Comparison of topographical ground surveying and satellite-based surveying of a highway in Sohar University, Oman

Highway earthwork is the most cost-consuming stage of highway pavement construction. The basis of earthwork calculations is the estimation of the topography of the area in study. conventional traditional surveying techniques involve the use of measuring tape, theodolite, and the leveling staff. The ground surveying operation is done manually to obtain the three-space coordinates of the area and consequently, obtain the volumes and cost of earthwork required. Although the traditional surveying techniques provide data of high level of accuracy, the process of ground surveying is a time and effort-consuming process, especially in projects involving main highways. Recently, satellite imagery is becoming more available and accessible, representing a more cost-effective method that may replace the traditional surveying methods. Digital elevation models (DEMs), which are obtained from highly developed instruments, can generate the contour map of the area in study. However, there is a lack of data regarding the accuracy level of the elevations obtained by DEMs. Therefore, the precision of such techniques remains unknown. This study involves a case study on an area in Sohar university campus in sultanate of Oman in which a topographic survey is conducted using traditional ground techniques then results are compared to results of a satellite survey of the same area. The comparison is made to evaluate the accuracy of data obtained and assess the adequacy of DEMs in terms of quality, resolution, and precision. Moreover, a comparison of resulting earthwork costs has been made. The findings of this study will help overcome the challenges and limitations of ground topographic surveys and potentially provide more reliable cost-effective methods of highway earthwork surveying using remote sensing techniques.