低照度空间目标激光主动增亮技术实验研究

Experimental Study on Technology of Laser Active Illumination to Dim Light Space Targets

空间目标观测中，目标亮度直接影响着其跟踪能力及定位精度。激光技术作为主动测量技术，通过地面激光跟踪与测量系统向低照度空间目标主动发射激光，望远镜及CCD相机在接收目标反射的太阳光的同时亦接收激光信号，可提高目标星象在CCD上的亮度，有利于目标跟踪和测量。采用532 nm波长低功率激光作为地面光源，对带激光反射器卫星开展了激光主动增亮实验，验证技术方法可行性。根据太阳光谱辐照度理论、地面测量系统参数、激光测距雷达方程等，分析了激光主动增亮卫星前后视星等。利用星象灰度对比法，获得了实验中所测量卫星增亮前后视星等，并与理论计算结果进行了比较，验证了理论与实验方法的合理性，为进一步开展激光主动增亮技术的研究与应用奠定了基础。

For the observation of space targets orbiting the earth, the intensity of brightness of space targets will influence the detection ability and position accuracy. Laser technology, as one of the active measurement techniques, has been commonly adopted in the ground based tracking and measuring system. Through transmitting laser signal to space targets with low brightness, the receiving telescope and CCD camera on ground receive and detect the laser echoes as well as sunlight reflected from targets to make the image of space targets displayed on CCD camera more brighter, which will help to track and measure space targets. The laser signal with 532 nm wavelength and low power is adopted as the light source, and the observation of laser active illumination to dim light artificial satellites equipped with retro-reflectors is successfully implemented to validate the feasibility of the proposed measurement technology. According to the theory of solar spectrum radiation, the parameters of laser track and observation system on ground and laser measurement ladar link equation, the visual magnitude of fore-and-aft laser active illumination to space targets is analyzed in theory. Based on the image processing method of gray correlation, the measured visual magnitude of fore-and-aft laser active illumination to space targets is obtained and compared to the results of theoretical calculation to verify the rationality of theoretical and experimental method. Experimental results have laid the foundation for its further application to space targets.