Key Laboratory of Wave Scattering and Remote Sensing Information (MoE), Fudan University, Shanghai 200433, China

China’s first lunar exploration project, Chang-E 1 (CE-1), a multi-channel microwave radiometer was aboard the satellite, with the purpose of measuring microwave brightness temperature from lunar surface and surveying the global distribution of lunar regolith layer thickness. In this paper, the primary 621 tracks of swath data measured by Chang-E 1 microwave radiometer from November 2007 to February 2008 are collected and analyzed. Using nearest neighbor interpolation based on the sun incidence angle in observations, global distributions of microwave brightness temperature from lunar surface at lunar daytime and nighttime are con- structed. Using the three-layer model (the top dust-soil, regolith and underlying rock media) for microwave thermal emission of lunar surface, the measurements of brightness temperature and dependence upon latitude, frequency and FeO+TiO₂ content, etc. are discussed. On the basis of the ground measurements at Apollo landing sites, the observed brightness temperature at these locations are validated and calibrated by numerical three-layer modeling. Using the empirical dependence of physical temperature upon the latitude verified by the measurements at Apollo landing sites, the global distribution of regolith layer thickness is then inverted from the brightness temperature data of CE-1 at 3 GHz channel. Those inversions at Apollo landing sites are com- pared with the Apollo in situ measurements. Finally, the statistical property of regolith thickness distribution is analyzed and discussed.

This work was supported by the National Natural Science Foundation of China (Grant Nos. 60971091, 40637033), the State Key Laboratory of Remote Sensing Science (Grant No. 2009KFJJ011). Multi-channel radiometers of Chang-E 1 were designed by the Space Science and Application Center of Chinese Academy of Sciences. The data were provided by the Lunar Exploration Engineering Center of China. We thank Prof. Jiang for guidance and assistance.