Inversion Of Temperature-related Lunar Regolith Dielectric Constant Based On Brightness Temperature Data Of CE-2

The dielectric constant is the basic physical parameter of the lunar soil, and the accurate lunar regolith dielectric constant parameter model is important for the active and passive microwave remote sensing and quantitative extraction of the remote sensing parameters. The current dielectric constant model has not considered the influence of the physical temperature, however, the study shows that the dielectric constant is related to the physical temperature. In this paper, an temperature-dependent lunar regolith dielectric constant is inversed based on the Chang'E-2 brightness temperature(TB) data and Diviner Lunar Radiometer Experiment(DLRE) infrared TB data, and the temperature profile is improved. The model of microwave band lunar regolith dielectric constant is proposed.Firstly, this paper introduced the multi-layer lunar microwave TB model, and analyzed influence to TB caused by topography, physical temperature profile and lunar regolith dielectric constant. Then, the measured TB data from CE-2 is normalized in space and time to obtain the space-time normalized temperature deviation?. The surface physical temperature data is obtained by the DLRE infrared TB data. The correlation between ? of different temperature section and the abundance of FeO and TiO2 is analyzed. The results show that a higher the temperature means the bigger the correlation coefficient. Therefore, the physical temperature will affect the lunar regolith dielectric constant.To solve equation of heat conduction for temperature profile, the result compared with measure physical temperature is no match very well. In order to obtain more accurate temperature profile, this paper proposes an improved method that according to the measured surface temperature to find corresponding temperature profile. In order to inverted dielectric constant, the CE-2 TB data are selected through different temperature sections. Moreover, the multi-layer lunar microwave TB model and the multivariable constrained optimization method are used to invert the lunar regolith dielectric constant model. The inversion results show that with the increasing of temperature, the increase of loss tangent. The along-track TB is calculated in order to verify the accuracy of the inversion results, the root mean square deviation of simulated TB and measured TB are less than 7K, which is better than former lunar regolith dielectric constant.