Development of the fine lunar gravity field modeling with digital elevation model

The fine modeling of the lunar gravity field is a fundamental task for establishing lunar altitude references, conducting research on lunar interior structure, and other scientific endeavors. The lunar gravity field model constructed solely based on spacecraft orbit data has limited spatial resolution, making it challenging to meet the demands of fine gravity field research. The acquisition of high-resolution terrain models presents new opportunities for the study of precise lunar gravity fields. This paper reviews the current status and advancements in fine lunar gravity field modeling, including research efforts and evaluation methods for global lunar gravity field models, principles and technologies for fine gravity field modeling, as well as related research outcomes. On this basis, this paper systematically summarizes the key theoretical issues and technical challenges in the theory of lunar gravity field modeling based on high-resolution terrain models. These include data updating, error correction in high-frequency gravity field modeling, calculation efficiency, and the series divergence problem in spherical harmonic analysis. In addition, future research directions are discussed. This work will provide references for gravity field research on the Moon and other terrestrial planets.