ROBUST ESTIMATION AND OPTIMAL SELECTION OF POLYNOMIAL PARAMETERS FOR THE INTERPOLATION OF GPS GEOID HEIGHTS

The polynomial interpolation of least squares and interpolation moving least squares based on control stations with known GPS (global positi oning system) ellipsoidal heights and levelling orthometric heights ar e the most often used methods for the interpolation of the geoid heigh ts. But in their applications there occur two problems: one lies in se lecting the suitable polynomial parameters; the other in reducing the influences of some possibly abnormal data points. To solve both of the problems, without emphasizing a sound theoretical basis, a heuristic solution with the help of robust estimation technique and optimization criteria for the regression equation is presented. Through two actual numerical examples it is shown that the new solution concept is effic ient and can be realized easily on computers.