Chirp Sub-Bottom Profiler Signal Processing for Waveform Distortion

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Solution Overview

Problem

Chirp sub-bottom profilers face challenges in processing high-frequency signals due to significant waveform distortion and noise, which complicates the extraction of quantitative physical property information from sub-bottom data.

Innovation Solution

A signal processing method that involves transmitting and correcting chirplet signals, generating a comparison chirplet using sub-bottom reflection signals, cross-correlating and auto-correlating to produce Klauder wavelets, and deconvoluting these wavelets to derive physical properties of the survey target strata, thereby minimizing waveform distortion and obtaining quantitative information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-frequency signals are used in chirp sub-bottom profiler, then resolution of data is improved, but waveform distortion and noise increase significantly

Engineering Contradiction:

Improveresolution of dataVSAvoidwaveform distortion and noise

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent transforms the chirp signal parameters through cross-correlation with a comparison chirplet, converting the distorted high-frequency signal into a Klauder wavelet with optimized frequency-time characteristics. This parameter transformation resolves the waveform distortion while preserving the high-frequency resolution benefits

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The comparison chirplet serves as an intermediary reference signal that mediates between the transmitted chirp signal and the received distorted signal. By cross-correlating the received signal with this intermediary, the system extracts accurate subsurface information while eliminating the harmful waveform distortion effects

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If conventional envelope conversion method is used to process chirp data, then processing complexity is reduced, but quantitative physical property information is lost

Engineering Contradiction:

Improvedata processing complexityVSAvoidquantitative physical property information

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The patent replaces the conventional envelope detection mechanism with a wavelet-based deconvolution approach. Instead of simply converting to envelope form, the system uses Klauder wavelets and spectral deconvolution to extract quantitative physical properties while maintaining processing feasibility through systematic mathematical operations

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If multi-frequency sound source is used in chirp sub-bottom profiler, then ability to grasp high and low frequency bands simultaneously is improved, but signal processing difficulty increases

Engineering Contradiction:

Improvefrequency band coverageVSAvoidsignal processing difficulty

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the multi-frequency chirp signal processing into distinct stages: cross-correlation with comparison chirplet to generate Klauder wavelets, spectral analysis to obtain amplitude spectra, and deconvolution to extract physical properties. This segmentation makes the complex multi-frequency processing manageable and systematic

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method effectively reduces waveform distortion and noise, allowing for the accurate derivation of physical properties such as reflection coefficients and impedance from sub-bottom data, enhancing the reliability of sub-bottom exploration results.

Implementation Method 1

transmitting a chirplet to survey target strata using a chirp sub-bottom profiler and acquiring raw data reflected and received from a target object

Methodology Applied

Scientific EffectAcoustic reflection: Reflection

Implementation Method 2

cross-correlating the corrected raw data with the comparison chirplet to generate a first Klauder wavelet section

Methodology Applied

Scientific EffectCross-correlation:

Implementation Method 3

auto-correlating the comparison chirplet to generate a second Klauder wavelet

Methodology Applied

Scientific EffectAuto-correlation:

Implementation Method 4

deriving a physical property of the survey target strata by deconvoluting the first Klauder wavelet section and the second Klauder wavelet

Methodology Applied

Scientific EffectDeconvolution:

Data Source

PatentUS10488514B2Signal processing method of raw data obtained by using chirp sub-bottom profiler and readable storage medium storing the method

Publication Date: 2019.11.26 UNIHUB INC

AI summary

Provided is method of signal processing of raw data obtained using a chirp sub-bottom profiler. The method includes transmitting a chirplet (minimum frequency: initial first frequency, maximum frequency: initial second frequency, pulse length: initial pulse length) to survey target strata using a chirp sub-bottom profiler and acquiring raw data reflected and received from a target object, correcting the raw data, generating a comparison chirplet using a sub-bottom reflection signal of the raw data, cross-correlating the corrected raw data with the comparison chirplet to generate a first Klauder wavelet section, auto-correlating the comparison chirplet to generate a second Klauder wavelet, and deriving a physical property of the survey target strata by deconvoluting the first Klauder wavelet section and the second Klauder wavelet.