Chandrayaan-2 Onboard Results for Lander Horizontal Velocity Camera and Improvement for Chandrayaan-3

This paper presents the on-orbit performance results of Lander Horizontal velocity camera (LHVC) obtained in Chandrayaan-2(CH-2) and the improvements carried out for Chandrayaan-3 (CH-3). LHVC computes velocity of Lander while descending by comparing two images using phase correlation image registration algorithm. LHVC was operated in various orbits and at various sun angles with respect to moon and the robustness of the sensor is seen in the results. Based on the Lander dynamics observed in CH-2, improvements are carried out in LHVC for minimum velocity measurement and rotation angle tolerance. The improvements are tested and the results are also presented.