Star map simulation and platform influence of airborne star sensor based on J-band data of 2MASS catalog

Abstract

In order to solve the problem of insufficient star map data for airborne star sensor algorithm testing and the difficulty in characterizing the effect of airborne platform motion on image quality of airborne star sensor, this paper carries out star map simulation and platform influence research on airborne star sensor based on J-band data of 2MASS catalog. Based on the analysis of the star target characteristics in the J-band of the 2MASS catalog, the imaging link model of the star sensor and the analysis model of the influence of platform motion on the imaging are constructed. According to the input simulation conditions, the simulation of sequence star map is realized. Based on the features of star map recognition algorithm, the quality evaluation index of star map is constructed, and the influence of platform motion on the quality of star map is analyzed. The star map simulation results show that the minimum SNR of the simulated star map is 8.45 dB for −1~6 magnitude stars, which can meet the requirements of star point extraction, star pattern recognition and attitude solution algorithm performance evaluation for daytime airborne star sensors in short wave infrared band. The result of platform impact analysis shows that when the rotation speed of the platform around the non-optical axis reaches 0.35 rad/s, or the rotation speed around the optical axis reaches 0.10 rad/s, or the vibration amplitude reaches about 5 μm, the SNR of the star map will decline to about 6 dB, which reaches the limit of star detection. The analysis of the influence of platform motion on image quality can provide theoretical support for the design and implementation of image stabilization algorithm for star sensors.