Comparison of lunar topographic models derived from multiple sources based on least squares matching

Lunar topographic information is of paramount importance for lunar exploration missions and lunar scientific investigations. For lunar topographic models derived from different sources or missions, it is not uncommon to see inconsistencies among them. This paper presents a detailed comparative analysis of lunar topographic models derived from the Chang'E-1 and SELENE altimeter data. A least squares matching method is developed to register one topographic model to the other through a seven parameters transformation (three translation parameters, three rotation parameters, and one scale factor). Two typical study areas on the Moon are selected for detailed investigation, including the Sinus Iridium (the primary candidate landing site area for future Chinese robotic or human landed missions) and the Apollo 15 landing site area. Experimental results indicate that there are small shifts in both horizontal and vertical directions between these two data sets. After the least squares matching and shift removal, the topography derived from the two data sets show a consistent trend.