Discussion on the improvement of the error evaluation method in gravity intermediate area terrain correction based on the measured elevation

In the current gravity survey work, the accuracy of digital elevation model (DEM) used in terrain correction is basically avoided when evaluating the accuracy of terrain correction in gravity intermediate area. Therefore, the mean square error of terrain correction calculated by this data in gravity intermediate area is not comprehensive. Based on the analysis of DEM data error and the comparison of actual data, this paper puts forward a method to evaluate the accuracy of DEM data used for terrain correction in the intermediate area of gravity by using the measured elevation values of gravity measuring points, and discusses how to evaluate the error of terrain correction in the intermediate area of gravity caused by DEM error, so as to obtain the accuracy of terrain correction in the intermediate area of gravity closer to the real situation.