Integrated Ground Survey and Remote Sensing Approach for Digital Topographic Mapping of Federal Polytechnic Bauchi, Nigeria

Accurate and up-to-date topographic information is essential for physical planning, infrastructure development and spatial management of institutional environments. This study evaluated the integration of ground-survey observations, high-resolution remotely sensed imagery and terrain data for digital topographic mapping of Federal Polytechnic Bauchi, Nigeria. The mapping workflow combined existing survey control, Global Navigation Satellite System (GNSS) observations, total-station detail and spot-height surveying, high-resolution satellite imagery, Shuttle Radar Topography Mission (SRTM) elevation data and Geographic Information System (GIS) processing. Existing controls provided the spatial reference framework, while total-station observations supplied detailed planimetric and elevation information. Satellite imagery supported feature identification and vectorisation, whereas surveyed spot heights and SRTM data were integrated using inverse distance weighting (IDW) for terrain representation and contour generation. Quantitative reassessment of the archived dataset recovered 220 survey records, comprising 37 three-dimensional spot-height observations and 183 labelled planimetric detail-coordinate records representing nine feature categories. The surveyed spot heights ranged from 644.316 to 656.876m, with a mean elevation of 649.943m, standard deviation of 3.195m and sampled relief of 12.560m. The directly surveyed elevation range differed from the broader terrain range reported from the original SRTM-assisted interpolated surface, demonstrating the importance of distinguishing field observations from model-derived terrain information. The study further showed that the 1m contour interval used in the original map represents a cartographic modelling interval rather than independently demonstrated vertical accuracy. The findings demonstrate that ground surveying, remote sensing and GIS provide complementary information for institutional topographic mapping; however, the reliability of multi-source products depends on geodetic compatibility, preservation of dataset metadata and independent positional and vertical accuracy assessment. The resulting framework provides a basis for systematic campus mapping, spatial planning and future geospatial database updating.