Open AccessUnmanned Aerial Vehicles for Three‑dimensional Mapping and Change Detection Analysis
Author(s) -
Adetola Olufunmilayo Gbopa,
Emmanuel Gbenga Ayodele,
Chukwuma Okolie,
Akinwumi Olaitan Ajayi,
Chima Iheaturu
Publication year - 2021
Publication title -
geomatics and environmental engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.144
H-Index - 3
eISSN - 2300-7095
pISSN - 1898-1135
DOI - 10.7494/geom.2021.15.1.41
Subject(s) - orthophoto , change detection , remote sensing , drone , terrain , change analysis , ground sample distance , land cover , computer science , satellite , geography , cartography , environmental science , computer vision , pixel , engineering , land use , genetics , civil engineering , physical geography , aerospace engineering , biology
Unmanned Aerial Vehicles (UAVs), commonly known as drones are increasingly being used for three‑dimensional (3D) mapping of the environment. This study utilised UAV technology to produce a revised 3D map of the University of Lagos as well as land cover change detection analysis. A DJI Phantom 4 UAV was used to collect digital images at a flying height of 90 m, and 75% fore and 65% side overlaps. Ground control points (GCPs) for orthophoto rectification were coordinated with a Trimble R8 Global Navigation Satellite System. Pix4D Mapper was used to produce a digital terrain model and an orthophoto at a ground sampling distance of 4.36 cm. The change detection analysis, using the 2015 base map as reference, revealed a significant change in the land cover such as an increase of 16,306.7 m2 in buildings between 2015 and 2019. The root mean square error analysis performed using 7 GCPs showed a horizontal and vertical accuracy of 0.183 m and 0.157 m respectively. This suggests a high level of accuracy, which is adequate for 3D mapping and change detection analysis at a sustainable cost.