距离千米级双望远镜的空间碎片激光测距

Laser Ranging for Space Debris Using Double Telescopes with Kilometer-Level Distance

以上海天文台收发分离的21cm/60cm口径卫星激光测距系统为例,利用高精度计时器、光电探测器等设备,对发射/接收系统的时延分别进行测量与标定,测量地面靶目标所得到的发射/接收系统的总时延与常规地面靶目标测量方法的测量均值相比,时延标定误差为400ps。在此基础上,利用高精度时钟系统,并在解决远距离望远镜回波信号探测距离门控制问题的条件下,实现了相距2.5km的双望远镜系统对距离大于1000km的空间碎片目标的测量,验证了远距离接收空间碎片目标激光回波信号的能力。

In this paper,using high-precision timers,photoelectric detectors,and other equipment,the laser transmitting and receiving system delays for a 60-cm receiving telescope aperture system at the Shanghai Observatory are measured and calibrated,with a transmitting telescope aperture of 21 cm.By comparing the result of a target measurement by a space debris laser ranging(SDLR)system on the ground with the measured results of the conventional target measurement,we find that the calibration error of delay is approximately 400 ps.On this basis,using a high-precision clock system in a laser ranging system,SDLR is achieved for the first time in China using a single telescope to send laser pulses and double telescopes with a distance of 2.5 km to receive laser echoes,solving the problem of detection range gate control of echo signals from the remote telescope.This system realizes a range distance of over 1000 km.The proposed method demonstrates the ability to receive laser echoes from space debris from a remote distance on the ground with multiple telescopes.