Abstract
Generally, coordinates obtained by global positioning systems (GPS) can be applied when they are transformed into local or national coordinates. The four- and seven-parameter models for GPS coordinate transformation are two of the most frequently used methods. Robust estimation methods are often used to eliminate or weaken the influences of gross errors on coordinate transformation. The current paper employs simulation experiments using different coincident points and the number of gross errors included in the observations to compare the robustness of 13 commonly used robust estimation methods. The results indicate that the L1 and German–McClure methods are relatively more efficient than other robust estimation methods for the GPS coordinate transformation of four- and seven-parameter models.
The authors would like to thank the editor and the two anonymous reviewers for their valued and constructive comments on this paper. This work was financially supported by Shanxi Natural Science Foundation of China (grant no. 2012011015-2).