TOPOGRAPHIC SURVEY OF A SECTION OF THE UNIVERSITY OF ILORIN, NIGERIA USING UNMANNED AERIAL VEHICLE (UAV) TECHNOLOGY

Purpose: This study evaluates the effectiveness and accuracy of Unmanned Aerial Vehicle (UAV) photogrammetry for generating reliable topographic data within a section of the University of Ilorin, Nigeria. It examines whether RTK-enabled UAVs can serve as efficient alternatives to conventional surveying methods for infrastructure planning and spatial analysis.

Design/methodology/approach: A DJI Mavic 3E UAV with an integrated Real-Time Kinematic (RTK) module was used to capture high-resolution imagery without external Ground Control Points (GCPs). Flights were conducted at about 100 m altitude with 80% frontal and 70% side overlap, yielding a Ground Sampling Distance (GSD) of 2.4 cm/pixel. Data processing in Agisoft Metashape included image alignment, dense point cloud generation, DSM/DTM creation, orthomosaic production, and extraction of topographic features. Accuracy was evaluated using RMSE metrics.

Findings: The study achieved centimeter-level positional accuracy consistent with international geospatial standards. Elevation values ranged from 320–400 m, revealing terrain variability that aids interpretation of slope characteristics, drainage pathways, and infrastructure suitability. UAV-derived outputs proved reliable for land-use planning and geospatial analysis.

Research limitations/Implications: Limitations include reliance on a single UAV platform and study area, which may affect result generalization. Weather, vegetation, and regulatory conditions may also influence data quality. Future research should assess larger areas or integrate other sensors such as LiDAR.

Practical implications: The study supports integrating UAV photogrammetry into the University’s spatial data acquisition framework to enhance efficiency and accuracy in infrastructure planning.

Originality/value: This work demonstrates the capability of an RTK-enabled UAV, specifically the DJI Mavic 3E, to produce precise topographic data without GCPs, highlighting UAV photogrammetry as a modern alternative to traditional surveying techniques.