Research on Solar Radiation of Von Kármán Crater Using LOLA Data

The Von Kármán crater is one of the candidate landing sites of Chinese CE-4 mission. An effective solar radiation model was established through the improvement of the lunar illumination model based on LOLA data. Then the solar radiation condition of Von Kármán crater in 2018 was numerically simulated and analyzed. The results are as followings. Firstly, the topography strongly impacts the solar radiation, that is, there is more solar radiation in the south crater wall, the north side of the central peak and the south wall of the small craters. What’s more, the solar radiation energy received by the most areas of bottom plain is about （0.9~1） × 10¹⁰ J/m². Also, the solar radiation is more easily affected by latitude without considering the surface slope, the range of which is between 0.87 to 1.01 × 10¹⁰ J/m² from the north end to the south. Thereafter, two candidate landing areas, named regions S1 and S2, were proposed based on surface slope and illumination conditions. The Region S1 is located in the bottom of the southern plain with more flat terrain, sunrise earlier and longer illumination time; while the Region S2 is located in the northwest side of the central peak with more solar radiation energy. The annual average solar radiation energy of the two regions are 9.31 × 10⁹ J/m² and 9.65 × 10⁹ J/m², respectively. The longest illumination time is in July, which is more suitable for landing.