OBSERVATION ANGULAR ANALYSIS FROM A MOON-BASED EARTH OBSERVATION PLATFORM

To deepen the understanding of the Moon-based Earth observations, we establish a new kind of expression of the observation angle. Considering the Earth as a single point, the relative azimuth angle and viewing zenith angle of a Moon-based platform are defined. We first summarize the general procedures of the geometrical model. Based on the geometrical model, the positions of the Sun, the Earth, and the Moon can be acquired. Then, the new expressions of the observation angles are defined in the International Terrestrial Reference System (ITRS). The relative azimuth angle is related to the solar direction, while the viewing zenith angle describes the relationship between the lunar position and the Earth Equator. Results revealed the characteristics of the viewing zenith angle and relative azimuth angle, demonstrating the features of Moon-based Earth observations.