Ground penetrating radar zero offset correction method

Abstract

The invention discloses a ground penetrating radar zero offset correction method. The method comprises the following steps: S1, acquiring radar data # imgabs0 # matrix B; s2, traversing the matrix B according to columns, taking a column of data # imgabs1 #, and calculating the size of a sliding window; s3, calculating the sum of # imgabs2 data points in the window; s4, traversing all data points in # imgabs3 #, calculating the value of each data point after zero offset correction, and updating the sliding window; s5, subtracting the moving average value from the original data to perform zero offset correction, and updating the calculated value to # imgabs4 #; and S6, repeating the steps S2-S5, and circularly updating the values in the whole matrix B. The size of a sliding window is adjusted based on the sampling rate, frequency, time window and other parameters of radar signals, so that the range of smoothing operation is controlled, zero offset correction is dynamically calculated, it is ensured that the signals can be effectively smoothed and noise can be effectively removed during zero offset correction, and meanwhile effective information of the signals is kept; particularly, under the condition that the signal change is large or much noise exists, a more accurate and stable correction effect can be provided.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and particularly to a zero-offset correction method for ground penetrating radar. Background Art

[0002] Ground Penetrating Radar (GPR) is a non-destructive testing technology mainly used to detect underground objects, structures or layered geology. GPR emits high-frequency electromagnetic waves (usually microwaves or ultra-high frequencies) into the ground. When the electromagnetic waves encounter the boundary of different media, reflection or refraction phenomena will occur. These reflected signals are received and analyzed to obtain an image or information of the underground structure. With the development of computer technology and digital signal processing technology, GPR has made great progress in data acquisition, processing and interpretation. Modern GPR systems usually have higher acquisition speeds, stronger signal processing capabilities and better image quality, and can more effectively handle complex underground detection tasks. Ground Penetrating Radar has become one of the indispensable tools in the fields of geological survey, construction engineering, archaeological exploration, etc.

[0003] Zero-offset correction is a very important step in GPR data processing. The purpose is to eliminate or reduce the baseline drift caused by equipment errors or environmental factors during the instrument measurement process, ensure the accuracy and reliability of the data, ensure that the detected signal is consistent with the reflection signal of the actual underground object, and avoid errors caused by equipment or signal noise.

[0004] There are several existing correction methods: Baseline correction is the most common zero-offset correction method. By analyzing the background signal without targets or reflections, the DC offset in the signal is removed. Generally, this correction is performed after data acquisition. The correction process restores the original form of the signal by removing the DC component of the signal or filtering; The time-domain correction method mainly corrects the offset by adjusting the acquisition time of the signal. A common practice is to correct the time difference between the received signal and the transmitted signal to remove the time deviation caused by the equipment; Real-time filtering is to perform high-pass or low-pass filtering on the signal in real time to remove background noise or low-frequency interference; Digital signal processing uses digital signal processing technology to dynamically adjust the collected signal to eliminate zero offset. These above methods have low stability, are sensitive to noise, and cannot well retain the characteristics of the signal. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a zero-offset correction method for ground penetrating radar.

[0006] The purpose of the present invention is achieved by the following technical solutions: A zero-offset correction method for ground penetrating radar, comprising the following steps:

[0007] S1: Collect radar data Matrix B, the size of matrix B is ;

[0008] S2: Traverse matrix B column by column, and take a column of data , is matrix, is the th column of data, calculate the size of the sliding window .

[0009] ;

[0010] Among them, is the number of radar samples, is the number of radar acquisition measurement points, is the radar time window, is the radar main frequency, is a fixed ratio;

[0011] S3: Calculate the sum of the data points within the window ,

[0012] ;

[0013] Among them, is the rd data point in ;

[0014] S4: Traverse all data points within , calculate the value of each data point after zero-offset correction, and update the sliding window,

[0015] ;

[0016] Among them, is the cumulative sum at the rd point, ;

[0017] S5: Subtract the sliding average value from the original data for zero-offset correction,

[0018] ;

[0019] Among them, is the value after zero-offset correction, is the l-th data point in the i-th row of matrix B;

[0020] Update the calculated value to , the l-th data point of

[0021] ;

[0022] S6: Repeat steps S2 - S5 to cyclically update the values within the entire matrix B.

[0023] Preferably, in step S2, Round down to an integer.

[0024] The present invention has the following advantages: The present invention adjusts the size of the sliding window based on parameters such as the sampling rate, frequency, and time window of the radar signal, thereby controlling the range of the smoothing operation and dynamically calculating the zero - bias correction, ensuring that the signal can be effectively smoothed, noise removed, while maintaining the effective information of the signal during zero - bias correction. It is applicable to processing radar signals or other time - series data with noise and fluctuations. Especially in the case where the signal changes greatly or there is a lot of noise, it can provide a more accurate and stable correction effect. Detailed implementation mode

[0025] It should be noted that, without conflict, the implementation modes and features in the present invention can be combined with each other.

[0026] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "set", "installed", "connected", "linked" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0027] In this embodiment, a zero - bias correction method for a ground - penetrating radar includes the following steps:

[0028] S1: Collect radar data Matrix B, the size of matrix B is ;

[0029] S2: Traverse matrix B column - by - column, take a column of data , is matrix, is the th column of data, calculate the size of the sliding window ,

[0030] ;

[0031] Wherein, is the number of radar samples, is the number of measurement points collected by the radar, is the radar time window, is the radar main frequency, is a fixed ratio; preferably, rounds down to an integer.

[0032] S3: Calculate the sum of data points within the window ,

[0033] ;

[0034] wherein, is the th data point;

[0035] S4: Traverse all data points within, calculate the value of each data point after zero-offset correction , and update the sliding window,

[0036] ;

[0037] wherein, is the cumulative sum at the th point, ;

[0038] S5: Subtract the sliding average value from the original data for zero-offset correction,

[0039] ;

[0040] wherein, is the value after zero-offset correction, is the l-th data point in the i-th row of matrix B;

[0041] Update the calculated value to in, the l-th data point of

[0042] ;

[0043] S6: Repeat steps S2 - S5 to cyclically update the values within the entire matrix B. Adjust the sliding window size based on parameters such as the sampling rate, frequency, and time window of the radar signal, thereby controlling the scope of the smoothing operation, and dynamically calculate the zero - bias correction to ensure that the signal can be effectively smoothed, noise removed, while maintaining the effective information of the signal when performing zero - bias correction. It is applicable to processing radar signals or other time - series data with noise and fluctuations. Especially in the case where the signal changes greatly or there is a lot of noise, it can provide a more accurate and stable correction effect; that is to say, the main function of the present invention is to perform zero - bias adjustment on the radar data of each measurement point, reduce noise, smooth the data, and improve the data quality and data accuracy.

[0044] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A ground penetrating radar zero bias correction method, characterized in that: The following steps are involved: S1: Collect radar data Matrix B, the size of matrix B is ; S2: Traverse matrix B by column and take a column of data , for The matrix of For the Column data, calculate sliding window The size of ； in, is the number of radar samples, is the number of radar acquisition points, is the radar time window, is the main frequency of the radar, is a fixed ratio; S3: Compute within the window The sum of the data points , ； in, for Middle data points; S4: Traversal For all data points within, calculate the value of each data point after zero bias correction , and update the sliding window, ； in, For the The cumulative sum of the points, ; S5: Subtract the sliding average value from the original data to perform zero bias correction. ； in, for The value after zero bias correction, is the lth data point in the i-th row of matrix B; Update the calculated value to middle, The lth data point of is: ； S6: Repeat steps S2 to S5 to cyclically update the values ​​in the entire matrix B.

2. The method for zero bias correction of ground penetrating radar according to claim 1, characterized in that: In the step S2, Round down to an integer.

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