Spatiotemporal Solar Visibility Modeling for Lunar Landing Site Evaluation

Junseo Moon, Seokju Lee

Keywords: spatiotemporal modeling, lunar landing site evaluation, self-organizing map

Abstract: Lunar landing site evaluation benefits from considering both terrain geometry and time-varying solar illumination, particularly in polar regions where extended eclipses can affect power availability, thermal conditions, and surface operations. We construct a spatiotemporal solar visibility representation over lunar terrain using digital elevation models, DEM-based horizon analysis, and SPICE-derived solar geometry for one synodic cycle. From the resulting binary visibility sequences, we derive mean solar visibility, longest continuous illumination, and longest eclipse duration, and incorporate these descriptors into a self-organizing map (SOM) to generate ranking and suitability maps. We evaluate the method across four lunar south polar regions and at ten previously proposed and three mission-associated coordinates, including Chandrayaan-3 Statio Shiv Shakti, IM-1 near Malapert A, and IM-2 in the Mons Mouton region. Results show that sites with similar mean solar visibility can exhibit different illumination interval structures and suitability outcomes. The site-level comparison further shows that the temporally extended SOM modifies local rank assignments relative to the mean-visibility baseline, with most analyzed coordinates receiving lower, more favorable ranks after temporal descriptors are included. These results suggest that spatiotemporal solar visibility modeling provides information beyond mean solar visibility alone and can support more context-aware lunar south polar landing site evaluation.

Submission Number: 11