Computer Simulation Research on the Evaluation of Star Point Positioning Accuracy of Star Sensor

The star point positioning accuracy of the star sensor is an important indicator for evaluating the measurement accuracy of the star sensor. However, the star point positioning accuracy index cannot be directly measured by laboratory or outside experiments. In this paper, a method for indirect evaluation of star positioning accuracy of star sensors is proposed. Firstly, the definition of the star diagonal distance of the star sensor is given, and the imaging model of the star sensor is established. On this basis, the formula for transmitting the position error of star point is derived. A large number of simulation calculations are carried out by computer simulation method, and the quantitative relationship between standard deviation of Star diagonal distance and that of star position is obtained. The results show that under the condition of high-precision calibration of the focal length, there is a linear relationship between the standard deviation of star diagonal distance and that of star point position, and the standard deviation of star diagonal distance is about 1.42 times that of star point position. Therefore, star diagonal distance error of the star sensor can be measured and calculated through laboratory or outside experiments, and then star position error can be calculated with the method in this paper, so as to realize the evaluation of star positioning accuracy.