Delay inequality estimation method with unknown frequency

A time delay difference and frequency technology, which is applied in the field of time delay difference estimation with unknown frequency, can solve the problem that the time delay difference estimation of the target radiation signal of the underwater acoustic positioning system cannot be well realized.

Inactive Publication Date: 2014-09-17
INST OF ACOUSTICS CHINESE ACAD OF SCI
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Problems solved by technology

[0005] The purpose of the present invention is to overcome the problem of the time delay difference estimation of receiving target radiation signals between array elements in the underwater acoustic positioning system t

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  • Delay inequality estimation method with unknown frequency
  • Delay inequality estimation method with unknown frequency
  • Delay inequality estimation method with unknown frequency

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Embodiment Construction

[0047] The present invention will be further described below in conjunction with the accompanying drawings.

[0048] Fig. 1(a) is a positioning system virtual device based on the algorithm of the present invention provided by the present invention, and the part included in the dotted line is the position of the present invention in the existing underwater target positioning system.

[0049] The present invention provides a method for estimating time delay difference of unknown frequency, comprising:

[0050] Step 1), taking array elements 1 and 2 as an example, the time domain signal x received by array elements 1 and 2 1 (t) and x 2 (t) Perform Fourier transform to get x 1 (t) and x 2 (t) The corresponding frequency domain signal X 1 (f) and X 2 (f); then, for X 1 (f) and Multiply to get the frequency domain cross-spectrum data RX of array elements 1 and 2 12 (f), the specific calculation formula is:

[0051] X ...

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Abstract

The invention relates to a delay inequality estimation method with unknown frequency, wherein the method is used for estimating the delay inequality of target radiation signal reception by different receiving array elements in an acoustic positioning system. The method comprises the following steps: calculating and getting a time domain correlation spectrum and corresponding initial delay inequality of each frequency unit several times; calculating and obtaining an initial delay inequality variance corresponding to each frequency unit and carrying out reciprocal on the initial delay inequality variance to form a weighing factor; multiplying an average time domain correlation spectrum corresponding to each frequency unit by the corresponding weighing factor and obtaining a final time domain correlation spectrum by accumulation, and then calculating final delay inequality. According to the invention, on the basis of maximum value random of the noise-frequency unit cross-correlation spectrum and the characteristic of basic consistency of maximum values of the target- frequency unit cross-correlation spectrum, statistics is carried out on the delay inequality estimation results of all frequency units, thereby highlighting the proportion of the line spectrum signal in delay inequality estimation and weakening the proportion of the noise unit in delay inequality estimation.

Description

technical field [0001] The invention relates to the field of sonar signal processing, in particular to a time delay difference estimation method with unknown frequency. Background technique [0002] Because active sonar is easy to expose, passive sonar is often used to detect underwater targets. With the continuous improvement of vibration reduction and noise reduction technology, the target radiation noise is continuously reduced compared with the environmental noise, resulting in the continuous reduction of the prior knowledge that sonar equipment can provide for its received signals. The signal detection method based on broadband energy integration can no longer meet the detection requirements of underwater remote targets in passive sonar detection. [0003] Studies have shown that the rotation of the propeller of the underwater target will cut the water body to generate low-frequency signals, part of which will directly appear in the target radiation signal in an additi...

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Application Information

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IPC IPC(8): G01S7/52
CPCG01S5/22
Inventor 郑恩明陈新华孙长瑜
Owner INST OF ACOUSTICS CHINESE ACAD OF SCI
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