Simulation of earth background radiation characteristic for satellite borne laser warning system

The earth background radiation is a kind of main background interference for satellite borne laser warning system in the space environment, and it is so necessary that the radiation characteristic be studied. In this paper, the mathematic model of the earth background radiation is established, the input parameters of 6S model are analyzed and set, and the simulation of earth background radiation is carried on aiming at the alarm wavelength 1.315 μm and the waveband 0.9-1.7 μm which is the responsive bandwidth of the detector. The results show that: with the increase of zenith angle, the irradiance from ground reflection increases, but the irradiances of atmospheric path radiation and surface-atmosphere interaction at the satellite level decrease; comparing with other two parts, the irradiance from ground reflection weighs most, and the corresponding percentages for 1.315 μm and 0.9-1.7 μm are 75.89% and 73.99%, respectively. The total irradiance at the satellite level from earth background radiation has exceeded the detection sensitivity of the system (about 1 mW/cm²), which may arouse the false alarm. So, the special technique of background suppression must be studied.