Target orientation and distance combined sparse reconstruction positioning method based on seabed horizontal L-shaped array

Abstract

The invention relates to a target orientation and distance combined sparse reconstruction positioning method based on a seabed horizontal L-shaped array. The method comprises the following steps: laying a horizontal L-shaped array at the seabed, receiving sound signals emitted by multiple targets near the sea surface, and obtaining a source matrix of the multiple targets; in the azimuth and distance two-dimensional plane of the target, obtaining a sparse source matrix about the target; obtaining a sparse array matrix about N-element L-shaped array receiving signals; reconstructing a sparse signal by using the obtained sparse array matrix and the normalized sparse source matrix; adopting a norm regularization method to carry out optimal solution on the reconstructed sparse signals; and determining the orientation and distance information of the target according to the spectral peak position and intensity of the spatial spectrum, and judging the relative size of the target power. According to the method, the influence of multipath interference on the target azimuth-distance joint estimation precision can be effectively stripped and reduced, the target positioning result without spatial ambiguity is obtained, and the position information and the relative intensity of multiple targets can be accurately obtained at the same time.

Description

technical field [0001] The invention relates to the technical field of seabed signal positioning and detection, and relates to a positioning method based on the joint sparse reconstruction of target azimuth and distance of a seabed horizontal L-shaped array. Background technique [0002] In the shallow sea environment, the acoustic channel includes the sea surface and the bottom of the sea, and there is an obvious multi-path effect in sound propagation. Multi-path acoustic signals are one of the most important interferences for shallow sea target azimuth estimation and positioning. For the acoustic positioning of short-range targets in shallow seas, the existence of the multi-path effect will cause a large number of false "false peaks" in the positioning spectrum, making it impossible to accurately determine the position of the real target. It may affect the judgment of the location of the real "weak target", leading to serious errors in the results of multi-target discrimin...

AI Technical Summary

Problems solved by technology

For the acoustic positioning of short-range targets in shallow seas, the existence of multi-path effects will cause a large number of false "false peaks" in the positioning spectrum, making it impossible to accurately determine the position of the real target. It may affect the judgment of the location of the real "weak target", leading to serious errors in the multi-target discrimination results

[0003] In addition, signal processors such as conventional CBF and MVDR are not capable of distinguishing coherent targets of the same frequency. Conventional CBF processors can be applied to coherent targets, but the spatial resolution is not high enough to distinguish targets at relatively short spatial distances. Although the MVDR processor can improve the resolution, it cannot be directly applied to coherent sound sources (Luo Fangfang, Sheng Xueli, Mei Jidan, Guo Yong. Research on time-reverse positioning technology based on MVDR high-resolution algorithm. Journal of Harbin Engineering University , 2010,31(7): 945-950), so that the above two methods are greatly limited in practical application

[0004] Patent ZL201210162659.8 is applicable to the underwater noise source focusing and positioning method with high robustness in shallow sea multi-channel environment. Aiming at the signal processing problem in shallow sea environment, the idea of ​​sonar passive positioning based on model matching has obtained certain suppression of multi-channel signals effect, but due to the use of a linear array, its disadvantage is that it cannot guarantee the "no fuzzy" positioning of the entire space on the target azimuth

In terms of focusing and locating noise sources in shallow seas, studies on the influence of multi-path effects in shallow seas and feasible methods generally focus on the time-reversal mirror method (Hui Juan, Hu Dan, Hui Junying, etc. Research on the Principle of Focused Beamforming Acoustic Image Measurement. Acoustics Journal, 2007, 32(4): 356-361), there is still no positioning method using sparse signal reconstruction to obtain high-precision bearing-distance joint estimation

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