High-Precision Log-Ratio Spot Position Detection Algorithm with a Quadrant Detector under Different SNR Environments

Abstract

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.

Research on Manufacturing Equipment Operation State Evaluation Technology Based on Fractional Calculus

“…up to now, there have been many research results Common mathematical algorithms are fuzzy set theory [22], fuzzy neural networks [23], probability model [24] and particle swarm optimization algorithm [25], et al and obtained a regrettable research review. For example, Huo et al [26] proposed an integral infinite log-ratio algorithm (IILRA) and an integral infinity log-ratio algorithm based on signal-to-noise ratio (BSNR-IILRA) to improve the detection accuracy of the laser communication detection position in the atmosphere. Zhiyuan et al [27] proposed a normalizedvariance-detection method based on compression sensing measurements of received signals and solved the problem of fast and accurate spectrum sensing technology under the condition of a low signal-to-noise ratio.…”

“…In terms of the mathematical properties of the signal and the characteristics of the signal structure, the detection signal contains information on the fractional differential charac-teristics; however, this type of information is not suitable for processing by integer differential operators. For years, many mathematicians and scientists have attempted to apply fractional calculus theory in signal processing and have achieved good application effects [40,41]. It is assumed that there is a detection signal ( )…”

High Accuracy Detection Technique for Information Data Under the Influence of Multiple Factors based on Fractional Partial Differential Equations

“…From the analysis of the amplitude frequency characteristics of fractional differential operators, we can know that in the signal enhancement stage, when the influencing factors reach a certain value, the fractional differential operator can fuse the differences between the detection data caused by the influencing factor effectively, so, the fractional calculus is used to describe many phenomena in engineering and science [13,14]. The fractional differential equations have been used enormously for last two decades because of their varied applications in many spheres of physical and biological sciences [15][16][17], but it can only be applied to processing one-dimensional signal.…”

“…up to now, there have been many research results Common mathematical algorithms are fuzzy set theory [9], fuzzy neural networks [10], probability model [11] and particle swarm optimization algorithm [12], et al and obtained a regrettable research review. For example, Li Huo et al [13] proposed an integral infinite log-ratio algorithm (IILRA) and an integral infinity log-ratio algorithm based on the signal-to-noise ratio (BSNR-IILRA) to Improve the detection accuracy of laser communication detection position in the atmosphere. Shen Zhiyuan et al [14] proposed a normalized-variance-detection method based on compression sensing measurements of received signal, and solved the problem of fast and accurate spectrum sensing technology under the condition of low signal-to-noise ratio.…”

Research on Manufacturing Equipment Operation State Evaluation Technology Based on Fractional Calculus

“…Common mathematical algorithms are fuzzy set theory [ 23 ], fuzzy neural networks [ 24 ], the probability model [ 25 ], and the particle swarm optimization algorithm [ 26 ]. For example, Huo et al [ 27 ] proposed an integral infinite log-ratio algorithm (IILRA) and an integral infinity log-ratio algorithm based on signal-to-noise ratio (BSNR-IILRA) to improve the detection accuracy of the laser communication detection position in the atmosphere. Zhiyuan et al [ 28 ] proposed a normalized-variance detection method based on compression sensing measurements of received signals and solved the problem of fast and accurate spectrum sensing technology under the condition of a low signal-to-noise ratio.…”