Comparative Evaluation of The Accuracies of Differential GPS and Total Station in Determining the Coordinates of Existing Controls

Abstract

A Control survey is a survey operation that is carried out in order to establish position of points with a high degree of accuracy in order to support activities like mapping and map revisions, property boundary surveys, construction projects and so on. Control densification is a continuous exercise in the field of geomatics. This forms the basis upon which other geomatics and engineering activities geared toward development are referenced. This study is aimed at determining the coordinates of existing control points network along Ayetoro / Egbeda Atuba road using dual frequency GPS and Total Station with a view to comparing the accuracies of DGPS and Total Station using statistical analysis to determine which one has better accuracy. The Objectives of the study are to locate the existing control points, to collect the information/coordinates of the existing control points, and to carry out the observation using DGPS and Total station and process/compute the final coordinates and compare the results by using statistical analysis. The methodology that are adopted for this project is Satellite Positioning Technology using Differential Global Positioning System (DGPS) and Total Station. And the acquired data was processed and adjusted. The statistical analysis was used to compare the result obtained from DGPS and Total Station with the data collected from the Ministry of Land and Housing. The result of the analysis shows that DGPS has better accuracy. It is recommended that whenever more suitable and accurate method of measurement is to be employed, the DGPS method should be selected as this study has demonstrated and compared the accuracy of the two methods and showed that the DGPS method is better.