Infrared Methods for Daytime Detection of Space Target

In order to solve the problem that ground-based optical telescope cannot detect space targets in the daytime, an infrared detection method is proposed in this paper. Firstly, from the perspective of spectral characteristics of space targets and skylight, the short-wave infrared band(SWIR) of 0.9 similar to 1.7 mu m is optimized, which reduces the brightness of the skylight, and avoids the cooling of the optical system. Secondly, the signal-to-noise ratio(SNR) of the target is improved by the time-domain multi-frame accumulation algorithm and the goal of daytime 'extended range' detection of optical telescope is achieved. Experiments on a 0.3-meter telescope show that the space targets, which SNR less than 1 are detected by adopting this method in the daytime, when the zenith angle of sun is 40 degrees, exposure time is 40ms, and the number of the cumulative frames is 360, the limit detection ability is 10.8m(V). The results of the experiments well verify the theoretical analysis, which provides a reference for the system design of the next generation of ground-based optical telescope.