Research On Lunar Regolith Dielectric Constant Retrieve Based On The Multichannel Microwave Radiative Brightness Temperature Of Chang'E

In order to establish an accurate lunar microwave TB model, an accurate lunar regolith dielectric constant model is necessary since it is a key factor to the microwave brightness temperature(TB) of lunar surface. The model of lunar regolith dielectric constant is inversed based on the multichannel(19.35 GHz, 37GHz) microwave TB data, and the inversion results is analyzed in this paper.Firstly, this paper introduced the multi-layer lunar microwave TB model and the main parameters in the model, and analyzed the influence to TB caused by these parameters such as lunar regolith density, physical temperature profile and lunar regolith dielectric constant. It is shown that the influence to TB contributed by the abundance of OFe and 2TiO is related to the impact to lunar dielectric constant model made by the abundance of OFe and 2TiO. Then, the measured TB data from CE-1 is normalized in space and time to obtain the daytime scaled temperature deviation? of the lunar surface. The correlation between the daytime ? and the abundance of OFe and 2TiO is analyzed as well as the correlation between the lunar microwave TB in equatorial noon time and the abundance of OFe and 2TiO. The results show that the impact to TB caused by the abundance of OFe and 2TiO is inconsistent, which leads to the conclusion that it is not appropriate to simply take the abundance of OFe and 2TiO as a whole in lunar regolith dielectric constant model. In another word, discusses on the impact caused by OFe and 2TiO should be launched separately.Based on the CE-1 microwave TB data, the lunar regolith dielectric constant model is inversed. In order to determine the form of lunar dielectric constant model with parameter, the change of measured TB along with the abundance of OFe and 2TiO, and the variation trend of the simulated TB from the existed lunar regolith dielectric constant model made by the abundance of OFe and 2TiO are compared at first. Moreover, the multi-layer lunar microwave TB model and the multivariable constrained optimization method are used to inverse the lunar regolith dielectric constant model, on the basis of the correlation between the measured daytime ? from CE-1 on 19.35 GHz and 37 GHz, and the abundance of OFe and 2TiO. The results show that the variation trend of ? simulated from the inversed lunar regolith dielectric constant model is largely consistent with the trend of measured ?, so as the change trend of the simulated lunar microwave TB in equatorial noon time by using the inversed lunar regolith dielectric constant model and the measured TB. The validity of the inversed lunar regolith dielectric constant model could be safely arrived from relative values and absolute values of TB.