accommodate growing populations while minimizing environmental degradation. Their expertise in spatial analysis sanction for effective modeling of various urban planning scenarios, enabling informed decision-making regarding infrastructure development, transportation systems, and land use patterns.Disaster Risk Reduction and Environmental ManagementAfrican cities are particularly vulnerable to various natural hazards, including floods, droughts and earthquakes. Surveyors play a critical role in assessing risk, mapping vulnerable areas, and developing mitigation strategies. Through detailed topographical surveys, hydrological modelling and the use of remote sensing techniques, can aid in identifying areas prone to landslides or flooding, informing the development of early warning systems and landuse planning that minimizes risk to communities. Furthermore, their work in environmental monitoring and assessment contributes to sustainable urban development by supporting initiatives to protect biodiversity and manage natural resources. This includes mapping ecosystems, monitoring deforestation, and assessing the impact of urbanization on the environment.Technological Advancements and Capacity BuildingThe surveying profession in Africa is undergoing a significant transformation, driven by technological advancements. The adoption of GPS, LiDAR, drones, and GIS is enhancing efficiency, accuracy and the breadth of services offered by surveyors. However, this requires continuous capacity building and training to ensure that surveyors in Africa are equipped with the skills and knowledge to effectively utilize these new technologies. Challenges and OpportunitiesDespite the critical role they play, surveyors in Africa face enduring challenges. These include:Limited resources and funding: Lack of adequate funding for equipment, training, and infrastructure hampers the effective implementation of modern surveying techniques.Lack of standardization and integration: Inconsistent data standards and a lack of integration between different spatial data sources impede the creation of comprehensive and reliable spatial information systems.Skills gaps: While the adoption of geospatial technologies is increasing, still remains a significant gap between the availability of these technologies and their effective implementation on the ground. The rapid advancement of technology requires ongoing training and upskilling to ensure surveyors are equipped with the latest knowledge and expertise.Professional Recognition: The need for greater recognition of the profession and its contribution to national development is crucial.Investment in the Future of African Urban SpacesSurveyors in Africa are indispensable players in the ongoing transformation of Africa’s urban landscapes. Their expertise forms the cornerstone of sustainable urban development, ensuring that cities are built not just for today, but for generations to come. International collaborations and knowledge-sharing initiatives can also contribute to strengthening the surveying profession across the continent. Their work is fundamental to ensuring equitable access to land, efficient infrastructure development, and resilient urban environments. As they courageously address the challenges encountered and harnessing the opportunities before them, African surveyors will continue to make significant contributions to the growth and prosperity of cities across the continent. Their expertise is a great hope to social justice, economic progress, and environmental sustainability. Additionally, collaboration between surveyors, urban planners, engineers and other stakeholders is essential to achieve the desired sustainable and equitable urban development. Investing in surveyor’s capabilities is an investment in the future of African urban spaces.An illustration of an African surveyorwww.africasurveyorsonline.com March-April issue l 2025 9

COVER STORYLand administration and management, is a major problem particularly in the vast and diverse landscapes of Africa. Secure land tenure, accurate land records, and efficient resource management are crucial for economic development, social stability, and environmental protection. Ordinary land surveying methods, often laborious, timeconsuming, and susceptible to errors, are proving increasingly inadequate to meet these demands. However, the integration of Geographic Information System (GIS) technology is revolutionizing land surveying practices across the continent, offering unprecedented opportunities for improved accuracy, efficiency, and accessibility. Moreover, the burgeoning field of GIS technology is rapidly taking shape in numerous sectors globally, and its impact on land surveying practices in Africa, is particularly profound and multifaceted. Surv. Eric Nyadimo, Managing Director and ISK President cites that, “GIS provides a central Repository for data used for analysis in surveying, planning, construction and management. Land surveyors provide data for the GIS and in turn, use the data to provide more accurate, less expensive surveys. With accelerating advancements in GIS technology, surveyors can offer more services.”Ordinary land surveying has long relied on labor-intensive methods, often employing rudimentary tools and techniques. This approach is slow, prone to errors, and struggles to keep pace with the increasing need for detailed and up-to-date land information. Furthermore, the lack of robust infrastructure and technological resources in many parts of the continent, further exacerbates these challenges. Data compilation and management are often fragmented, making it difficult to create a comprehensive and consistent land record system. This lack of clarity contributes to land disputes, hindering investment and economic growth.GIS technology offers a powerful solution to these problems. Through integration of various data sources, including satellite imagery, aerial photography, GPS data, and cadastral maps, GIS provides a comprehensive platform for creating and managing spatial data. This allows surveyors to perform tasks more efficiently and accurately. Let’s discuss in-depth on how key applications of GIS are transforming land surveying. In Africa, the technology manifests in several crucial ways, which includes:1. Enhanced Mapping and Data Collection: GIS facilitates the creation of highly detailed and accurate maps, crucial for numerous landrelated applications. As Nyadimo endorses, “Using Mobile GIS tools and Handheld GPS devices, surveyors can collect, upload and access data directly from the field. This real-time data integration means quicker decision-making and reduces redundancy.” This is particularly beneficial in remote or inaccessible regions where ordinary methods are impractical or impossible. 2. Improved Cadastral Mapping and Land Registration: Cadastral mapping, the detailed mapping of land parcels for registration purposes, is essential for secure land tenure. GIS plays a vital role in creating and updating cadastral maps, providing a clear and unambiguous representation of land ownership. Integrating cadastral data with other spatial datasets, The future of Africa’s land lies in strong GIS UseHow GIS Technology is Transforming Land Surveying Practices10 March-April issue l 2025 www.africasurveyorsonline.comBy Dorcas Kang’ereha

www.africasurveyorsonline.com March-April issue l 2025 11such as population density, soil type, and infrastructure, enables a more comprehensive understanding of land use and facilitates informed decision-making related to land allocation and development. This improved accuracy reduces land disputes and enhances land tenure security, fostering investment and economic growth.3. Efficient Land Use Planning and Management: GIS provides a powerful tool for land use planning and management. Integrating data on land ownership, environmental conditions, infrastructure, and socio-economic factors, GIS enables planners to create realistic and sustainable land use plans. This allows for better allocation of resources, minimizing environmental impact and promoting equitable development. Additionally, GIS-based modeling and simulation tools can also assess the impact of different development scenarios, informing crucial policy decisions. For example, analyzing the potential impact of urbanization on agricultural land or understanding the vulnerability of communities to natural disasters.4. Disaster Response and Management: GIS is at the forefront championing the crucial role in disaster response and management in Africa, which is highly vulnerable to natural hazards such as floods, droughts, and earthquakes. The technology is used to map affected areas, assess damage, and plan relief efforts. Whereas, real-time data integration enables quick response and effective resource allocation during emergencies. Post-disaster assessment using GIS also helps inform reconstruction and rehabilitation efforts, promoting resilient development.5. Digital Land Administration and Data Sharing: GIS facilitates collaboration among various stakeholders involved in land management, this includes the government agencies, private companies, and local communities. Sharing his opinion on collaboration and data sharing, Nyadimo states that, “GIS is used in Land Information Management Systems (LIMS) where land survey data is stored, managed and analyzed easily and centrally.” Certainly, a centralized GIS platform allows for streamlined data sharing and collaboration, preventing data duplication and ensuring consistency. This is particularly important in addressing transboundary land issues and promoting regional cooperation. Open-source GIS software and initiatives further strengthen these collaborative efforts by making the technology more accessible and affordable.6. Conflict Resolution and Tenure Security: Land disputes are a major source of conflict across Africa. GIS technology aids in resolving these disputes by providing irrefutable evidence of land ownership and boundaries. These advanced capabilities create accurate and easily accessible land records, contributing to increased tenure security, empowering communities and fostering investment.7. Integration with other Technologies: “GIS integrates with GNSS and Remote Sensing technology to provide land surveyors with accurate geospatial data. Tools like drones (UAVs) and LiDAR capture high resolution topographic data, especially useful in fast data capture in the case of UAV’s or high precision data in the case of LiDAR,” highlights Nyadimo. This integration enables the creation of comprehensive and up-to-date spatial data for various applications, including Surv. Eric Nyadimo, President Institution of Surveyors of Kenya (ISK) and the Managing Director – Oakar Services LtdGIS IN LAND SURVEYINGmonitoring deforestation, assessing natural resources, and managing infrastructure projects.The Future of Africa’s Land Lies in Strong GIS UseFor decades, land surveying in many parts of Africa for instance Kenya, relied heavily on manual methods, including chain surveying, compass traversing, and plane table surveying. These techniques are timeconsuming, prone to errors, and often inadequate for the complexities of the modern land administration. Data management was typically paper-based, making it difficult to access, share, and update information efficiently. This lack of accurate and accessible land information contributed to land disputes, tenure insecurity, and hindered investment in infrastructure development as well as agricultural productivity.Nonetheless, addressing these challenges requires collaborative efforts between governments, international organizations, private sector players, and the academic institutions. Practically, investing in infrastructure development, capacity building, and affordable technology solutions are the crucial steps towards realizing the full potential of GIS in transforming land surveying practices and fostering sustainable land management in Africa. In his concluding remarks, Nyadimo give emphasis to how, “GIS is revolutionizing land surveying by enabling faster, digital, transparent and efficient land management. Its integration into Land Administration, Urban planning and Environmental monitoring is reshaping how governments, businesses and communities interact with land surveying data.” The future of land administration in the Africa landscapes hinges on embracing and effectively utilizing the power of GIS technology. GIS holds the key to better land surveying and lasting management in Africa.

12 March-April issue l 2025 www.africasurveyorsonline.comFEATUREWhy Precision and Accuracy are Important in Drone MappingDrone mapping, also known as UAV (Unmanned Aerial Vehicle) mapping, has rapidly evolved from a niche technology to a widely adopted tool across numerous industries. However, the true value of drone mapping hinges critically on the precision and accuracy of the data collected. Inaccurate data can lead to flawed decisions, costly rework, and even safety hazards. Let’s discuss the critical importance of precision and accuracy in drone mapping and the factors that contribute to achieving optimal results, implementing best practices to ensure high-quality results, for successful drone mapping projects.But first, precision and accuracy in the context of Drone Mapping. These concepts are often used interchangeably, but they represent distinct aspects of data quality:Accuracy: Refers to how close the mapped data is to the real-world coordinates. A highly accurate map, correctly represents the actual location and dimensions of features on the ground. Accuracy is influenced by factors like GPS accuracy, ground control points (GCPs), and the quality of the processing software.Precision: Describes the level of detail and consistency in the measurements. A precise map shows consistent and repeatable measurements, even if those measurements are slightly offset from their true locations. Precision is affected by factors such as camera resolution, overlap between images, and the flight planning strategy.Both accuracy and precision are essential for reliable drone mapping. A map can be precise but inaccurate (all measurements are consistently wrong) or accurate but imprecise (measurements are scattered around the true value). Ideally, a successful drone mapping project delivers both high accuracy and high precision.Factors Affecting Precision and Accuracy in Drone MappingSeveral factors contribute to the precision and accuracy of drone mapping data. Understanding and mitigating these factors is key to achieving high-quality results:GPS Accuracy: The accuracy of the drone’s GPS receiver directly impacts the overall accuracy of the map. Factors like atmospheric interference, multipath errors (signals reflecting off surfaces), and the quality of the GPS receiver itself can all affect the GPS position. Using RTK (Real-Time Kinematic) or PPK (Post-Processed Kinematic) GPS significantly improves accuracy by correcting for these errors.Sensor Quality: The camera or sensor onboard the drone is the primary data acquisition instrument. High-resolution sensors with low distortion and accurate geolocation capabilities are essential. The type of sensor (RGB, multispectral, thermal) also dictates the type of data collected and the level of accuracy achievable for specific applications.Ground Control Points (GCPs): GCPs are physical points on the ground whose precise coordinates are By Dorcas Kang’ereha12 March-April issue l 2025 www.africasurveyorsonline.com

www.africasurveyorsonline.com March-April issue l 2025 13DRONE MAPPINGknown. By including GCPs in the imagery, the software can accurately georeferenced the images, improving the accuracy of the final map. The number and distribution of GCPs are crucial; more GCPs, strategically placed, generally lead to higher accuracy.Image Overlap: Sufficient overlap between consecutive images is crucial for successful photogrammetry, the process of generating 3D models and maps from overlapping images. Overlapping images provide the software with multiple perspectives of the same features, allowing it to generate more accurate and detailed models. Typical overlap ranges from 60-80% sidelap and 70-80% frontlap.Camera Calibration and Resolution: The camera’s internal parameters (focal length, principal point, etc.) must be accurately calibrated. The higher the camera resolution, the more detail captured, leading to improved precision. Using highquality calibrated cameras is crucial for achieving high-quality results.Flight Planning and Execution: Careful flight planning is essential. Consistent altitude, speed, and overlap are vital for precise data acquisition. Factors like wind conditions and atmospheric stability can affect the flight and impacting data quality.Image Processing Software: The choice of photogrammetry software significantly impacts the final output. Different software packages have varying capabilities and algorithms for processing images, affecting the accuracy and precision of the resulting map. Selecting a reputable and robust software package is crucial.Environmental Conditions: Weather conditions like wind, rain and fog can significantly affect the quality surveying and boundary disputes.Best Practices for Ensuring Precision and AccuracyTo ensure high-precision and highaccuracy drone mapping, several best practices should be followed:Employ RTK or PPK GPS: Leverage RTK or PPK GPS for accurate georeferencing.Utilize Sufficient GCPs: Strategically place a sufficient number of GCPs, appropriately distributed throughout the survey area.Maintain Consistent Flight Parameters: Ensure consistent altitude, speed, and overlap during the flight.Use High-Quality Equipment: Invest in calibrated cameras and reliable drones.Process Images with Robust Software: Select a proven and reliable photogrammetry software package.Conduct Thorough Quality Control: Implement rigorous quality control checks at each stage of the process.Make Informed Decisions Across Diverse ApplicationThe precision and accuracy of drone mapping data are paramount. Nonetheless, understanding the factors that can affect data quality and implementing best practices, professionals can leverage the full potential of drone mapping to obtain reliable, actionable information that drives informed decisions across a diverse range of applications. The investment in high-quality equipment, meticulous planning, and robust post-processing techniques is crucial for ensuring the integrity and value of drone mapping projects. To add, the pursuit of high precision and accuracy is not merely a technical exercise but a crucial ethical and practical consideration in ensuring the responsible and effective use of this transformative technology.of the captured imagery and the stability of the drone’s flight, and simultaneously impacting the precision and accuracy of the final data results. Additionally, atmospheric effects like temperature, pressure, and humidity can distort the captured imagery and affect GPS accuracy. These atmospheric conditions need to be considered during post-processing to improve the accuracy of the final product.Post-Processing Techniques: Sophisticated software is crucial for processing the raw drone imagery. Photogrammetry software utilizes algorithms to stitch together overlapping images, generate 3D models, and create orthomosaics (georeferenced maps). Careful selection of appropriate processing parameters and quality control measures are essential to ensure accurate and reliable results.Consequences of Inaccurate Drone Mapping DataThe consequences of inaccurate drone mapping data can be significant and far-reaching:Costly Rework: Inaccurate data can lead to design flaws in construction projects, necessitating costly rework and delays. In agriculture, incorrect measurements may lead to inefficient fertilizer application or planting strategies.Safety Hazards: Inaccurate maps used in infrastructure inspection or emergency response can lead to misjudgments and potentially dangerous situations.Inefficient Resource Allocation: Inaccurate data can lead to inefficiencies in resource management, whether in farming, forestry, or urban planning.Legal and Regulatory Issues: Inaccurate surveys can have legal implications, particularly in land www.africasurveyorsonline.com March-April issue l 2025 13

14 March-April issue l 2025 www.africasurveyorsonline.comFEATUREIn the realm of public safety, accurate and timely information is paramount. First responders, law enforcement, and emergency management teams rely on situational awareness to effectively respond to incidents, mitigate risks, and protect communities. In Africa, major regions of the continent faces unique challenges in ensuring public safety, from sprawling urban areas with inadequate infrastructure to vast rural landscapes with limited accessibility. Traditional methods of data collection, such as manual surveys and aerial photography, are time-consuming, resourceintensive, and often lack the level of details required for optimal decision-making. This is where 3D mobile mapping solutions offer a transformative potential, providing a powerful tool to enhance public safety initiatives across various sectors.“3D Mobile Mapping stands out as a game-changer in the digital age of innovation in mapping technology,” Says Surv. Eric Nyadimo, Managing Director – Oakar Services Ltd and the ISK President. “This technology enables collection of detailed spatial data in a fast, efficient and accurate manner. 3D Mobile Mapping can significantly enhance public safety,” he adds.What is 3D Mobile Mapping? 3D mobile mapping involves the use of vehicle-mounted systems equipped with a combination of sensors, including LiDAR (Light Detection and Ranging), cameras, and GPS/IMU (Inertial Measurement Unit) systems. These systems rapidly capture highly accurate and detailed 3D spatial data of the surrounding environment as the vehicle moves. This data is then processed to create precise 3D models, point clouds, and orthorectified imagery, providing a comprehensive and realistic representation of the area surveyed.Applications of 3D Mobile Mapping in Public SafetyThe benefits of 3D mobile mapping for public safety are multifaceted, impacting various aspects of emergency response, law enforcement, and urban planning. Here are some key applications:• Enhanced Situational Awareness: 3D models generated from mobile mapping provide first responders with a virtual walkthrough of an incident site before they even arrive. According to Nyadimo, “3D Mobile Mapping can be used for Real-time Situational Awareness such that first responders can use the data to navigate to disaster zones in a timely manner. High resolution 3D models can also help authorities simulate, optimize and execute evacuation plans in case of disasters.” This 3D application capability is crucial for minimizing risks to both responders and the public.• Accident Reconstruction and Crime Scene Documentation: Mobile mapping can rapidly and accurately document Enhancing Public Safety Through 3D Mobile Mapping Solutions

www.africasurveyorsonline.com March-April issue l 2025 15accident scenes and crime scenes, capturing every detail in 3D. “Law enforcement agencies can capture detailed 3D reconstruction of crime scenes for forensics and court evidence. By analyzing 3D data, law enforcement agencies can identify high-risk crime areas and apply predictive policing,” highlights Nyadimo.• Disaster Response and Damage Assessment: In the aftermath of natural disasters like earthquakes, floods, or hurricanes, mobile mapping can be deployed to quickly assess the extent of the damage. This information is crucial for coordinating rescue efforts, prioritizing resources, and planning recovery operations. The ability to quickly identify damaged infrastructure and assess the impact on critical services, significantly improves the efficiency of disaster response.• Infrastructure Management and Security: 3D mobile mapping is also valuable for infrastructure management. By creating detailed 3D models of roads, bridges, and other critical infrastructure, agencies can identify potential vulnerabilities and plan preventative maintenance. These models can also be used to enhance security by identifying potential threats and developing effective security protocols. • Emergency Planning and Simulation: The detailed 3D data collected through mobile mapping can be used to create realistic simulations of emergency scenarios. This allows emergency management teams to practice their response plans and identify areas for improvement. By simulating various scenarios, communities can better prepare for potential disasters and improve their overall resilience. • Public Health and Crowd Management: Nyadimo puts it plainly, “3D Mobile Mapping can be applied for crowd flow analysis, thereby optimizing layouts for large events, reducing stampede risks. In case of pandemics, governments can apply 3D Mobile Mapping to model high-density areas to enforce social distancing.”• Traffic Management and Road Safety: Road accidents remain a leading cause of death in many African countries. 3D mobile mapping is capable of improving road safety, by providing detailed data on road geometry, visibility, and signage. This data is used to identify dangerous intersections, blind spots, and areas requiring improved signage or traffic calming measures. Furthermore, the ability to model traffic flow and congestion patterns helps optimize traffic management systems, reducing congestion and improving response times for emergency vehicles. Benefits of Implementing 3D Mobile Mapping Beyond the specific applications, implementing 3D mobile mapping solutions offers several key benefits for public safety interventions:Improved Efficiency: Mobile mapping allows for rapid data acquisition, significantly reducing the time and resources required for traditional surveying methods. This allows agencies to focus on other critical tasks.Surv. Eric Nyadimo, President Institution of Surveyors of Kenya (ISK) and the Managing Director – Oakar Services Ltd3D MAPPING FOR PUBLIC SAFETYIncreased Accuracy: The high accuracy of 3D mobile mapping data ensures that decisions are based on reliable information, minimizing the risk of errors and improving the effectiveness of responses.Enhanced Safety: By providing first responders with a virtual walkthrough of an incident site, mobile mapping helps to minimize risks and improve safety for both responders and the public.Better Resource Allocation: Detailed 3D data allows agencies to allocate resources more effectively, ensuring that they are deployed to the areas where they are needed most.Improved Collaboration: 3D models and data can be easily shared between different agencies and stakeholders, facilitating better collaboration and coordination. Higher Speed and Sharper InsightsThe public safety is increasingly reliant on the rapid, and detailed data provided by 3D mobile mapping solutions. This technology represents a significant leap forward in enhancing public safety. Its role in safeguarding communities is become more vital, paving the way for quicker response times, improved situational awareness, and ultimately, increased public safety and security. The transformative potential of 3D mobile mapping for enhancing public safety is undeniable. However, addressing the associated challenges and fostering collaboration between agencies will ensure the widespread adoption and optimal utilization of this powerful tool. Nyadimo concludes urging that, “By leveraging 3D Mobile Mapping, Governments and other relevant organizations can proactively address safety risks, improve emergency response and eventually create safe environments.”

FEATUREElevate Your Surveying TasksA Professional’s Guide to Choosing the Right GNSS ReceiverAs a professional surveyor, choosing the right GNSS receiver is a critical decision that can significantly impact the accuracy and efficiency of your surveying projects. The right GNSS receiver can unlock access to higher accuracy, improved productivity, and expanded service offerings. Therefore, selecting the optimal GNSS receiver requires careful consideration of various factors. Let’s journey through a guide for professional surveyors on the critical aspects to evaluate when making this crucial investment.1. Accuracy and Precision: The Cornerstone of SurveyingAccuracy remains the bedrock of any surveying operation. The GNSS receiver’s ability to provide precise and reliable positioning data is nonnegotiable. The required accuracy levels for each application will significantly influence your GNSS receiver selection. For instance, highprecision deformation monitoring demands a receiver with submillimeter accuracy, while general topographic surveys might tolerate centimeter-level accuracy.Consider these application-specific questions:Static Surveys: Do you require long observation periods for precise baseline measurements?RTK Surveys: Will you be performing real-time kinematic (RTK) surveys in challenging environments with obstructions?Network RTK: Do you plan to leverage network RTK services for wider coverage and enhanced reliability?GIS Data Collection: Will you be using the receiver for GIS data collection, requiring seamless integration with GIS software?Answering these questions will help you pinpoint the specific accuracy requirements and functional needs of your GNSS receiver.2. Frequency Bands and Satellite ConstellationsGNSS receivers utilize signals transmitted from various satellite constellations, including GPS (United States), GLONASS (Russia), Galileo (European Union), and BeiDou (China). The more constellations a receiver can track, the greater its availability and reliability, especially in obstructed environments.Multi-Constellation Support: Opt for a receiver that supports multiple constellations to maximize satellite visibility and improve positional accuracy and reliability.Frequency Bands: Modern GNSS receivers typically utilize multiple frequency bands (e.g., L1, L2, L5) for each constellation. Multifrequency receivers offer enhanced accuracy and mitigate the effects of ionospheric delays, leading to more precise positioning, particularly over longer baselines.3. Receiver Type and IntegrationGNSS receivers are available in various form factors, each with its own advantages and disadvantages. Consider the following options:Integrated Receivers: These compact units combine the antenna, receiver, and data logger into a single, self-contained device. They are convenient and easy to use, making them suitable for a wide range of applications.Modular Receivers: These systems consist of separate antenna and receiver units, offering greater flexibility in antenna placement and system configuration. They are often preferred for high-precision applications where optimal antenna positioning is crucial.Smart Antennas: These integrated antenna and receiver units offer a balance of convenience and performance. They are typically smaller and lighter than modular systems, making them ideal for mobile applications.Software Integration: Ensure that the receiver is compatible with your existing surveying software and data processing workflows. Seamless integration will streamline your data collection and analysis processes, saving you time and effort.4. Real-Time Kinematic (RTK) Capabilities16 March-April issue l 2025 www.africasurveyorsonline.comBy Florence Ndewa

www.africasurveyorsonline.com March-April issue l 2025 17GNSS RECEIVERSRTK technology enables real-time, high-precision positioning with centimeter-level accuracy. If you plan to perform RTK surveys, consider the following factors:RTK Accuracy and Range: Evaluate the RTK accuracy and range specifications of the receiver. Consider the typical distances between your base station and rover during surveys.RTK Initialization Time: Look for a receiver with fast RTK initialization times, which will minimize downtime in the field.Base Station Options: Determine whether you will be using a dedicated base station, a network RTK service, or a combination of both. Ensure that the receiver is compatible with your chosen base station option.Network RTK Compatibility: If you plan to utilize network RTK services, verify that the receiver is certified and compatible with your chosen network provider.5. Data Logging and ConnectivityThe ability to efficiently log and transfer data is crucial for a streamlined workflow. Consider the following:Internal Memory: Ensure that the receiver has sufficient internal memory to store your survey data.Data Transfer Options: Look for a receiver with versatile data transfer options, such as USB, Bluetooth, and Wi-Fi.Data Format: Verify that the receiver supports common data formats, such as RINEX, for compatibility with various data processing software packages.Wireless Connectivity: Bluetooth and Wi-Fi connectivity can facilitate seamless data transfer to mobile devices and cloud storage services.6. Ruggedness and Environmental ConsiderationsSurveying often takes place in challenging environments. Choose a GNSS receiver that is built to withstand the rigors of field use.Environmental Protection: Look for a receiver with a high IP rating (Ingress Protection) for dust and water resistance.Operating Temperature Range: Ensure that the receiver can operate reliably within the temperature range of your typical survey locations.Shock and Vibration Resistance: Consider a receiver with robust shock and vibration resistance to withstand accidental drops and rough handling.7. Power ManagementLong battery life is essential for uninterrupted surveying operations.Battery Life: Evaluate the battery life specifications of the receiver and consider purchasing additional batteries or external power sources for extended surveys.Battery Type: Consider the battery type and availability of replacement batteries.Power Consumption: Look for a receiver with low power consumption to maximize battery life.8. Budget and Return on InvestmentGNSS receivers represent a significant investment. Carefully consider your budget and evaluate the return on investment (ROI) of different options.Initial Cost: Compare the initial cost of different receivers, including any necessary accessories or software.Maintenance and Repair Costs: Factor in potential maintenance and repair costs, as well as the availability of service and support.Increased Productivity: Consider the potential for increased productivity and efficiency with a more advanced receiver.Long-Term Value: Evaluate the long-term value and lifespan of the receiver.9. Brand Reputation and SupportChoose a GNSS receiver from a reputable manufacturer with a proven track record of quality and reliability.Customer Reviews: Read customer reviews and testimonials to get an idea of the real-world performance and reliability of the receiver.Technical Support: Ensure that the manufacturer offers comprehensive technical support and training resources.Warranty: Review the warranty terms and conditions to understand the coverage and duration of the warranty.10. Field Testing and EvaluationWhenever possible, conduct field tests and evaluations of different GNSS receivers before making a purchase.Demo Units: Request demo units from manufacturers or dealers to test the receiver in your specific surveying environment.Compare Performance: Compare the performance of different receivers head-to-head in terms of accuracy, reliability, and ease of use.Evaluate Workflow Integration: Assess how well the receiver integrates with your existing surveying software and workflows.Elevate Your Surveying Tasks Choosing the right GNSS receiver is a critical decision for any professional surveyor. As a surveyor, considering the factors outlined above, you can make informed decisions that will enhance your productivity, improve your tasks accuracy, and ultimately contribute to the success of your projects. Prioritize accuracy and reliability, but also consider the practical aspects of using the receiver in your specific work environment. Investing in the right GNSS receiver is an investment in the quality and reliability of your surveying services. Partnering with a reputable supplier who can provide expert advice and support throughout the selection and implementation process is also highly recommended.

18 March-April issue l 2025 www.africasurveyorsonline.comFEATUREWhy You Need to Hire a Professional Land SurveyorResidential properties are becoming more dynamic, marked by a rapid urbanization and a growing need for secure land ownership. To ensure that your land is accurately measured and demarcated, you will need the services of a professional land surveyor. Hiring a professional land surveyor will provide you with numerous benefits that will protect your investment and ensure the smooth running of any construction or development plans you may have. Here are some of the key advantages of working with a professional land surveyor:1. Accurate Property Boundaries: A professional land surveyor using advanced surveying techniques and GPS technology will help you establish the exact boundaries of your property, ensuring that you know precisely where your land ends and your neighbor’s begins. This information is crucial particularly when planning for construction, landscaping, or development projects, as it will help you avoid encroaching on your neighbor’s property or violating local zoning regulations. Additionally, a surveyor’s expertise is vital in interpreting existing title deeds, identifying discrepancies, and resolving conflicts amicably or providing strong evidence for legal action if necessary. This is especially critical in areas with rapidly changing land use and informal settlements where documentation might be incomplete or contested.2. Avoiding Disputes: By establishing clear property boundaries, you can prevent potential disputes with your neighbors. If a dispute does arise, having a professional land survey on record can help resolve the issue quickly and fairly.3. Identifying Easements and Encumbrances: A professional land surveyor can identify any easements or encumbrances that may affect your property. Easements grant others the right to use your land for specific purposes, such as access to a public road or utility lines. Encumbrances are any claims or limitations on the property, such as liens or restrictions on use. Knowing about these issues beforehand can help you avoid costly surprises and make informed decisions about your property.4. Zoning Compliance: Professional land surveyors are familiar with local zoning regulations and can help ensure that your property complies with these rules. This is especially important if you are planning to build or expand structures on your land. Failing to adhere to zoning regulations can result in fines, penalties, or even a forced demolition of non-compliant structures.5. Improved Development Plans: Accurate land surveys are essential for creating detailed and effective development plans. By providing By Stephen MashaHow Residential Property Owners Can Benefit from Hiring a Professional Land Surveyor

www.africasurveyorsonline.com March-April issue l 2025 19LAND SURVEYINGproperty boundaries, professional land surveyors play a critical role in broader infrastructure development. Accurate surveys are fundamental to planning roads, utilities, and other essential services. Land surveyors provide reliable data that ensures efficient and effective infrastructure development, benefiting the entire community and enhancing the value of surrounding properties. This is particularly important in rapidly growing urban areas in Africa where infrastructure development often lags behind population growth. 12. Peace of Mind: Perhaps the most significant benefit of hiring a professional land surveyor is the peace of mind that comes from knowing your property boundaries and regulations are well-understood and documented. With a professional land survey in hand, you can focus on enjoying your property and planning for its future confidently, knowing that you have all the information you need to make informed decisions.Beyond Placing Stakes in the GroundIt is crucial to hire a qualified and experienced land surveyor. Ensure that the surveyor is licensed and registered with the relevant professional body in your country. Check their credentials, experience, insurance coverage, and client testimonials before engaging their services. A reputable surveyor will provide clear and concise reports, adhering to professional standards and ethical practices.A professional land surveyor is a highly trained specialist responsible for accurately measuring and mapping land boundaries. However, their work goes far beyond simply placing stakes in the ground. They use sophisticated equipment and techniques, applying a deep understanding of surveying principles, legal frameworks, and local regulations to create precise and legally defensible land descriptions.precise information about the topography, boundaries, and features of your land, a professional land surveyor is capable of helping you design a plan that maximizes the potential of your property while minimizing costs and environmental impact.6. Reduced Risk of Legal Issues: By working with a professional land surveyor, you can reduce the risk of legal issues related to your property. Clear property boundaries, accurate land surveys, and compliance with zoning regulations can all help protect you from potential lawsuits or other legal challenges.7. Increased Property Value: A welldefined and legally documented property is significantly more valuable and marketable than one with unclear boundaries. Potential buyers are less likely to invest in a property with potential boundary issues. A professional survey report serves as irrefutable proof of ownership and precise property dimensions. This accurate documentation makes the property more attractive to potential buyers, increasing its market value and facilitating a smoother and quicker sale. In an increasingly competitive property market, having a clear title and precise boundaries is a considerable advantage.8. Secure Financing and Mortgage Approval: Securing a mortgage or other forms of financing for residential property requires proof of clear ownership and well-defined boundaries. Lending institutions demand a professional survey report as part of the application process to mitigate their risk. Providing a comprehensive survey plan improves the chances of loan approval, ensuring access to crucial capital for construction, renovation, or other property improvements. 9. Environmental Considerations: Professional land surveyors can help identify any environmentally sensitive areas on your property, such as wetlands or endangered species habitats. This information is essential for ensuring that your development plans comply with environmental regulations and minimize any negative impact on the local ecosystem.10. Efficient Use of Resources: Accurate land surveys can help you make efficient use of resources such as water, energy, and building materials. Understanding the topography and features of your land, you can design a development plan that optimizes the use of these resources, potentially saving you money and reducing your environmental footprint.11. Infrastructure Development and Planning: Beyond immediate

20 March-April issue l 2025 www.africasurveyorsonline.comFEATUREtypically from the visible to the nearinfrared (VNIR), shortwave infrared (SWIR), or even longer wavelengths. This detailed spectral information provides a unique “fingerprint” for each material, enabling the identification and quantification of earth surface features with remarkable accuracy.Benefits of using hyperspectral imaging in remote sensing applicationsThe benefits of using hyperspectral imaging in remote sensing applications are numerous and profound. Here are the significant Hyperspectral imaging captures information across a continuous spectrum, often spanning the visible, near-infrared (NIR), shortwave infrared (SWIR), and even thermal infrared regions. This fine spectral resolution allows for the identification and quantification of subtle spectral signatures that are unique to different materials and phenomena.Unlike multispectral sensors that capture a few broad bands of reflected or emitted energy, HSI sensors meticulously record data across a wide spectral range, The Benefits of Hyperspectral Imaging in Remote Sensing Applications

www.africasurveyorsonline.com March-April issue l 2025 21HYPERSPECTRAL IMAGING benefits of hyperspectral imaging in various remote sensing applications:1. Enhanced Material Identification and Classification: The core strength of HSI lies in its ability to differentiate materials based on their unique spectral signatures. Each substance, be it vegetation, minerals, soil, or man-made materials, interacts with light differently, causing unique spectral reflectance patterns. HSI can detect subtle variations in these patterns, allowing for precise identification of different types of vegetation (e.g., healthy versus stressed crops), mineral composition (e.g., identifying ore deposits), and even pollutants in water bodies. This detailed classification surpasses the capabilities of traditional multispectral sensors, which often struggle to distinguish materials with similar spectral reflectance in a limited number of bands.2. Improved Precision in Agriculture: In precision agriculture, HSI is transforming how farmers monitor crop health and manage resources. By analyzing the spectral signatures of plants, HSI can detect early signs of stress caused by diseases, nutrient deficiencies, or water scarcity. This allows for targeted interventions, such as applying fertilizers or pesticides only where needed, optimizing resource use, minimizing environmental impact, and ultimately boosting yields. HSI can also be used to monitor crop growth stages, estimate biomass, and guide harvesting operations, leading to increased efficiency and profitability.3. Advanced Environmental Monitoring: Environmental monitoring benefits significantly from HSI’s ability to detect subtle changes in ecosystems. HSI can be used to map deforestation rates, monitor the spread of invasive species, assess water quality, and detect pollution sources. For instance, it can identify different types of algae blooms in water bodies, providing crucial information for water management and public health. Similarly, HSI can detect the presence of specific pollutants in soil or air, allowing for early intervention and remediation efforts.4. Geological Mapping and Mineral Exploration: The exploration and extraction of mineral resources are greatly aided by HSI’s ability to identify and map different minerals and geological formations. HSI data can reveal subtle variations in mineral composition, indicating the presence of valuable ore deposits. This information can guide exploration efforts, reduce exploration costs, and improve the efficiency of mineral extraction. Furthermore, HSI can be used to map geological structures and assess geological hazards, providing crucial information for infrastructure development and risk management.5. Urban Planning and Infrastructure Management: HSI can contribute significantly to urban planning by providing detailed information about the urban landscape. It can be used to monitor urban sprawl, assess the condition of urban infrastructure (e.g., roads and buildings), and identify areas prone to flooding or landslides. HSI can also be used to monitor air quality in urban areas, providing valuable data for urban environmental management.6. Defense and Security Applications: HSI finds applications in defense and security through its ability to detect camouflaged objects, identify targets, and monitor environmental conditions. It can be used for surveillance, target identification, and reconnaissance, playing a crucial role in military operations and national security.Challenges and Future DirectionsDespite its significant advantages, HSI faces several challenges. The large volume of data generated by HSI requires significant computational resources for processing and analysis. The high cost of HSI sensors and the specialized expertise needed for data interpretation also pose limitations.However, the ongoing advancements in sensor technology, data processing algorithms, and cloud computing are mitigating these challenges. Additionally, the development of more compact and affordable HSI sensors, coupled with improved data analysis techniques, is making HSI more accessible and widely applicable. Future research focuses on improving the speed and efficiency of HSI data processing, developing new algorithms for data analysis, and expanding the applications of HSI to new domains.Nonetheless, hyperspectral imaging is revolutionizing remote sensing applications, offering unprecedented detail and accuracy in the identification and quantification of Earth’s surface features. Its ability to provide comprehensive spectral information has far-reaching implications across numerous fields, from agriculture and environmental monitoring to urban planning and defense. As technology continues to advance, hyperspectral imaging will undoubtedly play an even greater role in our understanding and management of the planet.Hyperspectral imaging is transforming remote sensing applications by providing unparalleled precision and detail in identifying and analyzing Earth’s surface features. Its capacity to deliver detailed spectral data holds significant potential across various domains, including agriculture, environmental monitoring, urban planning, and defense. With ongoing advancements in technology, hyperspectral imaging is set to play an increasingly significant role in enhancing our understanding and stewardship of the planet.

22 March-April issue l 2025 www.africasurveyorsonline.comFEATUREBreathing EasierAfrica’s mining sector is a cornerstone of its economy, contributing significantly to GDP, employment, and foreign investment. However, the industry faces significant challenges, not least among them the inherent risks associated with underground and surface mining operations. Poor air quality in mines, is also a pervasive problem across the continent, posing a substantial threat to worker health, safety, and ultimately, profitability.Investing in advanced air monitoring technologies offers a powerful strategy to mitigate these risks, ultimately delivering significant economic benefits beyond the immediate cost of implementation. Here are the economic advantages of adopting sophisticated air monitoring systems in mine operations in Africa.Reduced Healthcare Costs and Lost ProductivityAccidents related to poor air quality, such as explosions caused by methane build-up or oxygen deficiency, can have devastating consequences, leading to fatalities, injuries, and extensive mine closures. Advanced air monitoring technologies act as early warning systems, providing real-time alerts of hazardous conditions. This allows for swift evacuation procedures, minimizing the potential for loss of life and property damage.The economic benefits here are clear; reduced insurance premiums, avoided costs associated with accident investigations and legal proceedings, and minimized downtime related to mine closures. Minimizing disruption to operations is vital for maintaining production schedules and meeting contractual obligations. Continuous monitoring allows for proactive maintenance and adjustments, preventing equipment failures that could further exacerbate safety risks and production delays. Furthermore, by ensuring a safer working environment, these technologies reduce lost productivity due to illness, injury, or absenteeism, directly impacting the mine’s operational efficiency and profitability.Improved Operational Efficiency and Reduced DowntimeBeyond worker safety, advanced air monitoring technologies contribute to improved operational efficiency. Real-time data on gas concentrations enables optimized ventilation By Claudia MangiThe Economic Benefits of Investing in Advanced Air Monitoring Technologies for Mines in Africa

www.africasurveyorsonline.com March-April issue l 2025 23MINING AIR MONITORINGstrategies, ensuring adequate air quality while minimizing energy consumption. This is particularly crucial in large, complex mines where ventilation management is a significant operational cost. Mines can reduce energy expenditure, saving considerable costs in the long run by precisely controlling ventilation based on real-time data. Furthermore, early detection of gas leaks or other atmospheric changes allows for prompt remediation, minimizing downtime caused by unexpected shutdowns or emergency responses. This proactive approach prevents extensive production losses and associated financial penalties.Enhanced Regulatory Compliance and Corporate Social ResponsibilityStringent regulations regarding mine safety and air quality are in place globally. Failure to comply with these regulations can result in significant fines, legal battles, and reputational damage. Many African nations are strengthening their environmental regulations, imposing stricter limits on emissions and waste disposal. Advanced air monitoring technologies provide irrefutable evidence of compliance, minimizing the risk of penalties and reputational damage. This is particularly important for mining companies seeking to attract foreign investment and operate sustainably.Implementing these technologies demonstrates a commitment to corporate social responsibility, enhancing the company’s image and attracting skilled workers who value a safe and healthy work environment. This positive reputation can lead to improved access to financing and enhanced market competitiveness.Increased Asset Life and Reduced Maintenance CostsCertain mine equipment is susceptible to damage from corrosive gases or particulate matter present in the mine atmosphere. Advanced air monitoring can identify areas with high concentrations of these contaminants, allowing for targeted preventative maintenance or protective measures. This proactive approach extends the lifespan of valuable equipment, reducing the need for frequent and costly replacements or repairs. Furthermore, by optimizing ventilation and preventing sudden atmospheric changes, these technologies minimize the risk of equipment damage caused by unexpected events, contributing further to cost savings.Improved Risk Management and Insurance PremiumsInsurance premiums for mining operations are heavily influenced by the perceived risk level. Demonstrating a commitment to advanced safety measures, such as comprehensive air monitoring, can significantly reduce insurance premiums. The investment in these technologies is often offset by lower insurance costs over time. Moreover, advanced data analytics capabilities embedded in these systems can provide valuable insights into potential hazards, enabling proactive risk management strategies. This allows for the identification and mitigation of potential problems before they escalate into costly incidents.Attracting and Retaining Skilled LaborsInvesting in advanced air monitoring technologies also represents an investment in technological advancement and skill development within the African mining sector. In today’s competitive labor market, creating a safe and healthy work environment is crucial for attracting and retaining skilled workers. Mines equipped with advanced air monitoring technologies are more likely to attract and retain talent, reducing recruitment and training costs. The improved safety record and commitment to worker wellbeing enhance the mine’s reputation as an employer of choice. This fosters a more stable and experienced workforce, leading to increased productivity and reduced turnover costs.The Time for Investment is Now Investing in advanced air monitoring technologies for mines offers a comprehensive suite of economic benefits that extend far beyond the initial investment cost. When prioritizing worker safety and operational optimization through real-time monitoring and datadriven decision-making, the mining industry can unlock considerable economic advantages and ensure a more sustainable and profitable future.The transition to these advanced systems is a strategic investment in a safer, more efficient, and economically sound future for the mining sector. The long-term cost savings, improved workforce morale, and enhanced reputation make it a compelling investment for any mining company committed to sustainable and responsible operations. The time for investment is now, to ensure a future where economic growth and environmental and social responsibility go hand in hand. The ability to breathe easy, both literally and figuratively, should be a priority for all stakeholders in the African mining industry.Massive dust explosion at a mining site

24 March-April issue l 2025 www.africasurveyorsonline.comGeophysics relies heavily on accurate and reliable sensor technology. Among the various sensor types are the fluxgate sensors. These sensors are crucial particularly in magnetic field measurements. Fluxgate sensors operate on the principle of magnetic saturation. The sensors utilize a high-permeability core, typically made of a ferromagnetic material like permalloy, which is driven into saturation by an alternating excitation current. This excitation field interacts with any ambient magnetic field, causing variations in the sensor’s output signal. These variations are directly proportional to the strength and direction of the external magnetic field, which allows for a precise measurement. The sophisticated signal processing involved in extracting the ambient field from the excitation signal, and compensating for various noise sources contributes to the high accuracy of fluxgate magnetometers.So, what are the specific advantages that makes fluxgate sensors 2. Vector Measurement CapabilityUnlike some other magnetometer types that only measure the scalar magnitude of the magnetic field, fluxgate sensors provide vector measurements. This means they can simultaneously determine the magnitude and direction (x, y, and z components) of the magnetic field. This information is invaluable for accurately modeling the source of magnetic anomalies, understanding the orientation of magnetic materials, and correcting the effects of sensor orientation during surveys. The vector measurement capability creates more room for a more complete and refined understanding of the magnetic field environment.3. Stability and Low DriftGeophysical surveys often require long-term monitoring and data acquisition. Fluxgate sensors are known for their excellent stability over time, exhibiting minimal drift in their readings. This stability ensures the reliability of long-duration measurements and reduces the need for frequent recalibration, which can be time-consuming and costly. invaluable to geophysicists seeking to unravel the Earth’s hidden secrets.Advantages of Fluxgate Sensors in GeophysicsThe widespread adoption of fluxgate sensors in geophysics is a testament to their numerous advantages, which significantly enhance the accuracy, efficiency, and scope of geophysical investigations. Here’s a detailed look at some key benefits:1. High Sensitivity and ResolutionOne of the primary reasons for the popularity of fluxgate sensors is their exceptional sensitivity. They can detect extremely weak magnetic fields, often on the order of picoteslas (pT) or even femtoteslas (fT). This high sensitivity is crucial in geophysics for identifying subtle magnetic anomalies associated with buried objects, geological formations, and variations in the Earth’s magnetic field. This ability to resolve minute changes in magnetic field strength translates to a higher resolution in geophysical surveys, allowing for more detailed mapping and analysis.Why Fluxgate Sensors Remain a Preferred Choice for Many GeophysicistsFEATUREBy Paul NyakeriDetecting buried features and anomalies for subsurface exploration for geological assessments and resource evaluation

www.africasurveyorsonline.com March-April issue l 2025 25GEOPHYSICS FLUXGATE SENSORSThe low drift characteristic also minimizes errors in data processing and interpretation, ultimately leading to more accurate results.4. Robustness and DurabilityFieldwork in geophysics often involves operating in harsh environments, ranging from extreme temperatures to challenging terrains. Fluxgate sensors are generally robust and durable, capable of withstanding the rigors of field deployment. Their solid-state construction and relatively simple operating principles contribute to their reliability and longevity, making them suitable for use in demanding conditions. This robustness also translates to reduced downtime and lower maintenance costs.5. Low Power ConsumptionMany geophysical surveys are conducted in remote locations where power availability is limited. Fluxgate sensors have low power consumption, making them ideal for use in battery-powered instruments and systems. This is crucial for extending the duration of surveys and minimizing the logistical challenges associated with supplying power to remote field sites.6. Relatively Low CostCompared to some other highsensitivity magnetometers, such as SQUID (Superconducting Quantum Interference Device) magnetometers, fluxgate sensors are relatively inexpensive. This affordability makes them accessible to a wider range of researchers and practitioners, facilitating broader adoption of magnetic methods in geophysics.7. Wide Frequency ResponseFluxgate sensors are capable to operate over a wide frequency range, allowing them to measure both static (DC) and slowly varying (AC) magnetic fields. This is important for various geophysical applications, including:DC Magnetometry: Measuring the static magnetic field of the Earth and identifying anomalies caused by magnetic minerals in rocks and soils.Magnetotellurics (MT): Measuring the naturally occurring electromagnetic fields at the earth’s surface to determine the electrical conductivity structure of the subsurface.Induced Polarization (IP): Measuring the transient voltages that arise after an electrical current is injected into the ground to detect subsurface polarizable materials.The wide frequency response enables fluxgate sensors to be used in a diverse range of geophysical techniques.Applications of Fluxgate Sensors in GeophysicsThe advantages outlined above make fluxgate sensors indispensable tools for a wide variety of geophysical applications, including:Mineral Exploration: Fluxgate magnetometers are extensively used in mineral exploration to detect magnetic anomalies associated with ore deposits, guiding drilling operations, and mapping geological structures. Different types of minerals possess unique magnetic properties. Variations in the earth’s magnetic field caused by these deposits can be detected using fluxgate sensors. This information helps in identifying potential mining targets and guiding subsequent exploration efforts.Archaeological Prospection: Fluxgate sensors are valuable tools in archaeological investigations. Buried structures, such as walls, foundations, or kilns, can alter the local magnetic field, creating detectable anomalies. Highresolution magnetic surveys using fluxgate sensors can help identify and map buried archaeological features, providing crucial insights into past civilizations.Environmental Geophysics: Fluxgate sensors are employed in environmental geophysics to detect buried objects, such as unexploded ordnance (UXO) or pipelines. These objects often exhibit distinct magnetic signatures, making them identifiable through fluxgate surveys. This information is vital for remediation efforts and ensuring public safety.Geotechnical Investigations: Fluxgate sensors are useful in geotechnical investigations by detecting subsurface variations in magnetic susceptibility, which can be related to soil composition and geological structures. This information is valuable for assessing site suitability for construction projects or understanding geological hazards.Marine Geophysics: Fluxgate sensors are adapted for underwater applications, contributing to marine geophysical surveys. They are used to map the seafloor, detect submerged objects, or study the magnetic properties of oceanic crust. These applications provide valuable data for understanding oceanographic processes and geological structures beneath the sea.Geomagnetic Monitoring: Monitoring variations in the Earth’s magnetic field for space weather forecasting, navigation, and scientific research.Navigation and Surveying: Providing accurate heading information for navigation systems and geophysical surveys.Fluxgate Sensors - A Cornerstone of Modern GeophysicsAs technology continues to evolve, fluxgate sensors will remain a cornerstone of modern geophysics, playing a crucial role in unveiling the Earth’s hidden mysteries and addressing critical challenges in resource exploration, environmental monitoring, and hazard assessment. The continuous development and refinement of fluxgate technology promise even greater sensitivity, accuracy, and versatility in the future, further solidifying their position as a vital instrument in the geophysicist’s toolkit.

26 March-April issue l 2025 www.africasurveyorsonline.comFEATURErequirements.”The numerous benefits of ROVs far outweigh the limitations of traditional methods. Let’s explore the key advantages of utilizing ROVs for underwater surveys.Enhanced Safety and Reduced RiskPerhaps the most significant benefit of employing ROVs is the enhanced safety they Administrator at Oceanbotics Inc., highlights, “Subsea robotic vehicles, such as remotely operated vehicles (ROVs), offer significant cost-effectiveness for underwater inspections across various industries, including search and rescue (SAR), offshore oil and gas, and military operations. Their value stems from their ability to provide precise, real-time data while reducing operational costs, risks, and resource Underwater surveys are crucial for a wide range of applications, such as inspecting offshore oil rigs, pipelines, exploring shipwrecks, marine biology research and mapping the ocean floor. These inspections relied heavily on divers, a method that presents significant challenges in terms of safety, cost, and efficiency. As Mira Nagle – Marketing By John MidechaDiving into InnovationWhy ROVs Are Effective for Cutting-Edge Underwater InspectionsAn illustrtion of a ROV inspecting subsea pipeline

www.africasurveyorsonline.com March-April issue l 2025 27UNDERWATER ROVSprovide. Divers face inherent risks associated with working in underwater environments, including decompression sickness, equipment malfunctions, and unpredictable currents. ROVs eliminate the need for human divers in hazardous or challenging conditions, significantly reducing the risk of injury or fatality. This is particularly crucial in deepwater operations or in areas with poor visibility or strong currents, where deploying divers would be exceptionally dangerous. The remote operation allows for surveys to be conducted in environments deemed too risky for human divers, expanding the scope of possible investigations. “The cost-effectiveness of ROVs is most apparent in their ability to conduct inspections in harsh environments where human access is difficult or impossible. In offshore oil and gas operations, ROVs can be used to inspect pipelines, platforms, and other critical infrastructure without the need for extensive human resources. This significantly reduces costs associated with downtime, labor, and logistics,” cites Nagle.Increased Operational Efficiency and Cost-EffectivenessROVs can operate for extended periods without the need for rest breaks or decompression stops, leading to increased operational efficiency. This translates into faster survey completion time, reducing project durations. “In addition to reducing operational costs, ROVs can expedite the inspection process,” says Nagle. “Their ability to operate continuously and remotely means that inspections can be carried out more frequently from anywhere in the world, resulting in quicker identification of issues and faster responses to potential problems. This leads to long-term savings by preventing costly repairs or accidents that might otherwise go unnoticed,” she adds.Improved Data Acquisition and QualityROVs are equipped with a variety of advanced sensors and instruments that can collect high-quality data with significantly greater precision than ordinary methods. According to Nagle, “ROVs also improve the accuracy and quality of data collected during inspections thanks to intuitive software applications, which allow users to review realtime video footage and sonar data.” These sensors can also include laser scanners, and various other instruments tailored to the specific survey requirements. The highresolution imagery and precise data acquired by ROVs provide a level of detail unattainable through traditional visual inspections by divers. This improved data quality leads to more accurate assessments, better informed decisions, and enhanced project outcomes. As Nagle remarks, “This high level of precision helps identify maintenance needs early, allowing for proactive solutions rather than reactive ones, further saving costs for the user.”Accessibility to Challenging EnvironmentsROVs can access areas that are inaccessible or extremely challenging for divers. This includes deep-sea environments, areas with limited visibility, wreck sites, confined spaces, and environments with hazardous materials or unstable structures. Their maneuverability allows them to navigate complex underwater terrains, inspect intricate structures, and reach locations that would be impossible or extremely dangerous for human divers. This expanded accessibility opens up Mira Nagle – Marketing Administrator at Oceanbotics Inc.new opportunities for research and exploration in previously unreachable environments.Environmental ConsiderationsThe use of ROVs in underwater surveys can minimize environmental impact compared to traditional diving methods. Divers often require support vessels and equipment that can disturb marine life and habitats. ROVs, with their smaller footprint and reduced need for surface support, offer a more environmentally sensitive approach to underwater surveys. This is particularly relevant in ecologically sensitive areas where minimizing disturbance is a priority.Optimize Your Underwater Inspections with ROVsThe benefits of utilizing ROVs for underwater surveys are compelling. From enhanced safety and operational efficiency to improved data quality and accessibility to challenging environments, ROV technology has transformed the way underwater inspections and surveys are today conducted. “Overall, utilizing ROVs for underwater inspections is an investment that brings measurable savings by minimizing risks, increasing operational efficiency, and enabling better maintenance practices,” says Nagle. “As industries continue to embrace automation and technology, the cost-effectiveness of ROVs, like the SRV-8, will only become more pronounced,” she concludes. ROVs are undoubtedly fulfilling an even more significant role in various underwater applications, further enhancing a better understanding and management of the aquatic world and its resources. The increasing affordability and sophistication of ROVs make them an increasingly attractive option for a wide range of underwater survey needs, paving the way for safer, more efficient, and more cost effective exploration and investigation of our oceans.

28 March-April issue l 2025 www.africasurveyorsonline.comFEATUREKey Considerations When Selecting a Geodesy Training Program for a Hydrographic SurveyorThe demand for skilled hydrographic surveyors in Africa is steadily increasing, driven by the continent’s need for improved coastal infrastructure and offshore resource exploration. This demand is fundamentally rooted in a strong understanding of geodesy, the science of measuring and representing the Earth’s shape, size, and gravity field. For aspiring and practicing hydrographic surveyors, selecting the right geodesy training program is crucial for career advancement and project success. The availability of high-quality geodesy training programs specifically tailored to the needs of African hydrographic surveyors remains a challenge. Selecting the right program is therefore crucial for career advancement and contributing effectively to the region’s development. Look for programs accredited by internationally recognized bodies like the FIG (International Federation of Surveyors) or national surveying organizations. Accreditation signifies that the program meets specific quality standards in terms of curriculum, faculty expertise, and teaching methodologies. This accreditation is vital for international recognition of your qualifications, particularly in a field as globally interconnected as hydrographic surveying. This article outlines key considerations when choosing a geodesy training program for an aspiring or experienced African hydrographic surveyor, ensuring you make an informed decision that aligns with your professional goals and demand.1. Relevance to Hydrographic Surveying in the African ContextAs much as the foundation in geodesy is paramount, so is the training program which should explicitly address the unique challenges and applications relevant to African hydrographic surveying, such as:• Tropical Climates and Environments: The program should acknowledge the impact of factors like high temperatures, humidity, intense rainfall, and diverse ecosystems on surveying techniques and equipment. Practical training in these conditions is invaluable.• Infrastructure Limitations: Many parts of Africa face infrastructure challenges. The program should incorporate training on working with limited resources, utilizing adaptable technologies, and managing data acquisition in challenging environments.• Specific Regional Needs: Consider the specific hydrographic challenges prevalent in the region where the surveyor will work. This could involve training on shallowwater surveying, port and harbor mapping, river surveys, or the unique challenges of surveying in large lakes.• Local Regulations and Standards: The program should ideally incorporate training on relevant African and international hydrographic standards, regulations, and best practices. Understanding local legal frameworks is crucial for a surveyor’s professional practice.2. Curriculum Alignment with Hydrographic Surveying NeedsA robust geodesy training program for hydrographic surveyors must go beyond theoretical concepts and directly address the practical applications within the field. The curriculum should comprehensively cover topics essential for accurate hydrographic surveys, including:• Geodetic Datums and Coordinate Systems: A thorough understanding of different geodetic datums (e.g., WGS84, NAD83) and coordinate systems (e.g., UTM, geographic) is paramount. The program should emphasize the transformations between these systems and their implications for positional accuracy in hydrographic surveys.• Global Navigation Satellite Systems (GNSS): GNSS technology forms the backbone of modern hydrographic surveying. The training should cover various GNSS techniques, including precise point positioning (PPP), realtime kinematic (RTK), and network RTK, along with error sources and mitigation strategies specific to aquatic environments. Hands-on experience with GNSS receivers and processing software is highly By Dorcas Kang’ereha

www.africasurveyorsonline.com March-April issue l 2025 29desirable.• Geoid Modeling and Orthometric Heights: Accurate depth measurements require understanding the geoid, a model of mean sea level. The program should explain geoid modeling techniques and their role in converting ellipsoidal heights (obtained from GNSS) to orthometric heights (depths relative to mean sea level).• Gravity and Tidal Influences: Tidal variations significantly impact water depth measurements. The training should incorporate principles of physical oceanography, particularly tidal analysis and prediction, and the influence of gravity on water level.• Levelling and Height Determination: Traditional levelling techniques, while less prevalent than GNSS, remain relevant in certain hydrographic applications. The program should offer a foundational understanding of levelling procedures and error analysis.• Data Processing and Analysis: The ability to process and analyze geospatial data is critical. The program should include training on software packages commonly used in hydrographic surveying for data quality control, error adjustment, and geodetic transformations.• Chart production and cartography: Understanding the principles of cartography, including chart symbols, projections, and standards (e.g., IHO standards), is essential for preparing navigational charts. The curriculum should integrate this knowledge into the training.3. Practical Training and Hands-on ExperienceTheoretical knowledge alone is insufficient. A successful geodesy training program should offer ample opportunities for practical application through:• Fieldwork and Data Acquisition: Hands-on experience with GNSS equipment, levelling instruments, and other surveying tools in realistic field settings is invaluable. The program should include field exercises simulating hydrographic survey operations.• Software Proficiency: Training should incorporate the use of industry-standard software packages for data processing, analysis, and visualization (e.g., CARIS HIPS and SIPS, QINSy, Hydrographic S-100 compliant software).• Simulation Exercises: Simulation environments can provide valuable training opportunities in a risk-free setting, allowing students to learn from mistakes and develop problemsolving skills.• Case Studies and Real-World Projects: Analyzing real-world hydrographic survey data and participating in projects allows students to apply their knowledge to realistic scenarios, enhancing problem-solving abilities.4. Instructor Expertise and AccreditationThe credibility of the training program hinges on the expertise of its instructors. Look for programs with instructors who possess extensive experience in hydrographic surveying and geodesy, ideally with relevant academic qualifications and industry certifications.Accreditation is another crucial factor. Accreditation by recognized professional bodies ensures that the program meets specific quality standards and provides graduates with globally recognized credentials. Check for accreditation from relevant organizations like the International Hydrographic Organization (IHO), Skilltrade, or national surveying organizations.5. Program Structure and FlexibilityConsider the program’s structure and flexibility. Does it offer various delivery methods (online, blended learning, in-person)? Does the schedule accommodate your existing commitments? The availability of support materials, such as online resources and dedicated instructors, is also a crucial aspect. Some programs offer short-term courses focused on specific aspects of geodesy, while others offer longer, and more comprehensive programs. You will have to consider the level of detail required and your capacity to commit to the program.6. Programme Cost and FinancingThe cost of the training program is also an important consideration. It is important to choose a program that is affordable and offers financial aid options. Carefully assess the total cost, including tuition fees, accommodation, travel, and living expenses. Also research on funding opportunities, scholarships, and financial aid options that are available to African students and that offer payment plans or flexible financing options.7. Career Support and Networking OpportunitiesA comprehensive geodesy training program should as well provide career support services, such as job placement assistance and networking opportunities with the industry professionals. Connections with potential employers can significantly enhance your prospects after graduation.Take the First Step towards a Successful Career Africa’s safe navigation, coastal management, and resource exploration, depends on a highly skilled and well-trained workforce of hydrographic surveyors, equipped with the knowledge and abilities to tackle the continent’s specific needs. As an African practicing or aspiring hydrographic surveyor, choosing the right geodesy training program is a significant investment in your career future. Considering the discussed key factors, you can make an informed decision that will set you on a successful career path in this crucial and rewarding field. It is always a good idea to seek recommendations from professionals in the field. They can provide valuable insights and advice on which training programs are the best fit for your career needs and goals. Additionally, research thoroughly, compare different programs, and gather valuable insights before making your choice. The right program will be the cornerstone of your professional growth as a skilled and highly sought-after hydrographic surveyor.GEODESY TRAINING PROGRAM

30 March-April issue l 2025 www.africasurveyorsonline.comSeismic refraction surveys are a widely used geophysical method in subsurface investigations. They provide valuable information about geological structures and soil/rock properties. This technique relies on analyzing the travel times of refracted seismic waves to determine the depths, thicknesses, and seismic velocities of subsurface layers. While seemingly straightforward in principle, a successful seismic refraction survey requires careful planning, execution and interpretation. However, a seismic refraction survey is not a ‘one-size-fits-all’ solution. Neglecting crucial considerations can lead to inaccurate results, wasted resources, and ultimately, flawed decision-making based on the derived data. Here are the critical considerations that must be addressed when planning and conducting a seismic refraction survey to ensure reliable and meaningful outcomes.1. Defining the Objectives and Scope of the SurveyBefore deploying any equipment, the primary objective of the survey must be clearly defined. What specific information are you seeking? For instance, are you interested in:• Depth to Bedrock: Determining the overburden thickness above a competent bedrock layer is a common application, essential for foundation design and excavation planning.• Water Table Depth: Refraction surveys can help identify the depth to the water table, which is crucial for groundwater resource management and environmental assessments.• Locating Faults and Fractures: Identifying geological discontinuities like faults and fractures, which can affect slope stability and fluid flow, this is another critical application.• Determining Soil and Rock Properties: Estimating the seismic velocities of different layers allows for inferences about their density, porosity, and strength, providing valuable input for geotechnical models.• Mapping Buried Channels or Structures: Refraction can be used to delineate buried geological features, useful for archaeological investigations or identifying potential hazards.2. Understand the Geological ContextA thorough understanding of the local geology is paramount. This includes reviewing existing geological maps, borehole logs, and any available geophysical data. Prior knowledge of the subsurface stratigraphy, potential geological structures, and the expected velocity contrasts between different layers is invaluable for:• Survey Design: Informed decisions about geophone spacing, spread length, and shot point locations can be made based on the anticipated geological conditions.• Data Interpretation: Geological knowledge helps to validate the seismic refraction results and identify potential ambiguities or limitations.• Ground Truthing: Borehole data can be used to “ground truth” the seismic refraction interpretations, improving the accuracy and reliability of the velocity model.In the absence of existing geological information, a preliminary site reconnaissance is highly recommended. This involves a visual inspection of the area to identify surface features such as outcrops, soil types, and signs of past geological activity.3. Selecting Appropriate Equipment and Survey ParametersThe choice of equipment and survey parameters plays a significant role in the quality of the acquired data. Key considerations include:• Seismic Source: The seismic source generates the energy needed to create seismic waves. Common sources include:• Hammer and Plate: Suitable for shallow investigations and areas with low ambient noise.• Weight Drop: Provides a more powerful source signal for deeper investigations.• Small Explosives: Can be used for deep investigations in areas where permissible.• Vibratory Source (Vibroseis): Used in controlled source seismic surveys, offering high energy and signal control.• Geophones: Geophones are the sensors that detect the seismic waves. The selection of geophones depends on the frequency content of the expected signal and the ambient noise levels. Low-frequency geophones are more sensitive to deeper reflections, while highfrequency geophones are better for resolving shallow features.• Seismic Recorder: The seismic recorder digitizes and stores the signals received from the geophones. The recorder should have sufficient channels to accommodate the desired number of geophones and a sampling rate high enough to accurately capture the seismic Considerations for Successful Seismic Refraction SurveysFEATURE

www.africasurveyorsonline.com March-April issue l 2025 31SEISMIC REFRACTION SURVEYSwaveforms.• Geophone Spacing: The spacing between geophones dictates the resolution of the survey. Smaller spacing provides higher resolution but requires more geophones and longer acquisition times. The optimal spacing depends on the target depth and the expected velocity contrasts. A general rule of thumb is to use a geophone spacing that is approximately one-third to one-half of the expected depth to the first refracting layer.• Shot Point Locations: Shot points are the locations where the seismic source is activated. Multiple shot points are used along the geophone spread to ensure adequate data coverage and to correct for any variations in the near-surface velocity. End shots, offset shots, and reverse shots are common configurations used in seismic refraction surveys.Spread Length: The total length of the geophone spread determines the maximum depth of investigation. The spread length should be at least three to five times the expected depth to the deepest layer of interest.4. Ensuring Data Quality During AcquisitionDuring data acquisition, careful attention must be paid to ensure data quality. This includes:• Geophone Planting: Geophones must be firmly coupled to the ground to ensure good signal reception. Loose or poorly planted geophones can introduce noise and distort the data.•Source Coupling: The seismic source must also be properly coupled to the ground to maximize the energy transfer.• Noise Management: Ambient noise from sources such as traffic, wind, and electrical equipment can interfere with the seismic signal. Measures should be taken to minimize noise, such as conducting the survey during quiet periods or using noise cancellation techniques.• Maintaining Consistent Source Energy: Ensuring consistency in the seismic source energy is crucial for accurate data processing and interpretation.• Real-Time Monitoring: Monitoring the data in real-time allows for immediate identification of any problems with the equipment or data acquisition process.5. Employing Appropriate Data Processing and Interpretation TechniquesThe acquired seismic data must be processed and interpreted using appropriate techniques to extract meaningful information about the subsurface. Common processing steps include:• Gain Application: Amplifying the seismic signal to improve its visibility.• Filtering: Removing unwanted noise from the data.• First Break Picking: Identifying the arrival times of the first arriving seismic waves at each geophone. This is a critical step in the refraction analysis.• Travel Time Curve Analysis: Analyzing the travel time curves to determine the velocities and thicknesses of the different subsurface layers.• Modeling: Creating a velocity model of the subsurface based on the travel time data. Several methods exist, including the PlusMinus method, the Generalized Reciprocal Method (GRM), and tomographic inversion.• Depth Conversion: Converting timebased data to depth estimates using the calculated velocities.It is essential to use appropriate interpretation techniques that account for the limitations of the seismic refraction method. For example, the assumption of horizontal layering may not be valid in areas with complex geological structures. Furthermore, the method is less effective at detecting thin, low-velocity layers or layers with gradual velocity changes.6. Addressing Limitations and Potential Sources of ErrorThe seismic refraction survey has inherent limitations that must be acknowledged. These include:• Hidden Layer Problem: A thin, lowvelocity layer may not be detected if its thickness is insufficient for generating a distinct refraction.• Velocity Inversions: The method assumes that velocity increases with depth. Velocity inversions (where a lower-velocity layer underlies a higher-velocity layer) can lead to inaccurate interpretations.• Dipping Layers: The method is best suited for horizontally layered media. Dipping layers can introduce errors in the depth estimates.• Data Interpretation Ambiguity: Multiple velocity models can sometimes fit the same travel time data, leading to interpretation ambiguity.By acknowledging these limitations and potential sources of error, interpreters can exercise caution and avoid over-interpreting the data. Integrating seismic refraction results with other geophysical and geological data can help to reduce uncertainty and improve the overall accuracy of the subsurface characterization.Careful planning, precise execution, and rigorous interpretation are all critical for obtaining reliable and meaningful seismic refraction survey results. However, the seemingly simple methodology can easily be undermined by overlooking crucial factors, transforming a potentially powerful tool into a source of inaccurate data and wasted resources. This often leads to flawed conclusions and ultimately, poor decision-making impacting various sectors, from civil engineering to resource exploration. Recognizing these potential pitfalls, the need for a comprehensive and adaptable methodology is paramount. This necessitates a systematic approach that addresses the complexities inherent in seismic refraction surveys, ensuring the generated data accurately reflects the subsurface reality. Remember to consult with experienced geophysicists to ensure the successful implementation and interpretation of your seismic refraction survey.

32 March-April issue l 2025 www.africasurveyorsonline.comFEATURELong cable detectors: These detectors use a long cable that is dragged along the ground surface to detect water sources. The cable is connected to a control box that displays the location of the water source.Ground Penetrating Radar (GPR) Detectors: GPR detectors use electromagnetic radiation to detect water sources, providing high-resolution images of subsurface structures. GPR detectors are highly accurate and versatile, making them ideal for scientific research and professional applications. However, they are also the most expensive detector type.Very Low Frequency (VLF) Detectors: These detectors use a low-frequency signal to detect water sources and are ideal for shallow water detection. VLF detectors are userfriendly and affordable, making them popular among beginners and hobbyists.Multi-frequency detectors: These detectors use multiple frequencies to detect water sources. They are highly versatile and can detect water sources in various soil conditions.Pulse Induction (PI) Detectors: PI detectors use a highfrequency signal to detect water sources, providing better depth penetration and accuracy compared to VLF detectors. However, PI detectors are typically more expensive and less user-friendly than VLF detectors.Factors to Consider When Choosing an Underground Water DetectorSeveral critical factors need careful consideration when selecting an underground water detector:Depth of Exploration: The depth at which you need to detect water will significantly influence your choice. The depth range of an underground water detector refers to Top Factors That Influence Your Choice of Underground Water DetectorApplications such as agriculture, construction, environmental studies, disaster relief and well drilling requires reliable underground water sources. Underground water detectors are essential tools for these applications. These devices help locate water sources hidden beneath the ground surface, providing valuable information for well drilling, irrigation planning and scientific research.However, choosing the right underground water detector requires careful consideration of several factors such as such as detector type, frequency, depth range and some additional features. These factors will help navigate the selection process and make an informed decision. Underground water Detector TypeSeveral methods are employed to detect subsurface water, each with varying degrees of accuracy and cost. The most common technologies used in underground water detectors include:Electromagnetic (EM) Detection: These detectors measure the electrical conductivity of the soil. Water, being a good conductor of electricity, creates a measurable difference in the soil’s conductivity compared to drier areas. EM methods are generally more affordable than other techniques but can be susceptible to interference from other subsurface features with high conductivity, like metallic pipes or mineral deposits. They are best suited for preliminary surveys and broad area scans.Resistivity Detection: Resistivity surveys measure the electrical resistance of the soil. Similar to EM methods, water’s high conductivity leads to lower resistance readings. However, resistivity methods offer better depth penetration and resolution than basic EM detectors. They are particularly useful for identifying subsurface layers with varying water content and mapping the extent of aquifers. This method often requires specialized equipment and expertise for data interpretation.Seismic Detection: These methods utilize sound waves to probe the subsurface. Changes in the wave velocity can indicate the presence of water-saturated layers. Seismic methods are often employed for large-scale surveys and are best suited for situations where detailed subsurface information is required. They are generally more complex and expensive than other techniques.By Francis MwambaAn illustration of a water detctor device decting underground water

www.africasurveyorsonline.com March-April issue l 2025 33UNDERGROUND WATER DETECTORSthe maximum depth at which the detector can detect water sources. The depth range varies depending on the detector type, frequency, and ground conditions. When choosing an underground water detector, consider the depth range required for your application. For well drilling or irrigation planning, a detector with a depth range of 100-300 feet may be necessary. However, for hobbyist or recreational use, a detector with a depth range of 10-50 feet may be sufficient.Accuracy and Resolution: The accuracy and resolution of the detector determine the precision of the location and the quantification of water reserves. High-resolution detectors provide more detailed information about the water source, including its size and depth. However, higher resolution often comes at a higher cost.Ease of Use: The user-friendliness of the device is a practical consideration, especially for non-experts. Look for detectors with intuitive interfaces, clear instructions, and user-friendly software for data analysis and visualization. Consider the training and support offered by the manufacturer.Environmental Factors: The geological conditions of the site significantly influence the choice of detector. Factors like soil type, mineral content, and the presence of underground structures can affect the performance of different types of detectors. Some detectors are better suited to specific soil conditions than others. The type of soil will affect the performance of different detectors. EM methods may struggle in highly saline or rocky soils, while GPR can handle a wider range of soil conditions. Knowing the specific soil characteristics is crucial for choosing the appropriate technology.Budget: Underground water detectors range significantly in price, from relatively inexpensive EM detectors to sophisticated and highly priced GPR systems. Set a realistic budget before starting your search, considering the overall cost-benefit ratio.Portability and Durability: The portability and durability of the detector are vital considerations, especially for fieldwork. A lightweight and robust device is essential for ease of transportation and extended use in challenging environments.After-Sales Service and Support: A reliable manufacturer with responsive after-sales service and technical support is crucial. Check the warranty offered, the availability of spare parts, and the manufacturer’s reputation for customer service.Frequency: The frequency of an underground water detector refers to the number of oscillations per second in the detector’s electromagnetic field. Higher frequency detectors provide better depth penetration and accuracy, while lower frequency detectors are better suited for shallow water detection. For instance, a VLF detector with a frequency range of 3-30 kHz may be sufficient for shallow water sources. Whereas, for deeper water sources, a PI or GPR detector with a higher frequency range may be necessary.Technology: The technology used in the detector is a crucial factor to consider. Long cable detectors are ideal for shallow water sources, while pulse induction detectors are better suited for deep water sources. Multi-frequency detectors are the most versatile and can detect water sources in various soil conditions.Area to be Surveyed: The size of the area needing investigation influences the chosen method. Large areas may necessitate the use of more efficient techniques like EM or seismic methods, while smaller areas can be effectively surveyed with GPR or resistivity meters.Brand Reputation: The brand reputation of the manufacturer is also an important factor to consider. Look for a manufacturer with a proven track record of producing high-quality detectors.Recommendations Based on ApplicationFor Agricultural Irrigation: A portable, relatively inexpensive EM detector with sufficient depth penetration for the targeted water table is often suitable. Ease of use is paramount, as many agricultural users may lack specialized training.For Well Drilling: A high-resolution GPR system or a highquality EM detector with deep penetration capabilities is recommended. Accuracy in locating the water source is critical to ensure efficient and cost-effective well drilling.For Geological Surveys: A sophisticated GPR system with advanced data processing software is usually necessary for detailed subsurface mapping and the accurate characterization of aquifers.For Environmental Studies: The choice depends on the specific objectives of the study. Both EM and GPR techniques might be employed, possibly in combination with other geophysical methods, to get a comprehensive understanding of groundwater resources and their interactions with the environment.Making Your DecisionConsulting with experienced professionals and reading detailed product specifications are essential steps before making a purchase or conducting exploration. Investing in a high-quality, appropriate detector can save you time, money, and frustration in the long run. Whether you are a beginner or a professional, there is an underground water detector that is right for you. Always prioritize safety when operating any underground water detection equipment, following all manufacturer’s instructions and safety guidelines.

34 March-April issue l 2025 www.africasurveyorsonline.comFEATURESeismic Innovations How Land Seismic Nodes Are Revolutionizing Oil and Gas ExplorationThe oil and gas industry is constantly seeking innovative technologies to improve exploration efficiency, reduce costs, and enhance the accuracy of subsurface imaging. In recent years, land seismic nodes have emerged as a game-changer, offering significant advantages over traditional geophone-based seismic acquisition methods. These advancements are transforming how energy companies approach subsurface imaging, which leads to better reservoir characterization and ultimately, more successful exploration endeavors. Here are the numerous benefits of using land seismic nodes in oil and gas exploration, highlighting their impact on data quality, operational efficiency, and environmental considerations. Enhanced Data Quality: A Clearer Picture of the SubsurfaceA man at an oil and gas exploration site One of the most compelling reasons 34 March-April issue l 2025 www.africasurveyorsonline.com

www.africasurveyorsonline.com March-April issue l 2025 35LAND SEISMIC NODESfor the adoption of land seismic nodes is the superior quality of data they produce. Traditional geophonebased systems rely on wired cables that are susceptible to various sources of noise and interference. These cables can be damaged, moved by animals or weather, and introduce unwanted vibrations into the acquired data, leading to artifacts and distortions that complicate interpretation.Land seismic nodes, on the other hand, are self-contained recording units that are deployed individually on the ground. Each node contains a three-component geophone, a GPS receiver for precise location, and a data storage unit. This eliminates the need for cumbersome cables, significantly reducing the noise generated by cable handling and environmental factors. The result is cleaner, higher-resolution seismic data with improved signal-to-noise ratio.This improved data quality translates into more accurate subsurface imaging. Geologists and geophysicists can better delineate geological structures, identify potential hydrocarbon reservoirs with greater precision, and characterize reservoir properties more reliably. This ultimately leads to more informed drilling decisions, reduced exploration risks, and increased chances of discovering commercially viable oil and gas reserves. The ability to capture higher frequencies also allows for better imaging of shallower targets and complex geological features, offering substantial advantages in unconventional resource plays like shale gas exploration.Operational Efficiency and Cost Savings: Streamlining AcquisitionThe operational efficiency gains provided by land seismic nodes are substantial. The absence of cables drastically reduces the time and labor required for deployment and retrieval. Teams can deploy and retrieve a significantly larger number of nodes in a given timeframe compared to traditional cablebased systems, leading to faster acquisition times. This streamlined workflow translates directly into cost savings, as fewer personnel and less equipment are needed for the same amount of data acquisition.Furthermore, land seismic nodes can be left in place for extended periods, which allows for repeat surveys or the acquisition of longer offsets. This capability is beneficial in challenging terrains or environmentally sensitive areas, where repeated access and cable laying may be a problem or environmentally damaging. The ability to record data over multiple days also allows for improved signal processing techniques which can further enhance the data quality.Environmental Considerations: Minimizing ImpactEnvironmental concerns are increasingly important in the oil and gas industry. Land seismic nodes offer a more environmentally friendly approach to seismic acquisition compared to traditional methods. The elimination of cables significantly reduces the potential for habitat disturbance and minimizes the risk of damage to vegetation and wildlife. The smaller footprint of node deployments also reduces the overall land area impacted by seismic operations.The reduced need for heavy equipment and personnel movement associated with cable-based systems further contributes to the environmental benefits. This makes land seismic nodes an attractive option for seismic surveys in environmentally sensitive areas, including national parks, forests, and agricultural lands where minimizing environmental impact is paramount. The reduced logistical footprint also benefits from streamlined permitting processes compared to ordinary approaches.Technological Advancements: Continuous ImprovementThe technology behind land seismic nodes is constantly evolving. Ongoing research and development efforts are focused on improving the performance and capabilities of these devices. This includes the development of smaller, more robust nodes with longer battery life and improved data storage capacity. Advancements in data processing techniques are also enhancing the ability to extract even more information from the data acquired by land seismic nodes.The integration of other technologies, such as autonomous driving and drone deployment, further enhances the operational efficiency and safety of node-based seismic surveys. These advancements contribute to a more cost-effective and sustainable approach to oil and gas exploration.A Paradigm Shift in Seismic AcquisitionThe adoption of land seismic nodes represents a significant paradigm shift in land seismic acquisition. The superior data quality, operational efficiency, cost savings, and reduced environmental impact make them a compelling alternative to traditional geophone-based methods. As technology continues to advance and costs decrease, land seismic nodes are poised to become the standard for future oil and gas exploration, contributing to safer, more efficient, and environmentally responsible resource development. The clearer subsurface images provided by node technology ultimately lead to better resource characterization, optimized drilling plans, and a higher probability of successful exploration outcomes.Isometric gas extraction concept with derricks rig truck and different layers of soil isolated \\ Image: courtesy

36 March-April issue l 2025 www.africasurveyorsonline.comNavigating the DepthsFEATUREKey Considerations When Selecting a Multibeam Sonar SystemOne of the most advanced tool available for underwater mapping and surveillance, is a multibeam sonar system. These systems use sound waves to map the seafloor and detect objects in the water column, providing highresolution, three-dimensional data that is crucial for a wide range of applications, such as offshore oil and gas exploration, environmental monitoring, scientific research among others. Therefore, selecting a multibeam sonar system is a significant investment, demanding careful consideration of numerous factors beyond simply the price tag. The optimal system depends heavily on your specific application, operational environment, and budget constraints. But with so many different multibeam sonar systems on the market, how do you choose the right one for your needs? Let’s navigate through the key considerations you should meticulously evaluate before making your purchase decision.1. Application and Operational RequirementsBefore even browsing specific models, define your application precisely. What are your primary objectives? Are you undertaking hydrographic surveys for port development, searching for underwater archaeological sites, inspecting pipelines, or mapping the seabed for offshore renewable energy projects? The answer dictates crucial specifications.For instance, hydrographic surveys demand high accuracy and resolution, necessitating a system with a narrow beam width and superior depth penetration. Conversely, a pipeline inspection might prioritize high-resolution imagery over broader coverage, focusing on a system adept at capturing detailed images of the pipeline’s integrity. Fishery research, on the other hand, may necessitate a system with capabilities for identifying and classifying fish schools.Consider your operational environment. Water clarity, depth range, current conditions, and the presence of obstacles will all influence your system choice. Turbid waters necessitate a system with strong signal processing capabilities to compensate for signal attenuation. Shallow waters might require a system optimized for near-surface operation, minimizing issues like ghosting or surface clutter. Similarly, operating in strong currents may necessitate a more robust and stable By John MidechaIllustration of the basic echo sounding principle and a topographic map of underwater features, illustrating ocean depths

www.africasurveyorsonline.com March-April issue l 2025 37system.2. Sonar Parameters and SpecificationsOnce you’ve defined your application, dig into the technical specifications of various multibeam sonar systems. Key parameters include:Frequency: Higher frequencies generally offer superior resolution but reduced range, while lower frequencies provide greater range but lower resolution. The optimal frequency is a trade-off between these factors, determined by your application requirements.Swath Width: This refers to the width of the area covered by the sonar’s beams. A wider swath width increases survey efficiency but might compromise resolution in certain applications.Beam Spacing: Close beam spacing ensures complete coverage and seamless data acquisition, enhancing the accuracy of the final bathymetric model.Depth Rating: This parameter defines the maximum depth at which the system can operate effectively. Ensure the depth rating exceeds the maximum depth of your operational area, allowing for a safety margin.Accuracy and Resolution: High accuracy and resolution are critical for many applications. Examine the system’s specifications regarding positional accuracy, depth accuracy, and the overall resolution of the acquired data.Data Acquisition and Processing: Consider the system’s data acquisition rate, data storage capacity, and the software’s capabilities for data processing and visualization. A user-friendly interface and efficient postprocessing tools can significantly improve your workflow.Ease of use: A multibeam sonar system can be a complex piece of equipment, with many different settings and parameters to configure. Look for a system that is userfriendly and easy to operate, with clear and intuitive controls and documentation. 3. System Components and IntegrationA multibeam sonar system comprises multiple components, and evaluating their compatibility and integration is critical. This includes the sonar head, processing unit, motion reference unit (MRU), positioning system (GPS or INS), and associated software. Ensure that all components are compatible and seamlessly integrate to provide a reliable and efficient system. The MRU’s accuracy and stability are paramount for accurate data acquisition. The choice of positioning system will impact the overall accuracy of the survey, with high-precision systems such as Inertial Navigation Systems (INS) offering significant advantages in challenging environments.4. Vendor Support and TrainingChoosing a reputable vendor with MULTIBEAM SONAR SYSTEMSstrong technical support and training resources is essential. Consider the vendor’s track record, their response time, and the availability of spare parts and maintenance services. Comprehensive training on the system’s operation and data processing is crucial to ensure proficient utilization and maximize the value of your investment.5. Budget and Cost-EffectivenessMultibeam sonar systems vary widely in price, reflecting differences in capabilities and features. Establish a realistic budget and prioritize features based on their relevance to your specific application needs. Avoid overspending on features you won’t utilize. Consider the long-term costs, including maintenance, repairs, software updates, and ongoing operational expenses. A costeffective system is one that meets your application needs reliably within your budget constraints.A System that Effectively Meets Your Needs Selecting the right multibeam sonar system is a critical decision that can significantly impact the success of your underwater survey or exploration project. Considering the above discussed key points, you can make an informed decision and choose a system that effectively meets your needs and delivers optimal results, allowing you to confidently navigate the depths and unlock the full potential of underwater exploration to achieve accurate, efficient and reliable results. FeatureUnveiling the Earth’s hidden depths to acquire the knowledge needed to safeguard the planet for generations to come has now become a uniquely important goal in which everyone has a role to play. Jamie McMichael-Phillips is director of The Nippon Foundation-GEBCO Seabed 2030 Project. A hydrographic surveyor and former Royal Navy captain, Jamie has worked in a range of leadership roles, from running his own marine data gathering missions to directing defence geospatial strategy and plans for the UK. He has managed governmentto-government relationships for geospatial cooperation and has led on outreach and capacity-building of fledgling organizations in marine data collection, assessment and cartography. Prior to assuming his current role, Jamie chaired the IHO’s Worldwide ENC Database Working Group for over nine years, where he was responsible for monitoring the global footprint of electronic charts required for safe navigation at sea.accounts director for the Americas, based in the Washington DC area. He oversees the development and execution of partnerships with national governments, the United Nations, the World Bank and other multilateral development banks, as well as Fugro’s collaborative science in the region. David also leads Fugro’s global support of and participation in Seabed 2030 and the UN Ocean Decade. A current member of the GEBCO Guiding Committee, he has more than 30 years of experience in ocean mapping, marine geophysics and hydrographic surveys.About the authors Image shows areas of the global seafloor that are considered mapped within the GEBCO grid. The regions coloured grey depict the coverage of mapped areas within the 2022 release of the GEBCO grid and the areas coloured red show the additional coverage included in the 2023 release. (Image courtesy: The Nippon Foundation-GEBCO Seabed 2030 Global Center) A snapshot of the data captured by the multibeam sonar on Oden. The red arrow shows where Oden is, with the hashed area yet to be scanned. Captured by Seabed 2030 Center co-head Professor Larry Mayer on the expedition to the 2019 Ryder Glacier, Greenland.EMPOWERINGWorld leading electric underwater roboticsSaab Seaeyesaabseaeye.com

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