Broadband signal orientation estimation method based on conditional wave number spectral density

Abstract

The invention provides a broadband signal orientation estimation method based on conditional wave number spectral density. The method comprises the following steps: 1) receiving a broadband signal ofa long-distance target by using a space linear array, performing fast Fourier transform on the broadband signal in a time domain and a space domain to generate a space-time two-dimensional power spectral density function, and purifying an expanded conditional wave number spectral density spectrogram by taking a ratio of the space-time two-dimensional power spectral density to a frequency spectrumof array receiving response as conditional wave number spectral density to obtain a purified spectrum of a conditional wave number spectrum; and 2) selecting an estimated scanning azimuth angle on thepurified spectrum of the conditional wave number spectrum; calculating an intra-band peak energy position set corresponding to the estimated scanning azimuth angle; and correcting the estimated scanning azimuth angle through least square fitting to acquire a corrected azimuth angle, and taking the corrected azimuth angle and the corresponding peak energy as output so as to obtain an azimuth spectrogram, wherein the peak position on the azimuth spectrogram corresponds to an azimuth of a broadband signal. The method is high in azimuth estimation precision.

Description

technical field [0001] The invention belongs to the field of sonar digital signal processing, in particular to a method for estimating the direction of a broadband signal based on conditional wave number spectral density. Background technique [0002] Passive sonar detects targets and discriminates target types based on radiation noise. As one of the voiceprint characteristics of ships, broadband continuum describes the characteristics of ship radiation noise from the perspective of carrying energy in the frequency band. Detection has an integral role. The orientation estimation (Direction of Arrival, DOA) based on the sensor array is an important part of it, which faces problems such as limited array aperture, poor spatial resolution, and poor robustness to disturbance errors. [0003] At present, the algorithms for spatial direction finding of narrowband signals have become mature, but for wideband signals that carry more effective information and have higher application ...

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Problems solved by technology

[0007] The purpose of the present invention is to overcome the disadvantages of the existing high-resolution azimuth spectrum estimation algorithm, such as slow calculation speed, low feasibility, and the need to pre-estimate the number of sources and target azimuths in practical applications, the present invention proposes a Wideband Signal Direction Estimation Based on Conditional Wavenumber Spectral Density (CWSD-based) Method

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