Post-flight Evaluation of Lidar-based Digital Terrain Models for OSIRIS-REx Navigation at Bennu

Abstract The Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) spacecraft spent more than 2 yr characterizing near-Earth asteroid (101955) Bennu. OSIRIS-REx Laser Altimeter (OLA) was responsible for producing the most accurate reconstruction of asteroid’s surface—down to a global resolution around 5 cm with data precision ±1.25 cm. However, best-quality OLA digital terrain model (DTM), version 21 (v21), not available navigation during proximity operations, nor utility this evaluated processing images altimeter navigation. focus paper is post-flight assessment final v21 DTM, its performance navigation-related analysis, estimates corrections needed DTM measurement models. We created 15 maplets optical (OpNav) data, DTMs estimate combined trajectory over five phases mission. Our estimated instrument produce residuals 7.12 (1 σ ; one standard deviation from mean). OpNav image at 0.2 px ) landmark locations ±6 cm, outperforming requirements. Finally, our scale precise within 1.1 previously reported values. find that slight discrepancy persists between suggesting too small by 0.049%, but nevertheless exceptional