A method, device and storage medium for calculating maximum detection depth of ground penetrating radar

Abstract

The application discloses a kind of methods for calculating maximum depth of ground penetrating radar, comprising the following steps: step 1, determine the path loss of ground penetrating radar certain frequency electromagnetic wave signal from transmitting end to receiving end: step 2, determine the transmission dynamic range of ground penetrating radar under certain frequency electromagnetic wave signal;Step 3, determine the electromagnetic wave attenuation per meter of the underground medium of detection area;Step 4, determine the maximum depth of ground penetrating radar certain frequency electromagnetic wave signal in the underground medium of detection area.The method disclosed in the application can accurately obtain the attenuation of different frequency electromagnetic wave signals of ground penetrating radar in the underground medium of a specific detection area, and then accurately obtain the maximum depth of ground penetrating radar in the underground medium and the information of underground target position, reduce the measurement error, improve the detection accuracy, and ensure the reliability of the detection obtained underground target depth information.

Description

Technical Field

[0001] This invention belongs to the field of ground penetrating radar research, and specifically relates to a method, device and storage medium for calculating the maximum penetration depth of ground penetrating radar in this field. Background Technology

[0002] Ground penetrating radar has extremely broad application prospects. When using ground penetrating radar to detect underground targets, due to the complex and variable underground environment, the electromagnetic wave attenuation of the same medium (such as clay or rock strata) in different areas will also vary depending on factors such as the water content, density, and impurity composition of the medium. If commonly used engineering parameters are used for calculation, only the maximum penetration depth of the ground penetrating radar and the depth and size information of the underground target can be roughly obtained. This cannot be accurately applied to the specific detection site and affects the entire detection process. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method, device and storage medium for calculating the maximum penetration depth of ground penetrating radar, which can accurately obtain the attenuation of electromagnetic wave signals of different frequencies of ground penetrating radar in the underground medium of a specific detection area.

[0004] The present invention adopts the following technical solution:

[0005] An improved method for calculating the maximum penetration depth of ground-penetrating radar includes the following steps:

[0006] Step 1: Determine the path loss L of a certain frequency electromagnetic wave signal from the transmitter to the receiver of the ground penetrating radar. T :

[0007]

[0008] In the above formula, L e For the efficiency of the transmit and receive antennas, For antenna matching loss, L t1 L represents the loss of electromagnetic wave signals from the air incident on the underground medium of the detection area. t2 L represents the loss of electromagnetic wave signals returning to air from the underground medium in the detection area. s For the propagation loss of electromagnetic waves along spatial paths, L sc Scattering loss for different dielectric layers;

[0009] Step 2: Determine the dynamic range S of the ground-penetrating radar for transmitting and receiving electromagnetic wave signals at a certain frequency. T :

[0010]

[0011] In the above formula, This represents the maximum voltage output by a ground-penetrating radar under a specific frequency of electromagnetic wave signal. This is the minimum voltage that a ground-penetrating radar can detect under a certain frequency of electromagnetic wave signal;

[0012] Calculate the minimum sensitivity of the ground-penetrating radar antenna receiver. :

[0013]

[0014] In the above formula, Boltzmann's constant, At room temperature For bandwidth, The noise figure of the ground-penetrating radar;

[0015] Calculate the corresponding minimum voltage :

[0016]

[0017] In the above formula, The system impedance;

[0018] Step 3: Determine the electromagnetic wave attenuation L per meter of the underground medium in the detection area. a :

[0019] The ground-penetrating radar's antenna transmitter and receiver are placed side-by-side against the surface of the underground medium in the detection area, and directly above the underground target, which is buried at a depth of 0.5m.

[0020] Turn on the ground-penetrating radar and transmit pulse signals underground. Simultaneously, receive radar echo signals and record the positive peak value AA of the reflected wave from the underground target. Assuming the ground-penetrating radar's AD chip is N-bit and the input voltage range is -YV to +YV, then the actual voltage value A of the reflected wave from the underground target is:

[0021]

[0022] Raise the ground-penetrating radar's antenna transmitter and receiver horizontally side by side, and place the ground target directly below the ground-penetrating radar's antenna transmitter and receiver, 0.5m away from the ground-penetrating radar's antenna detection surface;

[0023] Next, turn on the ground-penetrating radar, transmit pulse signals to the ground target, and simultaneously receive radar echo signals. Record the positive peak value BB of the reflected wave from the ground target. Then, the actual voltage value B of the reflected wave from the ground target is:

[0024]

[0025] By default, electromagnetic waves in the 100MHz to 1GHz range attenuate by 0dB / m in air, then L a for:

[0026] ;

[0027] Step 4: Determine the maximum penetration depth L of a certain frequency electromagnetic wave signal of the ground penetrating radar in the underground medium of the detection area:

[0028] .

[0029] Furthermore, in step 1, L t1 and L t2 The calculation formula is:

[0030]

[0031] In the above formula, Z a Z is the characteristic impedance of air. m To detect the characteristic impedance of the underground medium in the area.

[0032] Furthermore, in step 1, L s The calculation formula is:

[0033]

[0034] In the above formula, G t For the transmit antenna gain, A r δ is the area of ​​the receiving antenna, R is the cross-sectional area of ​​the underground target, and R is the detection depth.

[0035] Furthermore, in step 1, L sc The calculation formula is:

[0036]

[0037] In the above formula, Z2 is the impedance of the underground target.

[0038] Furthermore, in step 3, both the underground target and the above-ground target are square metal plates measuring 1m × 1m.

[0039] An improved device for calculating the maximum depth of a ground-penetrating radar includes: a processor; a memory storing executable instructions of the processor; the processor being configured to perform the steps of the method described above by executing the executable instructions.

[0040] A computer-readable storage medium for storing a program, wherein the improvement is that the program, when executed, implements the steps of the above method.

[0041] The beneficial effects of this invention are:

[0042] The method disclosed in this invention can accurately obtain the attenuation of electromagnetic wave signals of different frequencies of ground penetrating radar in the underground medium of a specific detection area, thereby accurately obtaining information such as the maximum penetration depth of the ground penetrating radar in the underground medium and the location of underground targets, reducing measurement errors, improving detection accuracy, and ensuring the reliability of the underground target depth information obtained by detection.

[0043] The method disclosed in this invention enables ground penetrating radar to be applied to various types of underground media, including but not limited to rocks, soil, and water, without requiring excessive pre-setting of the media type. This expands the applicability of ground penetrating radar, improves the versatility and flexibility of measurements, reduces the complexity and time cost of on-site operations, and improves testing efficiency.

[0044] The method disclosed in this invention can complete the detection using ground penetrating radar itself, without the need for additional measuring equipment, thus reducing implementation costs and enhancing the market competitiveness of ground penetrating radar. Attached Figure Description

[0045] Figure 1 This is a flowchart illustrating the method of the present invention;

[0046] Figure 2 This is a schematic diagram of ground-penetrating radar testing the electromagnetic wave attenuation per meter of underground medium.

[0047] Figure 3 This is a schematic diagram of a ground-penetrating radar testing the attenuation of electromagnetic waves per meter in the air.

[0048] Figure 4 These are radar echo signal diagrams for both underground media and air. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0050] Example 1: This example discloses a method for calculating the maximum penetration depth of a ground-penetrating radar, such as... Figure 1 As shown, it includes the following steps:

[0051] Step 1: Determine the path loss L of a certain frequency electromagnetic wave signal from the transmitter to the receiver of the ground penetrating radar. T :

[0052]

[0053] In the above formula, L e For the efficiency of the transmit and receive antennas, For antenna matching loss, Lt1 L represents the loss of electromagnetic wave signals from the air incident on the underground medium of the detection area. t2 L represents the loss of electromagnetic wave signals returning to air from the underground medium in the detection area. s For the propagation loss of electromagnetic waves along spatial paths, L sc Scattering loss for different dielectric layers;

[0054] Antennas of different frequencies have different attenuation in the same underground medium. This embodiment uses the ground-penetrating radar of the 22nd Research Institute of China Electronics Technology Group Corporation (CETC) paired with a low-frequency GC150MHz dipole antenna as an example for illustration.

[0055] The efficiency of a GC150MHz dipole antenna is typically 2dB, therefore the transmit / receive antenna efficiency L... e 4dB; Antenna matching loss 1dB , For the propagation loss between air and underground media:

[0056]

[0057] In the above formula, Z a =377Ω is the characteristic impedance of air, Z m =125Ω is the characteristic impedance of the underground medium in the detection area.

[0058]

[0059] In the above formula, G t The gain of the transmitting antenna varies depending on the ground-penetrating radar. The ground-penetrating radar used in this embodiment has a gain of 0.6 A. r For the receiving antenna area, the GC150MHz dipole antenna used in this embodiment is 42cm * 20cm = 0.084m. 2 δ represents the cross-sectional area of ​​the underground target. In this embodiment, the underground target detected is a 1m*1m metal plate, so δ=1m. 2 The detection depth R = 1m, which is the distance that the electromagnetic wave signal of the ground penetrating radar travels in the underground medium.

[0060] Scattering loss L of different dielectric layers sc The characteristic impedance of different dielectric layers is determined, and its calculation formula is as follows:

[0061]

[0062] In the above formula, Z m =125Ω, Z2=89Ω is the impedance of the underground target.

[0063] In summary, at an operating frequency of 150MHz, the path loss L Tfor:

[0064]

[0065] Step 2: Determine the dynamic range S of the ground-penetrating radar for transmitting and receiving electromagnetic wave signals at a certain frequency. T :

[0066]

[0067] In the above formula, This represents the maximum voltage output by a ground-penetrating radar under a specific frequency of electromagnetic wave signal. This is the minimum voltage that a ground-penetrating radar can detect under a certain frequency of electromagnetic wave signal;

[0068] Calculate the minimum sensitivity of the ground-penetrating radar antenna receiver. :

[0069]

[0070] In the above formula, Boltzmann constant (1.38 * 10) -23 J / K), room temperature =290K, approximately 17 o C, For the receiver of the 150MHz frequency antenna of the ground-penetrating radar in this embodiment, the bandwidth is 150MHz. 1dB is the noise figure of ground-penetrating radar;

[0071] The minimum sensitivity was calculated as follows: ,

[0072] Calculate the corresponding minimum voltage :

[0073]

[0074] In the above formula, This is the system impedance, default 50Ω;

[0075] The corresponding minimum voltage is calculated. :

[0076] = = = ≈6.3*10 -6 V.

[0077] Obtain the minimum detectable voltage value It is 6.3*10 -6 V. The maximum output voltage of the 150MHz ground penetrating radar transmitter is designed to be 220V. Therefore, the transmit / receive dynamic range S of the ground penetrating radar system is...T =20lg(220 / 6.3*0.000001) ≈150dB.

[0078] Step 3: Quickly and accurately determine the electromagnetic wave attenuation L per meter of the underground medium in the detection area. a :

[0079] Different underground media exhibit different attenuation values ​​at different operating frequencies. The table below shows the commonly used attenuation parameters for different underground media at different frequencies in engineering applications:

[0080]

[0081] like Figure 2 As shown, the antenna transmitter and antenna receiver of the ground penetrating radar are placed side by side against the surface of the underground medium in the detection area and directly above the underground target, which is buried at a depth of 0.5m and is a square metal plate with a size of 1m×1m.

[0082] Turn on the ground penetrating radar main control unit, which controls the pulse generation and step control modules to transmit pulse signals underground. At the same time, the radar main control unit controls the radar receiver to receive radar echo signals, saves a segment of data, and then turns off the ground penetrating radar.

[0083] Open the saved radar data in the radar data processing software and record the positive peak value AA of the reflected wave from the underground target. Here, the reflected wave is the radar signal after the radar signal is reflected by the metal plate in the underground medium and the path is attenuated by a total of 0.5*2=1m.

[0084] Assuming the ground-penetrating radar's AD chip is 32-bit and its input voltage range is -5V to +5V, then the actual voltage value A of the reflected wave from the underground target is:

[0085]

[0086] like Figure 3 As shown, the antenna transmitter and antenna receiver of the ground penetrating radar are raised horizontally side by side, and the ground target is placed directly below the antenna transmitter and antenna receiver of the ground penetrating radar, 0.5m away from the detection surface of the ground penetrating radar antenna;

[0087] Then, turn on the ground penetrating radar main control unit, control the pulse generation and step control modules to transmit pulse signals to the ground target, and at the same time, control the radar receiver to receive the radar echo signal, save a piece of data and then turn off the ground penetrating radar.

[0088] Open the saved radar data in the radar data processing software and record the positive peak value BB of the ground target's reflected wave. Here, the reflected wave is the radar signal after the radar signal is reflected by the metal plate in the air and then attenuated for a total of 0.5*2=1m.

[0089] The actual voltage value B of the reflected wave from the ground target is:

[0090]

[0091] The peak values ​​of the reflected waves from the two targets differ due to variations in the amount of attenuation in the medium. Figure 4 As shown, the blue curve represents the radar echo response of ground penetrating radar in underground media, and the red curve represents the radar echo response of ground penetrating radar in air.

[0092] By default, electromagnetic waves in the 100MHz to 1GHz range attenuate by 0dB / m in air, then L a for:

[0093] ;

[0094] Step 4: Determine the maximum penetration depth L of a certain frequency electromagnetic wave signal of the ground penetrating radar in the underground medium of the detection area:

[0095] .

[0096] If the electromagnetic wave attenuation per meter of the underground medium in a certain detection area is measured as L a If the value is 10 dB / m, then the maximum penetration depth of the ground penetrating radar in this area can be obtained as L = (150 - 46.56) / 10 = 10.344 m.

[0097] This embodiment also discloses a calculation device for the maximum penetration depth of a ground-penetrating radar, comprising: a processor; a memory storing executable instructions of the processor; the processor being configured to perform the steps of the above-described method by executing the executable instructions. A computer-readable storage medium is also disclosed for storing a program, wherein the improvement is that the program, when executed, implements the steps of the above-described method.

Claims

1. A method for calculating the maximum penetration depth of ground-penetrating radar, characterized in that, Includes the following steps: Step 1: Determine the path loss L of a certain frequency electromagnetic wave signal from the transmitter to the receiver of the ground penetrating radar. T : In the above formula, L e For the efficiency of the transmit and receive antennas, For antenna matching loss, L t1 L represents the loss of electromagnetic wave signals from the air incident on the underground medium of the detection area. t2 L represents the loss of electromagnetic wave signals returning to air from the underground medium in the detection area. s For the propagation loss of electromagnetic waves along spatial paths, L sc Scattering loss for different dielectric layers; Step 2: Determine the dynamic range S of the ground-penetrating radar for transmitting and receiving electromagnetic wave signals at a certain frequency. T : In the above formula, This represents the maximum voltage output by a ground-penetrating radar under a specific frequency of electromagnetic wave signal. This is the minimum voltage that a ground-penetrating radar can detect under a certain frequency of electromagnetic wave signal; Calculate the minimum sensitivity of the ground-penetrating radar antenna receiver. : In the above formula, Boltzmann's constant, At room temperature For bandwidth, The noise figure of the ground-penetrating radar; Calculate the corresponding minimum voltage : In the above formula, The system impedance; Step 3: Determine the electromagnetic wave attenuation L per meter of the underground medium in the detection area. a : The ground-penetrating radar's antenna transmitter and receiver are placed side-by-side against the surface of the underground medium in the detection area, and directly above the underground target, which is buried at a depth of 0.5m. Turn on the ground-penetrating radar and transmit pulse signals underground. Simultaneously, receive radar echo signals and record the positive peak value AA of the reflected wave from the underground target. Assuming the ground-penetrating radar's AD chip is N-bit and the input voltage range is -YV to +YV, then the actual voltage value A of the reflected wave from the underground target is: Raise the ground-penetrating radar's antenna transmitter and receiver horizontally side by side, and place the ground target directly below the ground-penetrating radar's antenna transmitter and receiver, 0.5m away from the ground-penetrating radar's antenna detection surface; Next, turn on the ground-penetrating radar, transmit pulse signals to the ground target, and simultaneously receive radar echo signals. Record the positive peak value BB of the reflected wave from the ground target. Then, the actual voltage value B of the reflected wave from the ground target is: By default, electromagnetic waves in the 100MHz to 1GHz range attenuate by 0dB / m in air, then L a for: ； Step 4: Determine the maximum penetration depth L of a certain frequency electromagnetic wave signal of the ground penetrating radar in the underground medium of the detection area: 。 2. The method for calculating the maximum penetration depth of ground-penetrating radar according to claim 1, characterized in that: In step 1, L t1 and L t2 The calculation formula is: In the above formula, Z a Z is the characteristic impedance of air. m To detect the characteristic impedance of the underground medium in the area.

3. The method for calculating the maximum penetration depth of ground-penetrating radar according to claim 1, characterized in that: In step 1, L s The calculation formula is: In the above formula, G t For the transmit antenna gain, A r δ is the area of ​​the receiving antenna, R is the cross-sectional area of ​​the underground target, and R is the detection depth.

4. The method for calculating the maximum penetration depth of ground-penetrating radar according to claim 1, characterized in that: In step 1, L sc The calculation formula is: In the above formula, Z2 is the impedance of the underground target.

5. The method for calculating the maximum penetration depth of ground-penetrating radar according to claim 1, characterized in that: In step 3, both the underground target and the above-ground target are square metal plates measuring 1m × 1m.

6. A calculation device for the maximum penetration depth of a ground-penetrating radar, characterized in that, include: processor; A memory storing executable instructions of the processor; the processor is configured to perform the steps of the method of claim 1 by executing the executable instructions.

7. A computer-readable storage medium for storing a program, characterized in that: When the program is executed, it performs the steps of the method of claim 1.

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