THREE-DIMENSIONAL ASTEROID RECONSTRUCTION VIA MULTI-ASPECT GROUND-BASED SAR IMAGES: AN OPTIMIZATION COMPARISON

Main approaches of observing asteroids rely especially on ground-based optical telescopes, yet not capable of detecting detailed structures of the surface. However, ground-based radar observations can provide delay-Doppler images which help to reconstruct a more accurate shape model. To form the shape model of asteroids, we propose a shape reconstruction method via multi-aspect delay-Doppler radar images and describe the surface through spherical harmonic coefficients. In order to reconstruct shape model as accurate as possible, an optimal solution of the coefficients is required. Three traditional optimization algorithms are applied and performances are compared. When positive decision is made, suitable parameters can achieve effectively with these algorithms followed with an accurately recovered shape of asteroids. Numerical simulations have been conducted to demonstrate the effectiveness of the proposed method.