阵列探测技术在激光测距中的应用

Application of array detection technology in laser ranging

高精度的空间碎片观测数据对航天器碰撞预警具有重要意义,激光测距技术是目前空间目标距离测量中精度最高的一种技术,但大多数空间碎片上并未携带角反射器装置,激光测距回波信号较弱。阵列探测技术可以提高回波信号较弱的空间碎片激光测距探测成功概率,中国科学院云南天文台2015年开始开展基于阵列探测技术的激光测距试验,2017年成功将阵列超导纳米线单光子探测器和多通道事件计时器等阵列探测技术应用于激光测距试验系统中,分别在2017年3月和2018年3月的激光测距试验中,成功采集2×2和4×4阵列激光测距数据。其中探测到最小目标为轨道高度约1 000 km、大小为雷达截面(Radar Cross Section,RCS) 0.045 m^2的空间碎片;探测到最远目标为斜距约5 000 km、大小为RCS 18.25 m^2的空间碎片。

High-precision space debris observation data is of great significance for spacecraft collision early warning. Laser ranging technology is the most accurate technology in space target distance measurement at present, but there is no angle reflector device on most of space debris, and the echo signal of space debris laser ranging is weak. Array detection technology can improve the success probability of space debris laser ranging detection with weak echo signal. Yunnan Observatory of Chinese Academy of Sciences started to carry out space debris laser ranging test based on array detection technology in 2015, and successfully applied array detection technology such as array superconducting nanowire single photon detector and multi-channel event timer to laser ranging test system in 2017, 2×2 array laser ranging data were successfully collected in the space debris laser ranging test in March 2017, and 4×4 array laser ranging data were successfully collected in the space debris laser ranging test in March 2018. Among them, the minimum target detected was the space debris with orbit height of about 1 000 km and size of Radar Cross Section(RCS) 0.045 m^2;the farthest target detected was the space debris with oblique distance of about 5 000 km and size of RCS 18.25 m^2.