A Comparative Study on Position Fixing with GPS to Ascertain Positional Accuracy

Various techniques have been employed to determine the relative or absolute positions of locations on the surface of the earth to promote effective land management. Continuous Observation Reference Station (CORS) is one of the latest techniques employed in differential GPS positioning. In order to ascertain the positional accuracy of a newly established CORS equipment located on the campus of the University of Mines and Technology (UMaT), this comparative study was carried out. Selected positions around the campus were surveyed and their coordinates computed using a temporarily occupied base and then a CORS base, and the results were compared with the coordinates obtained from a conventional precise traverse. It was observed that the Eastings coordinates obtained from the temporarily occupied reference station compares favourably with those of the conventional method and the CORS with variations in the second and third decimals. Standard errors of -0.144 m and 0.806 m respectively were obtained for the Northings and elevations respectively between the CORS coordinates and that of the conventional method. It was observed that there is a strong correlation between the coordinates of the control points and the relation between the Eastings, Northings and heights were all linear. It could be concluded that the CORS station, which is under study, could be used with minimal error for planimetric and or cadastral surveying purposes.