TOPOGRAPHIC ANALYSIS OF CHANG’E-4 LANDING SITE USING ORBITAL, DESCENT AND GROUND DATA

Abstract. The Chang’e-4 (CE-4) probe, which includes a lander and a rover, was successfully landed in Von Kármán crater inside the South Pole-Aitken basin on January 3, 2019. Landing site mapping and topographic analyses have been performed at different scales using orbital, descent and ground data to support mission operations and various scientific investigations. We produced a 0.9 m-resolution seamless digital orthophoto map (DOM) mosaic of the CE-4 landing site region covering 51 km × 30 km using 100 Lunar Reconnaissance Orbiter Camera (LROC) Narrow-Angle Camera (NAC) images. Within an area of 3.2 km × 3.0 km of the the DOM around the lander, more than 11,000 craters with diameter greater than 5 m have been identified and measured. A 0.03 m- resolution DOM, which covers an area of 211 m × 187 m, was generated using descent images, and has been used as one of the base maps for overall rover traverse planning. During surface operations, local DEMs with 0.02 m resolution are routinely produced and topographic analysis have been performed at each waypoint using Navcam images and at some locations using Pancam images, to support waypoint-to-waypoint path planning, science target selection and scientific investigations.