Near-earth space star map simulation method of short-wave infrared star sensor

Abstract

In order to solve the problem of insufficient short-wave infrared star map data for the near-earth space star sensors' performance evaluation and the hardship of characterizing the disturbance factors dominated by the atmosphere on the star map quality. Based on the coordinate conversion, energy transfer, and image quality degradation, a star map simulation method for near-earth space SWIR star sensor is proposed. The atmospheric disturbance factors considered include atmospheric background, refraction, turbulence, and aerosol-scattering. According to the presented simulation method, combined with the designed simulation process and the set input conditions, the simulation results of the star map at 0 km altitude are given. The simulation results show that the stronger the sky background is, the larger the star map gray mean and the RMS of noise are, and the more extensive the gray mean and peak value of the 3x3 pixels where the star point is located; the larger the view zenith angle, the more significant the star point centroid offset. The star map quality is quantitatively evaluated based on assessment indicators and further verified based on the measured data. The evaluation and verification outcome support the inference given by the star map simulation results and illustrate the rationality of the star map simulation method. The paper can provide technical support for the optimization design, capability estimation, and algorithm validation of the near-earth space SWIR star sensor.