Study on the Improvement of Ship Position Generation and Star Selection Method for Satellite Navigation Instrument Simulation

To address the significant discrepancy between simulated and actual ship positions in satellite navigation, this paper proposes a novel error generation algorithm. Based on an analysis of probability distribution characteristics within the error circle, the algorithm partitions the area into three concentric regions, each modeled with a uniform distribution but assigned a distinct occurrence probability. Different User Equivalent Range Errors (UERE) are applied during simulation to enhance realism. Furthermore, a satellite selection strategy that directly calculates the Geometric Dilution of Precision (GDOP) for all visible satellites is adopted to improve selection accuracy, thereby achieving more reliable positioning results.