Simulation Study of Geometric Characteristics and Coverage for Moon-Based Earth Observation in the Electro-Optical Region

Large-scale geoscience phenomena are increasingly attracting more attention because of their great scientific and social significance. However, many existing earth observation systems lack the ability to conduct long-term continuous observations at a regional-to-global scale because of spatial and temporal coverage limitations and systematic bias. In this work, we propose a new platform, the moon, and discuss its potential and optical geometrical characteristics for observing large-scale geoscience phenomena. Based on the Jet Propulsion Laboratory ephemerides, the reference systems transformation and a simulation system of moon-based earth observations were developed. Numerous experiments were carried out and a series of simulation images are presented, which illustrate the wide swath and continuous observation characteristics of such a lunar observatory. In order to quantify the performance of moon-based earth observations, a simplified geometrical model was constructed and data were analyzed. The sublunar points were found to be unique parameters with the ability to characterize the relative positions between moon and earth. We also defined an effective coverage parameter for assessing the optical coverage ability of moon-based earth observations. The calculation showed that the average value of the introduced coverage parameter from 1960 to 2050 was 0.500, and the coverage remained stable in different years. Furthermore, the total daily visible time and repeated times of different positions on the earth surface are analyzed and the effect of different positions on the lunar surface of the observatory are evaluated. The result shows that such a moon-based approach could make significant contributions to the monitoring and understanding of large-scale geoscience phenomena.