Optimization on lunar gravity field model using Chang'E-1 orbital tracking data

Abstract

Lunar gravity field is important information to reveal lunar internal structure and element composition, as well as one of the key scientific objects of lunar exploration mission. Using Chang'E-1 orbital tracking data, and in combination with orbital tracking data of SELENE, Lunar Prospector (LP) and historical spacecraft, a high accuracy lunar gravity field model CEGM02 is developed, improvements are shown compared to CEGM01 and other historical models. Analyses show that Chang'E-1 orbital tracking data contribute to long wavelength of lunar gravity field because of its higher orbit altitude than SELENE main orbiter. When compared CEGM02 with SGM100h, there are improvements by a factor of about 2 below degree 5, significant improvements up to degree 10, and contribution to all coefficients until degree 30. Lunar mean moment of inertia 0.393446 (±0.000006) is presented by combining degree 2 coefficients of CEGM02 with lunar laser range results, which can be served as a rather strong constraint in lunar internal structure research.