Lunar Brightness Temperature Map and TB Distribution Model

The microwave radiometer (MRM) on-board the Chinese Chang'e-2 (CE-2) lunar probe measures the lunar brightness temperature (also referred to as TB) data that are large-scale scientific data. In order to construct lunar TB map, the optimized hierarchical MK splines method is proposed, which uses a hierarchy of coarse-to-fine control lattices to generate a fine control lattice. The computation of the TB construction function is limited to the small number of control points in the merged control lattice, and then the desired high-resolution TB maps are constructed. At the same time, some basis relations between the lunar TB and frequencies are also analyzed based on the constructed TB maps. It can be found that the high-frequency TB map shows lunar topographic features with close similarity. Furthermore, to express the TB distribution features quantitatively, the lunar TB distribution models, including the global TB model of the Moon, the TB model of the lunar far side, and the TB model of the lunar near side, are established based on the constructed TB maps, and the obtained TB distribution models are log-normal distributions. The establishment of the lunar TB distribution model is important to reasonably select the color layer and intensity of color for the lunar TB maps, and is helpful for studying the lunar TB distribution law. In addition, the topographic data measured by the lunar orbiter laser altimeter are selected to discuss the influence of elevation on the lunar TB, and the CE-2 TB data combined with the FeO and TiO
₂
abundances are used to study the microwave thermal emission features of the lunar regolith. The research results have important implications for studying the thermal radiation of the Moon.