Correction of Star Catalog Positional and Proper-motion Systematic Errors for Natural Satellite Astrometry

Abstract

Precise orbit determination of natural satellites relies on the consistent combination of heterogeneous astrometric observations spanning long time intervals. However, the use of different reference star catalogs introduces spatially correlated systematic biases that degrade data consistency and limit orbit accuracy. In this work, we construct a unified correction framework based on the Gaia DR3 reference frame and derive position and proper-motion corrections for 17 star catalogs commonly used in natural satellite astrometry. The method employs rigorous epoch propagation, HEALPix-based spatial partitioning, and robust median statistics to estimate local systematics, and reconstructs a continuous correction field using radial basis function interpolation. The derived corrections reveal a clear hierarchy among the catalogs: modern catalogs exhibit systematics at the milliarcsecond level, whereas older photographic catalogs show position offsets reaching the 100 mas to arcsecond level. This framework provides a consistent basis for reprocessing historical observations and improves the astrometric accuracy of natural satellite observations, thereby enhancing the precision of orbit determination and dynamical studies of natural satellite systems.