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A New Method for Simulation of Lunar Microwave Brightness Temperatures and Evaluation of Chang'E‐2 MRM Data Using Thermal Constraints From Diviner
Author(s) -
Wei Guangfei,
Li Xiongyao,
Gan Hong,
Blewett David T.,
Neish Catherine D.,
Greenhagen Benjamin T.
Publication year - 2019
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
eISSN - 2169-9100
pISSN - 2169-9097
DOI - 10.1029/2018je005858
Subject(s) - brightness temperature , radiometer , microwave radiometer , microwave , brightness , remote sensing , astrophysics , physics , geology , optics , quantum mechanics
We used the bolometric brightness temperatures (T Bol ) derived from the Lunar Reconnaissance Orbiters Diviner Lunar Radiometer (Diviner) as an upper boundary condition in our thermal model. We then calculated temperature profiles at any local time based on our improved thermal model at low to middle latitudes (70° N/S). Based on the temperature profiles, we modeled the midnight brightness temperature at 19.35 (T B19 ) and 37 GHz (T B37 ). Comparing to the Chang'E‐1 and Chang'E‐2 (CE‐1/2) observations, we found that CE‐1 showed a better data quality than that of CE‐2, especially for the T B37 data. Assuming that the issue with the CE‐2 data is caused by heat contamination of the cold‐reference antennas, we performed an empirical normalization of the CE‐2 microwave radiometer data near midnight following the approach of Hu et al. (2017). The results show that T B difference (modeled values minus modified T B ) for 19.35 GHz is less than 3.40 K for ∼80% of the pixels. At 37 GHz, ∼67% of the pixels have T B difference less than 2.88 K. Additionally, we identified some areas of low microwave temperature in our modified T B maps. These low‐T B features can be characterized by two types: (1) low T B spots at fresh craters with high rock abundance and bright rays and (2) high‐Ti lunar mare surfaces with a low content of rock fragments. Investigating these low‐T B regions with the modified T B data can reveal more information about subsurface thermal regime and properties and help us better understand the evolution of regolith on the Moon.