Evaluation of vertical accuracy of DEM produced using Google Earth coordinate.

At the beginning of the last decade, Google Earth data became the most popular program used by researchers and students. Several companies supplied their high-resolution images to Google Earth, which is deserve to examine its positional accuracy. Two stereo pairs of Pleiades images with 0.5 meter spatial resolution cover a border open area in eastern Iraq, al-Wend Dam, Khanaqeen, and Deyala governorates, to produce a DEM (Digital Elevation Model) and evaluate its vertical accuracy. The GNSS survey is usually one of the most accurate data sources used to evaluate the DEM vertical accuracy, but it is expensive, time-consuming, and requires a lot of effort in addition to the significant security risks. In this study, we try to replace the GNSS field survey by using selected 3D position coordinates from Google Earth Pro as reference data. Two data sets were acquired in this study. The first data set represents a GNSS field survey for the study area for ground control points by fast static technique, and the second data set is RTK (Real Time kinematic) for checkpoint survey. The second data set was 3D position coordinates from Google Earth Pro. From these data sets, producing DTM1 and DTM2 respectively, and evaluating their vertical accuracy, the results show that the vertical accuracy, depending on ground control points of each DTM1, DTM2 was 0.5352m, 1.184m, and 1.142608m, 3.417807m depending on checkpoints. This provides an index of the vertical accuracy for Google Earth Pro. 3D coordinates, which is less than three times the accuracy of a GNSS field survey in the study area. [ABSTRACT FROM AUTHOR]