Illumination and communication conditions at the Mons Rümker region based on the improved Lunar Orbiter Laser Altimeter data

Abstract

Abstract Mons Rumker is a large volcanic cluster in Oceanus Procellarum on the Moon, and was chosen as a candidate-landing region for the Chang’E-5 mission. The Lunar Reconnaissance Orbiter (LRO) was launched in 2009, and is still in operation. It acquired a large amount of high-precision laser altimeter data from the Moon, which provided the basis for the construction of a digital elevation model (DEM) and other related research in the Chang’E-5 landing region. We developed a reasonable data processing method based on all of the valid Lunar Orbiter Laser Altimeter (LOLA) data and produced an improved DEM of the Mons Rumker region. A new method combining filtering and clustering was used to eliminate the noise points. Then, crossover adjustment was adopted in order to reduce the root mean square (RMS) of the radial residuals from 1.98\u202fm to 1.31\u202fm. We generated the DEM of the Mons Rumker region using Kriging interpolation. Some errors in the NASA product were revealed by comparing our improved DEM with the NASA DEM. Illumination and communication maps were derived by the improved ray-tracing method using our DEM. Illumination maps showed that the sunlight was abundant in the Mons Rumker region, which was illuminated from 30% to 53% of the study period from November 2017 to December 2019. Moreover, we found that the conditions were favorable for communication between the Mons Rumker region and three Chinese observation stations located at Jiamusi, Kashi, and Neuquen (Argentina). Most regional communications to each station were available for approximately 50% of the investigated period of October 2019. The accumulated communication was less than 16% for only a few craters and on the back of mountains. Continuous communication for 24\u202fh per day at the two example points could be maintained when the three ground stations were synergistically observed.