Huo Li, Wu Zhiyong, Wu Jiabin, Gao Shijie, Chen Yunshan, Song Yinuo, Wang Shuaifei
Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Sensors (Basel). 2022 Apr 18;22(8):3092. doi: 10.3390/s22083092.
In atmospheric laser communication, a beam is transmitted through an atmospheric channel, and the photocurrent output from a quadrant detector (QD) used as the tracking sensor fluctuates significantly. To ensure uninterrupted communication and to adapt to such fluctuations, in this paper we apply logarithmic amplifiers to process the output signals of a QD. To further improve the measurement accuracy of the spot position, we firstly propose an integral infinite log-ratio algorithm (IILRA) and an integral infinity log-ratio algorithm based on the signal-to-noise ratio (BSNR-IILRA) through analysis of the factors influencing the measurement error considering the signal-to-noise ratio (SNR) parameter. Secondly, the measurement error of the two algorithms under different SNRs and their variations are analyzed. Finally, a spot position detection experiment platform is built to correctly and efficiently verify the two algorithms. The experimental results show that when the SNR is 54.10 dB, the maximum error and root mean square error of the spot position of the IILRA are 0.0054 mm and 0.0039 mm, respectively, which are less than half those of the center approximation algorithm (CAA). When the SNR is 23.88 dB, the maximum error and root mean square error of the spot position of the BSNR-IILRA are 0.0046 mm and 0.0034 mm, respectively, which are one-thirtieth and one-twentieth of the CAA, respectively. The spot position measurement accuracy of the two proposed algorithms is significantly improved compared with the CAA.
在大气激光通信中，光束通过大气信道传输，用作跟踪传感器的象限探测器（QD）输出的光电流会发生显著波动。为确保通信不间断并适应这种波动，本文应用对数放大器来处理QD的输出信号。为进一步提高光斑位置的测量精度，我们首先通过分析考虑信噪比（SNR）参数的影响测量误差的因素，提出了积分无限对数比算法（IILRA）和基于信噪比的积分无限对数比算法（BSNR-IILRA）。其次，分析了这两种算法在不同信噪比下的测量误差及其变化情况。最后，搭建了光斑位置检测实验平台，对这两种算法进行了正确有效的验证。实验结果表明，当SNR为54.10 dB时，IILRA光斑位置的最大误差和均方根误差分别为0.0054 mm和0.0039 mm，均小于中心近似算法（CAA）的一半。当SNR为23.88 dB时，BSNR-IILRA光斑位置的最大误差和均方根误差分别为0.0046 mm和0.0034 mm，分别是CAA的三十分之一和二十分之一。与CAA相比，所提出的两种算法的光斑位置测量精度有显著提高。
