Application of Space-Wise Least Square Method to Error Analysis for Satellite Gravimetry

The performance of satellite gravimetry is determined not only by orbital parameters, sensitivity of payloads, resolution of data, et al, but also by inaccuracy of the Earth gravity recovered methods. In past years, the performance analysis results were unavoidably affected by the mathematical model error from recovering methods such as dynamic method, short-arc integrated method, et al. To solve this problem, space-wise least square method is present. The effects of each items which affected the performance of satellite gravimetry are evaluated by this method. The results indicate that the highest degree of the earth gravity model recovered is 240 for the satellite with 500 km orbital height. Then if the error of payload is 1×10^-10 m·s^-2·Hz^-1/2, the degree of model recovered only approach to 136 with the accumulated gravity anomaly error 2.7 mGal and the accumulated geoid height error 14 cm. In order to achieve the best surveying performance, the orbital inclination should be greater than 89°. While, the max degree of the earth gravity model recovered should be greater than 240 so as to reduce the effect of high frequency gravity signal on low degree coefficients recovered. All these conclusions benefit to satellite designing and data processing.