Mapping the Range of Simple Fresh Lunar Crater Ejecta by Analyzing the Scattering Characteristics of the Lunar Regolith Using Mini-RF Data

Lunar crater ejecta can provide important information regarding the impact cratering process and the properties of subsurface materials. However, the mapping of the range of the crater ejecta has been hampered by the degradation of the lunar surface’s morphological features. Polarimetric synthetic aperture radar (SAR) is an effective technique to determine the scattering characteristics of the lunar surface and subsurface, and for distinguishing the fresh crater ejecta from surrounding regions. This letter uses a three-component compact decomposition to process the mini-radio frequency (Mini-RF) data to identify the scattering characteristics of the crater floor, crater wall, crater ejecta of the simple fresh crater, and lunar background regolith. Then, a method for mapping the range of crater ejecta is proposed to obtain the boundary between the crater ejecta and other regions by analyzing the differences in polarimetric scattering characteristics. Using this method, the crater ejecta of six craters were extracted and verified with the range of the ejecta obtained through visual interpretation on SAR imagery, the accuracy of the ejecta range obtained by the proposed method is 82%–95%. The results show that the proposed method can effectively depict the range of the simple fresh lunar crater ejecta.