Quality assessment of DTM generated from RTK GPS data on area with various sky views

Most of civil engineering projects are in large scale applications which need high-resolution DTM. The use of DTM in civil engineering projects has always been assessed from technical and financial point of view, particularly on the data collection stage where greatest time and cost are recognized. Real Time Kinematic GPS (RTK GPS), techniques provides an easy, quick, and efficient alternative for DTM data collection tool. The paper is focused on the experiment aiming to derive a high-resolution DTM by RTK GPS and to assess the quality of the generated DTM, by comparing with Total Station (TS) survey. The assessment also includes an overview on the productivity and efficiency of the technique. Quality measure of the DTM is performed by volumetric accuracy analysis and height error analysis. Experimental result shows that RTK GPS technique can provide a sufficient accuracy to be employed as data collection tool for high resolution DTM generation. It is efficient to be employed as data collection tool for area with average sky view above 50% with about 1.4 times better productivity. Employing RTK GPS for data collection tool on area with average sky view over 60% can produce a good quality of DTM with height errors ranging from millimeters to a few centimeters, and volumetric error of approximately 0.5%.