Study on Detection Sensitivity of Star Sensor in Dynamic State

The star sensor's detection sensitivity decreases when in dynamical state. Aiming at this fact,based on the pixel output model and the theory of inspecting signals from noises,the signal-noise-difference ratio (SNDR) criterion deciding whether a pixel can be detected is proposed. The feasibility of taking the w-1m pixel's detectability as the star spot extraction criterion is demonstrated. Corresponding calculation method of dynamical detection sensitivity is investigated. Finally the dynamical detection sensitivity of a star sensor is calculated,compared and analyzed in different given parameters.