COMPARATIVE ANALYSIS OF TECHNIQUES FOR ROUTE SURVEY: A CASE STUDY OF DEEPER-LIFE CAMP ROAD, AKURE, ONDO STATE, NIGERIA.

Abstract

Conventional ground survey techniques has been a reliable source of acquiring survey related data from time immemorial but its always laborious and time consuming for large projects. By considering the disadvantages of the ground technique, this research was motivated to explore other methods, which are digital photogrammetry and Satellite Remote Sensing approach for the extraction of route elevations and make comparison of these methods with the conventional ground technique, so as to determine if these methods can serve as replacements for the conventional ground technique for road construction planning in terms of accuracy. Deeper Life Bible Church Camp Road was chosen as the case study. The research involved the acquisition of the elevation data of the road’s centerline and crosssection, using total station instrument, which was term the conventional method. The elevation data for these same points was extracted from digital photogrammetry, through the unmanned aerial vehicle (UAV) method, and satellite remote sensing method, using Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM). The elevation values acquired from UAV and SRTM Digital elevation model (DEM) were compared with the conventional method, using Root Mean Square Error (RMSE) and Z statistics, in order to determine if these method could be a substitute to the conventional method for road construction planning. The results showed that the RMSE value for UAV was 0.23 while it was 6.17 for SRTM, which showed that SRTM has high RMSE value. This implies that the Z statistics also showed that there is no significant difference between the mean of height obtained from the conventional ground and UAV techniques, while there was a significant difference between the mean of height obtained from the Ground and SRTM techniques. It was then concluded that UAV photogrammetry technique can be used as a replacement for conventional ground surveying technique for construction planning. It was recommended that UAV photogrammetry based technique can be used for carrying out route survey due to its flexibility and speed in data acquisition. Also, satellite derived SRTM DEM technique is not recommended for route surveying.