L- to X-Band Passive Microwave Remote Sensing of the Lunar Regolith

This study presents the potential of L- to X-band wideband radiometry to retrieve important geophysical and thermal properties of the lunar regolith through simulated measurements of a 30-channel 1-10 GHz microwave radiometer. It has been demonstrated that regolith thickness, densification with depth, water ice percentage in the regolith, as well as the geothermal heat flux can be estimated with little (<8%) error and high (>95%) confidence if surface brightness temperatures are collected with such an instrument throughout the entire diurnal cycle. On the other hand, ancillary information regarding other regolith properties such as internal layerings, and the surface density and temperature values may be necessary for a nonunique retrieval; thus, deployment of other instruments such as ground penetrating radars with wideband radiometers would be useful during the future lunar missions.