Analysis of SNR for ground-based infrared detection of space object

A simulation model for sky background radiation, atmosphere transmission, and ground-based sensor was proposed. Based on the proposed model and the existing model for studying the infrared radiometric feature of a LEO satellite, a proposal for investigating the infrared detection of space object was put forward. The proposal was used to calculate the signal-to-noise ratio (SNR) of the sensor received from a modeling satellite, thereby the detection effect of satellite at different transit time was analyzed. The method to choose the best observation band in different case was advanced by comparing the character of SNR on various IR bands. It can be concluded from the results that the SNR on the near infrared band is very high when the ground sensor is in the earth's shadow and the object is sunlit. No signal is detected in the sensor when the object is in the earth's shadow. In the far infrared band, the object can be always detected either it is sunlit or in the earth's shadow. However, the SNR gets smaller when the surface temperature of the satellite is lower or the range of detection is larger. In addition, due to the sun-oriented character of the battery panels, the signal detected by the sensor varies with the solar elevation angle.