A method for differential enhancement of deep weak signals of geological radar

Abstract

The present invention provides a method for differential enhancement of deep weak signals of geological radar. The method performs boundary extension on two-dimensional rectangular profile data of geological radar, obtains radar background noise by extracting high-frequency components of geological radar data of adjacent channels, and then offsets the background noise by weighted average to obtain a geological radar profile after deep weak signal enhancement. The enhanced deep information is richer, which is beneficial to improving the detection capability of geological radar for deep targets.

Description

Technical Field

[0001] The present invention belongs to the field of geophysical detection, and specifically is a method for differentially enhancing deep weak signals of geological radar. The method extracts high-frequency components of geological radar data from adjacent channels to obtain radar background noise, and then offsets the background noise by weighted average to obtain a geological radar profile after deep weak signal enhancement. The enhanced deep information is richer, which is beneficial to improving the geological radar's detection capability for deep targets. Background Art

[0002] During coal mining, geological structural changes are easily triggered, and hidden geological structural anomalies (such as faults, collapse columns, folds, etc.) are very likely to cause mining accidents. Major mining accidents include roof damage, coal and gas outbursts, and mine water inrush. Geological radar, as an effective geophysical exploration method, is suitable for detecting geological structural anomalies such as faults, collapse columns, and folds.

[0003] The geological radar sends high-frequency broadband electromagnetic waves in the form of pulses to the working face. A part of the electromagnetic waves directly reaches the receiving antenna through the transmitting antenna to form a coupled wave. After being transmitted by the transmitting antenna, it encounters the interface between the air and the road surface and does not enter the underground but is directly reflected back and received by the receiving antenna, forming a direct wave. The coupled wave and the direct wave are often collectively referred to as direct coupled waves, which are often used to determine the time zero point as a reference for the depth of the underground target body. The other part of the electromagnetic wave enters the front of the working face and propagates in the medium. When encountering a target body with different electrical properties (such as faults, collapse columns, folds, etc.) or a different medium interface, the electromagnetic wave is reflected. When the reflected electromagnetic wave returns to the working face, it is received by the receiving antenna. After being collected, processed, and stored, the received signal becomes the geological radar data containing the medium information in front of the working face.

[0004] During the geological radar detection process, the deep signal is seriously disturbed by the surrounding space environment and complex geological environment. Therefore, by extracting the high-frequency components of the adjacent geological radar data, the radar background noise is obtained, and then the background noise is offset by weighted average to obtain the geological radar profile after the deep weak signal is enhanced. The enhanced deep information is richer, which is conducive to improving the geological radar's detection capability for deep targets. Summary of the invention

[0005] The purpose of the present invention is to obtain the radar background noise by extracting the high-frequency components of the adjacent geological radar data according to the characteristics of geological radar data, and then to offset the background noise by weighted average to obtain the geological radar profile after the deep weak signal is enhanced.

[0006] The specific steps of this method are as follows:

[0007] Step 1: For the two-dimensional profile D(x,y) of the geological radar, where x = 1, 2, ..., n, y = 1, 2, ..., m, perform boundary extension to obtain

[0008]

[0009] Where y′=1,2,...,m,m+1,...,m+N, usually N=1;

[0010] Step 2: Extended 2D geological radar profile Take two adjacent data and calculate the difference

[0011]

[0012] Where x = 1, 2, ..., n, y = 1, 2, ..., m, is the geological radar differential profile, which is obtained through one-dimensional Fourier transform.

[0013]

[0014] After taking the high-frequency component of the geological radar spectrum profile E(ω,y), we get E(ω′,y), where After one-dimensional inverse Fourier transform, we get

[0015]

[0016] in Differential profile High frequency noise profile;

[0017] Step 3: Geological radar two-dimensional profile D(x,y) and high-frequency noise profile Weighted average is used to calculate the geological radar profile after the deep weak signal is enhanced, and the

[0018]

[0019] in is the enhanced geological radar profile, and α and β are weight coefficients.

[0020] The present invention has the following advantages:

[0021] 1. The background noise of the geological radar can be obtained by the method for extracting high-frequency components of adjacent-channel geological radar data proposed in the present invention.

[0022] 2. The method for differential enhancement of deep weak signals of geological radar proposed in the present invention can offset the background noise and obtain the geological radar profile after deep weak signal enhancement, which is beneficial to improving the detection capability of geological radar for deep targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Flow chart of geological radar data processing of the present invention

[0024] Figure 2 Initial profile of geological radar data of the present invention

[0025] Figure 3 Geological radar data enhanced profile of the present invention DETAILED DESCRIPTION

[0026] Aiming at the fact that adjacent channels of geological radar data are highly correlated, the present invention obtains the radar background noise by extracting the high-frequency components of the adjacent channel geological radar data, and then offsets the background noise by weighted averaging to obtain the geological radar profile after the deep weak signal is enhanced. The enhanced deep information is richer, which is beneficial to improving the detection capability of the geological radar for deep targets.

[0027] The present invention provides a method for differential enhancement of deep weak signals of geological radar, which can be divided into two situations. In the first situation, most of the background noise can be offset by weighted averaging. The specific steps are as follows:

[0028] (1) For the two-dimensional geological radar profile D(x,y), where x = 1, 2, ..., n, y = 1, 2, ..., m, the boundary is extended to obtain

[0029]

[0030] Where y′=1,2,...,m,m+1,...,m+N, usually N=1;

[0031] (2) Extended 2D geological radar profile Take two adjacent data and calculate the difference

[0032]

[0033] Where x = 1, 2, ..., n, y = 1, 2, ..., m, is the geological radar differential profile, which is obtained through one-dimensional Fourier transform.

[0034]

[0035] After taking the high-frequency component of the geological radar spectrum profile E(ω,y), we get E(ω′,y), where After one-dimensional inverse Fourier transform, we get

[0036]

[0037] in Differential profile High frequency noise profile;

[0038] (3) Geological radar two-dimensional profile D(x,y) and high-frequency noise profile Weighted average is used to calculate the geological radar profile after the deep weak signal is enhanced, and the

[0039]

[0040] in is the enhanced geological radar profile, and α and β are weight coefficients.

[0041] In the second case, the high frequency noise is weighted averaged It is difficult to offset most of the background noise. In this case, the high-frequency noise of the adjacent channels can be weighted averaged. and The specific steps are as follows:

[0042] (1) For the two-dimensional geological radar profile D(x,y), where x = 1, 2, ..., n, y = 1, 2, ..., m, the boundary is extended to obtain

[0043]

[0044] Where y′=1,2,...,m,m+1,...,m+N, usually N=1;

[0045] (2) Extended 2D geological radar profile Take two adjacent data and calculate the difference

[0046]

[0047] Where x = 1, 2, ..., n, y = 1, 2, ..., m, is the geological radar differential profile, which is obtained through one-dimensional Fourier transform.

[0048]

[0049] After taking the high-frequency component of the geological radar spectrum profile E(ω,y), we get E(ω′,y), where After one-dimensional inverse Fourier transform, we get

[0050]

[0051] in Differential profile High frequency noise profile;

[0052] (3) Geological radar two-dimensional profile D(x,y) and high-frequency noise profile Weighted average is used to calculate the geological radar profile after the deep weak signal is enhanced, and the

[0053]

[0054] in is the enhanced geological radar profile, α, β, γ, ρ is the weight coefficient.

Claims

1. A method for differential enhancement of deep weak signals of geological radar. The method is based on the two-dimensional profile of geological radar. The radar background noise is obtained by extracting the high-frequency components of the geological radar data of adjacent channels. The background noise is then offset by weighted average to obtain the geological radar profile after the deep weak signal is enhanced. The specific steps are as follows: Step 1: For the two-dimensional profile D(x,y) of the geological radar, where x = 1, 2, ..., n, y = 1, 2, ..., m, perform boundary extension to obtain Where y′=1,2,...,m,m+1,...,m+N, usually N=1; Step 2: Extended 2D geological radar profile Take two adjacent data and calculate the difference in, x=1,2,...,n, y=1,2,...,m, is the geological radar differential profile, which is obtained through one-dimensional Fourier transform. After taking the high-frequency component of the geological radar spectrum profile E(ω,y), we get E(ω′,y), where After one-dimensional inverse Fourier transform, we get in Differential profile High frequency noise profile; Step 3: Geological radar two-dimensional profile D(x,y) and high-frequency noise profile Weighted average is used to calculate the geological radar profile after the deep weak signal is enhanced, and the in is the enhanced geological radar profile, and α and β are weight coefficients.

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