Study of the Fitting Method Used for GPS Leveling in Mining Area

摘要

In a mining area, there are several known GPS control points and the normal height of these points have been measured by leveling, so it is possible to obtain all the height anomalies which can be used to carry out fitting operation and get the quasi-geoid of the mining area. In our study, different fitting methods have been selected, including plane fitting, conicoid fitting, cubic surface fitting, weight by distance fitting, polyhedral fitting and so on. By comparing and analyzing the accuracy of the results of various fitting methods, it can be found that the conicoid fitting is the best. In the future the normal height of each GPS point can be obtained by adding height anomaly rectification to its geodetic height, and the accuracy of transformed normal height can meet the requirement of Class-4 leveling.