Diamond Orbit Accuracy Evaluation For NISAR

NISAR, NASA-ISRO Synthetic Aperture RADAR, is a unique SAR interferrometric mission, that uses sweep SAR and digital beam forming technology, will be planned to fly early next year. Being an interferrometric mission surface deformation studies are one of the prime objectives of this mission. For precision deformation map generation NISAR is planned to fly in a diamond shaped orbital corridor. The repeat pass orbits of NISAR, that are 12 days apart, are to have state vectors within a predefined diamond shape in orbital plane. NISAR’s orbits are maintained within a diamond shape orbital corridor with 325 m in vertical (normal-track) and 250 m in horizontal (cross-track) directions. This article presents a novel approach for NISAR’s diamond orbit accuracy evaluation and validation. We plan to estimate and validate the normal-track (NT), cross-track (CT) and alongtrack (AT) components of the baseline for repeat pass orbits of NISAR. Our approach uses image pairs along with ancillary information and orbit-attitude-time information (OATs) for the estimation of baseline components.