以上海天文台收发分离的21 cm/60 cm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400 ps。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2.5 km的双望远镜系统对距离大于1000 km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.