Stellar Scene Simulation for Indoor Calibration of Modern Star Trackers

This paper analyses some aspects dealing with indoor testing of modern star trackers for attitude determination. An end-to-end approach has been considered, which requires that realistic star field scenes are simulated and supplied to the sensor under test. First of all, the features of the scene that is observed during a space mission are presented. Characterising astronomic parameters are converted into radiometric quantities to be directly exploited for simulation. Then, the need of collimating optics to reproduce the huge distance of the true scene is demonstrated by quantitative analysis of typical sensor performance. Relevant design is also presented. Finally, the relationship between the accuracy of sensor installation in the test facility and the consequent attitude measurement uncertainty is evaluated.