MERcury Gravity REcovery and Analysis System (MERGREAS) and its performances from simulated four-way Doppler measurements
Abstract
The exploration of the planet Mercury requires software applications that can execute Precise Orbit Determination (POD) and estimate dynamic parameter solutions. In this paper, we present MERcury Gravity REcovery and Analysis System (MERGREAS), a new software product that is designed to support the future Chinese Mercury explorations. To validate the software we crosschecked the MERGREAS functionalities against the GEODYN-II. Simulated orbit determination experiments show that the differences between MERGREAS and GEODYN-II in the X, Y , and Z directions were 0.2, 0.7, and 0.5 m respectively with the arc length of 24 h. The integration interval for both software platforms was 10s. The MERGREAS software can utilize four-way Doppler measurements for spacecraft orbit determination as well as precise positioning of a Mercury lander. In simulations, we show that when the four-way Doppler data are included, the accuracy in Mercury spacecraft orbit determination can reach the centimeter level and the lander positioning accuracy can be refined to decimeter Electronic supplementary material The online version of this article (