Suitability of Unmanned Aerial Vehicles for Cadastral Surveys

Abstract

Cadastral surveys in Ghana often employ well known surveying equipment such as Total Station and GNSS receivers or a combination of both. These survey techniques are well-established and widely accepted. However, there are limitations in certain areas. In situations where difficult terrain and inaccessible areas and dense vegetation are encountered or when surveyor’s life may be at risk, Unmanned Aerial Vehicles (UAVs) could be used to overcome the limitations of these well established survey instruments. This research used high resolution images from UAV (DJI Phantom 4) to survey plots within the University of Mines and Technology land area. Coordinates of the boundary points were extracted using Agisoft Photoscan. GNSS receivers were also used to survey the land and the same boundary point coordinates obtained and compared. This enabled the establishment of accurate ground control points for georeferencing. The coordinates obtained from both UAV and GNSS Surveys were used to prepare cadastral plans and compared. The difference in Northings and Eastings from UAV and GNSS surveys were +0.380 cm and +0.351 cm respectively. These differences are well within tolerance of +/- 0.9114 m (+/-3 ft) set by the Survey and Mapping Division (SMD) of the Lands Commission for cadastral plans production. This research therefore concludes that high resolution images from UAVs are suitable for cadastral surveying.