Accuracy Evaluation of Using (GPS) for Surveying Applications

Abstract

In recent years, there has been a huge rise in the amount of remote sensed data collected by an ever-increasing number of earth observation sensors. This increase in usage requires a study of remote sensing techniques accuracy used in various land surveying applications. This research presents an accuracy assessment study of using GPS observation technique (kinematic) for two surveying applications (Building and Road Survey) and assesses its behavior with classical surveying techniques. During this research field tests were conducted to reflect characteristics of GPS collecting observations techniques. The experimental work is primarily divided to two main categories. Firstly,traditional survey by using total station.In this survey, two methods have been used which are (Resection and Back sight). The observed coordinates for building and road survey were about 90 points. Secondly,modern survey using GPS_GR-3 have been conducted by using (RTK- Real Time kinematic) technique. The results of this research suggest that using GPS technology for surveying applications is very important to save cost and time with acceptable accuracy. After compare the results of Total Station with the results of GPS in the road survey, the longitudinal section of road has a difference by around +13.6cm with RMSE of 0.094m. This accuracy is suitable for creating the contour maps. It can concluded also that RMSE for buildings survey using GPS (Kinematic) technique comparing with classical survey observations is 0.066 m, with difference by around +7cm.