A New Algorithm for Star Trackers: Frame Scoring

摘要

This paper presents a new approach to improve the robustness of attitude estimation for centroiding problem. Sometimes, exact centroid positions of the observed stars cannot be estimated accurately. There are many reasons of this fault such as motion blurring, radiation noise (proton effect), lens distortion, sensor faults, etc. In this paper a LIS (Lost-in-Space) algorithm that is robust to centroid errors is described. It presents a scheme including analysis and new techniques such as Shift and ReGroup (SRG) and Proper Combination of Sequences (PCS). SRG technique reveals a reliable way to form the triads in a shifting scheme and PCS offers a solution to non-star space objects problem. Although SRG and PCS increase the time consumption, the use of them boosts the performance of the algorithm in a considerable manner. There are also some parameters of these methods that all be discussed and accurate results could be get by adjusting the parameters. Furthermore, the proposed algorithm has been tested with a simulation environment called as STK (Systems Tool Kit by the company AGI) and it creates a promising success.