Review on the in-situ spectroscopy and radar remote sensing on the Moon

This paper presents a review of the scientific research progress of the lunar in-situ spectroscopy and radar, focusing on the important results obtained by the Chang'E-3 and Chang'E-4 missions. In terms of the spectral detection, we report the composition, the photometric characteristics, space weathering information and thermal radiation characteristics of the lunar surface. In terms of radar detection, the detection of geological subsurface structures of the Moon, the detection of possible cavities/lava-tubes, and the inversion of the dielectric properties of the lunar regolith are described. Finally, the future development trends of lunar in-situ spectroscopy and radar detection are discussed.