红外与毫米波学报, 2020, 39 (6): 778, 网络出版: 2021-01-20
10 kHz重复率全天时卫星激光测距
卫星激光测距 10 kHz重复率 噪声测量 单光子探测 同步轨道 satellite laser ranging 10 kHz repetition rate noise measurement single photon detection synchronous orbit
摘要
在上海天文台1 kHz卫星激光测距系统上,通过885 nm端面泵浦Nd:YAG实现对激光器改进和升级;对泵浦电流、Nd:YAG冷却水温及再生放大建立周期加以控制,在10 kHz下获得6 W功率532 nm近等幅值皮秒激光脉冲输出,发散角0.6 mrad,脉宽30 ps,光束质量M2=1.2。测量与分析各重复率1 kHz、2 kHz、4 kHz、5 kHz、6.25 kHz、10 kHz下单光子探测器噪声水平、虚警概率与距离门控的关系,噪声光子数N与重复率f关系为![]()
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;重复率10 kHz下虚警探测概率P与距离门控Δt关系为![]()
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,获得的含噪声、测量频率与激光能量的激光回波数表达式对测距系统设计有一定指导作用。通过距离门控控制实现了10 kHz全天时卫星激光测距,并实现同步轨道3.6 x 104 km的北斗卫星Compassi6b白天测量。
Abstract
Based on the satellite laser ranging (SLR) system at Shanghai Astronomical Observatory, the laser output energy was increased by using the 885 nm end-pumped Nd:YAG amplification. Each pulse of 10 kHz was obtained near-equal amplitude by controlling the pump gain current, Nd:YAG crystal cool water temperature and building time of regeneration amplification. An average power of 6 W picosecond laser in a wavelength of 532 nm was obtained at a repetition rate of 10 kHz with the divergence angle of 0.6 mrad, pulse width of 30 ps, a beam quality M2 of 1.2. The noise levels for single photon detector at each repetition rate of 1 kHz, 2 kHz, 4 kHz, 5 kHz, 6.25 kHz, and 10 kHz was measured and analyzed respectively. The relationship between the false alarm probability and the ranging gating is obtained. The relationship between the number (N) of noise photons and the repetition rate (f) is ![]()
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, and the relationship between the false alarm detection probability (P) and the ranging gated (Δt) at the repetition rate of 10 kHz is ![]()
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, and also the function of the number of laser echoes with noise, laser energy and repetition are obtained, which is beneficial to design the SLR system. Therefore, it realizes the satellite laser ranging in all day, and the farthest distance was to the synchronous orbit of Beidou Compassi6b satellite.
龙明亮, 张海峰, 门琳琳, 吴志波, 邓华荣, 秦思, 张忠萍. 10 kHz重复率全天时卫星激光测距[J]. 红外与毫米波学报, 2020, 39(6): 778. Ming-Liang LONG, Hai-Feng ZHANG, Lin-Lin MEN, Zhi-Bo WU, Hua-Rong DENG, Si QIN, Zhong-Ping ZHANG.