A Filter-Based Correction Method for Hydrophone Received Signals

Abstract

The invention discloses a filter-based hydrophone receiving signal correction method, which comprises the following steps of performing interpolation according to the sensitivity value in the hydrophone factory report to obtain a hydrophone sensitivity curve after interpolation. Set the reference sensitivity of the hydrophone, and make a difference between the reference sensitivity and the interpolated hydrophone sensitivity curve to obtain the strength value that needs to be corrected at each frequency point. Computes the expected frequency response of the FIR filter, and computes the frequency response of the FIR filter design. The frequency response of the FIR filter design is approached to the expected frequency response of the FIR filter, and then the second-order cone programming method is used to design the FIR filter that meets the expected response, and finally the digital signal to be corrected is filtered and corrected using the designed FIR filter. The method has good real-time performance, strong practicability and high accuracy, and is applicable to correction of various signals such as single frequency / broadband.

Description

technical field [0001] The invention belongs to the technical field of underwater acoustic measurement, and in particular relates to a method for correcting a signal received by a hydrophone based on a filter. Background technique [0002] The hydrophone, also known as the receiving transducer, is used to receive the underwater acoustic signal and convert the acoustic signal into a voltage signal proportional to it. It is an indispensable equipment for underwater acoustic measurement. The sensitivity of the hydrophone characterizes the conversion ratio between the received sound pressure and the output voltage of the hydrophone. Due to the limited manufacturing process of hydrophones, there are certain differences in the sensitivity of hydrophones to different frequency signals, that is, there are certain fluctuations in the sensitivity of hydrophones at different frequencies. [0003] At present, most acoustic acquisition equipment performs piezoelectric conversion by sett...

AI Technical Summary

Problems solved by technology

Due to the limited manufacturing process of hydrophones, there are certain differences in the sensitivity of hydrophones to different frequency signals, that is, there are certain fluctuations in the sensitivity of hydrophones to different frequencies.

[0003] At present, most acoustic acquisition equipment performs piezoelectric conversion by setting a fixed reference sensitivity. Due to the difference between the actual sensitivity and the reference sensitivity, the measurement signal is deviated from the actual signal, and the received signal needs to be corrected according to the actual sensitivity curve.

[0004] The traditional hydrophone sensitivity correction is mainly based on the amplitude correction of a single frequency point, that is, directly multiply the received signal by the corresponding amplitude coefficient through the difference between the sensitivity of the frequency point and the reference sensitivity, this method cannot accurately correct the broadband signal

At present, most of the broadband signal correction methods for hydrophone reception are based on the frequency domain processing of Fourier transform. Since Fourier transform is a block processing method, it takes a certain amount of time to accumulate, and after inverse Fourier transform The data of each block in the subsequent time domain is discontinuous, and the phase information is distorted, making it impossible to recover accurate and continuous broadband time domain signals

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