Automatic calibration device for ground penetrating radar

Abstract

The invention discloses a ground penetrating radar automatic calibration device which comprises a main frame of a cubic structure, a left side mask and a right side mask which are arranged on the two sides of the main frame respectively, a carrying table arranged in the main frame and used for carrying a radar antenna and a reflecting plate arranged at the top of the main frame, and the bottom measuring face of the radar antenna faces the reflecting plate. Lead screw lifting mechanisms used for lifting the carrying table are symmetrically arranged in the left side mask and the right side mask, four horizontal adjusting sliding rails are arranged on the carrying table in a cross structure, and each horizontal adjusting sliding rail is provided with a horizontal adjusting mechanism used for adjusting the level of the bottom measuring face of the radar antenna. A clamp mechanism guide rail is arranged in the area, located between every two adjacent horizontal adjusting sliding rails, of the carrying table, radar clamps are arranged on the clamp mechanism guide rails, and an antenna thickness equal-height measuring swing arm is arranged in the mask. According to the invention, clamping calibration of radar antennas of various different shapes can be realized, and the use state of the calibrated radar can be judged and evaluated more accurately.

Description

Technical Field

[0001] The invention belongs to the technical field of ground penetrating radar calibration, and in particular relates to an automatic calibration device for ground penetrating radar. Background Art

[0002] In the transportation industry, pavement thickness is one of the most important indicators for pavement engineering quality control during highway construction and completion inspection. In the past, conventional methods for testing the pavement thickness of high-grade highways mainly included sand filling method, ring knife method and drilling coring method. The most widely used drilling coring method is not only inefficient and poorly representative, but also causes damage to the highway. With the improvement of ground penetrating radar detection accuracy, it has been widely used in the field of engineering quality inspection in recent years, such as in railway and highway tunnel linings, highway pavements, airport runways and other engineering structures, to detect pavement surface thickness, lining thickness, voids and cavities, seepage zones, insufficient backfill, surrounding rock disturbance and other problems.

[0003] Ground penetrating radar is an efficient shallow geophysical detection technology. It emits high-frequency electromagnetic pulse waves, utilizes the differences in electrical parameters of underground media, and analyzes and infers the structure and physical properties of the media based on the kinematic and dynamic characteristics of the echo, such as amplitude, waveform and frequency. It has the characteristics of non-destructive, high efficiency, high resolution, and strong anti-interference ability. Therefore, it is widely used in the measurement of pavement structure layer thickness and defect identification (segregation, collapse, voiding, cracks, etc.). Therefore, there is a need for quantitative requirements on the measurement accuracy of ground penetrating radar. The scientificity and rationality of the current calibration device for ground penetrating radar need to be considered, and the accuracy of its calibration results will affect the accuracy of the measurement results of ground penetrating radar. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an automatic calibration device for ground penetrating radar in view of the deficiencies in the above-mentioned prior art. The device has a novel and reasonable design and can realize the clamping calibration of radar antennas of various shapes, and can give a more accurate judgment and evaluation of the usage status of the calibrated radar, so as to facilitate its popularization and use.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a ground penetrating radar automatic calibration device, characterized in that: it includes a main frame of a cubic structure, a left mask and a right mask respectively arranged on both sides of the main frame, a carrier arranged in the main frame for carrying the radar antenna, and a reflector arranged on the top of the main frame, the bottom measuring surface of the radar antenna faces the reflector, and the left mask and the right mask are symmetrically provided with screw lifting mechanisms for lifting the carrier, and the slider of the screw lifting mechanism is fixedly connected with a carrier clamping slider for clamping the carrier, four horizontal adjustment rails are arranged on the carrier in a cross structure, each horizontal adjustment rail is provided with a horizontal adjustment mechanism for adjusting the level of the bottom measuring surface of the radar antenna, a clamp mechanism guide rail is arranged in the area between two adjacent horizontal adjustment rails on the platform, a radar clamp is arranged on the clamp mechanism guide rail, and an antenna thickness contour measurement swing arm is arranged in the left mask or the right mask.

[0006] The above-mentioned automatic calibration device for ground penetrating radar is characterized in that a plurality of footings are arranged at the bottom of the main frame.

[0007] The above-mentioned ground penetrating radar automatic calibration device is characterized in that: an LVDT linear displacement sensor is provided on the top inner measuring surface of the reflector, a reflector connecting frame is provided on the top outer side of the reflector, a reflector adjustment seat is provided on the top of the main frame, and a reflector adjustment rod is provided on the reflector connecting frame, which cooperates with the reflector adjustment seat and is used to adjust the level of the reflector. The number of reflector adjustment seats and reflector adjustment rods are both multiple and connected one-to-one.

[0008] The above-mentioned automatic calibration device for ground penetrating radar is characterized in that: the horizontal adjustment mechanism includes an adjusting slide that slides along the sliding groove in the horizontal adjustment slide rail, a slide top plate is arranged on the top of the adjusting slide, a support frame that supports the radar antenna is arranged on the upper side of the slide top plate, an adjustment knob is arranged on the lower side of the slide top plate, and the top end of the adjusting screw of the adjustment knob passes through the slide top plate and is fixedly connected to the bottom of the support frame.

[0009] The above-mentioned ground penetrating radar automatic calibration device is characterized in that: an arc-shaped slide groove is opened in the area between two adjacent horizontal adjustment slide rails on the carrier, one end of the clamping mechanism guide rail is hinged to the central area of ​​the carrier, and the bottom of the other end of the clamping mechanism guide rail cooperates with the corresponding arc-shaped slide groove through a guide block.

[0010] The above-mentioned ground penetrating radar automatic calibration device is characterized in that: the radar fixture includes a fixture mounting seat that cooperates with the fixture mechanism guide rail, a fixture and a push knob for adjusting the horizontal extension length of the fixture are installed on the top of the fixture mounting seat, and a mounting seat fastening mechanism for fixing the radar fixture position is arranged at the bottom of the fixture mounting seat.

[0011] The above-mentioned ground penetrating radar automatic calibration device is characterized in that: the antenna thickness contour measurement swing arm includes a lifting column arranged beside the carrier, a lifting seat is slidably arranged on the lifting column, a contour platform is connected to the top of the lifting seat, a contour ruler is horizontally hinged on the top of the contour platform, and a lifting handle for adjusting the height of the lifting seat is arranged on the top of the lifting column.

[0012] The above-mentioned automatic calibration device for ground penetrating radar is characterized in that a temperature and humidity sensor is installed on the wall surface of the left mask or the right mask facing the inner side of the main frame.

[0013] The above-mentioned ground penetrating radar automatic calibration device is characterized in that: a power supply, a power leakage protection module, a PLC control module, a servo drive control module, a signal processing and communication module are arranged inside the left mask or the right mask; a display screen controlled by the PLC control module is arranged outside the left mask or the right mask.

[0014] The above-mentioned automatic calibration device for ground penetrating radar is characterized in that: when the PLC control module performs automatic calibration of the ground penetrating radar, the following steps are included:

[0015] Step 1: Collect ambient temperature and humidity: Ground penetrating radar automatic calibration requires ambient temperature to be between 10° and 40°, and ambient humidity to be less than 50%;

[0016] Step 2: Adjust the distance between the radar antenna measurement surface and the reflector so that the distance between the radar antenna measurement surface and the reflector is greater than 600 mm and not less than the wavelength of the electromagnetic wave of the frequency of the antenna being tested in the air;

[0017] Step 3: Leveling the ground penetrating radar automatic calibration device: The leveling of the ground penetrating radar automatic calibration device includes leveling of multiple feet, leveling of the platform, leveling of the support frame and leveling of the reflector;

[0018] Step 4: Fix the radar antenna: Use the radar fixture and the fixture mechanism guide rail to fix the radar antenna;

[0019] Step 5, judging whether the horizontality of the radar antenna measurement surface meets the radar antenna measurement requirements: using a level ruler to measure whether the horizontality of the radar antenna measurement surface meets the radar antenna measurement requirements. When the horizontality of the radar antenna measurement surface does not meet the radar antenna measurement requirements, loop step 3; when the horizontality of the radar antenna measurement surface meets the radar antenna measurement requirements, execute step 6;

[0020] Step 6: According to the formula Calculate the radar wave speed v of a wave in air i , where L is the distance between the radar antenna measurement surface and the reflector adjusted in step 2, t i It is the two-way travel time of radar wave;

[0021] Calculate the arithmetic mean of the radar wave speeds of the five waves as the radar wave speed

[0022] According to the formula Calculation of relative error δ of radar wave velocity measurement in air v , where c0 is the standard value of electromagnetic wave velocity in air;

[0023] When the relative error of radar wave velocity measurement in air is δ v When the relative error threshold is within the range, the ground penetrating radar does not need to be calibrated; when the relative error of the radar wave velocity measurement in the air is δ v When the relative error threshold is exceeded, the radar wave velocity v is compensated to achieve automatic calibration of the ground penetrating radar.

[0024] The beneficial effects of the present invention are as follows: the design is novel and reasonable, the screw lifting mechanism can drive the radar antenna to rise and fall to meet the needs of different measuring distances, four horizontal adjustment slide rails are arranged in a cross structure on the carrier, each horizontal adjustment slide rail is provided with a horizontal adjustment mechanism for adjusting the level of the bottom measuring surface of the radar antenna, so as to achieve the leveling of the measuring plane, and a radar clamp is arranged on the guide rail of the clamp mechanism, so as to achieve the clamping calibration of radar antennas of various shapes, and the calibration result improves the original accuracy, and can make a more accurate judgment and evaluation on the use status of the calibrated radar, so as to provide a reliable technical basis for the technical evaluation of the ground penetrating radar, find out the instruments that need to be calibrated or abandoned, thereby ensuring the reliability of the ground penetrating radar measurement data and facilitating the popularization and use.

[0025] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 It is a front view of the present invention.

[0028] Description of reference numerals:

[0029] 1—main frame; 2—left side mask; 3—right side mask;

[0030] 4—ground foot; 5—reflector; 6—reflector connecting frame;

[0031] 7—reflector plate adjustment seat; 8—reflector plate adjustment rod; 9—screw rod lifting mechanism;

[0032] 10—carrier clamping slider; 11—carrier; 12—horizontal adjustment slide rail;

[0033] 13—Horizontal adjustment mechanism; 14—Clamp mechanism guide rail; 15—Clamp mounting seat;

[0034] 16—clamp; 18—advance knob; 19—mounting seat fastening mechanism;

[0035] 20—arc-shaped slide; 21—lifting column; 22—lifting seat;

[0036] 23—Lifting handle; 24—Equal height platform; 25—Equal height ruler;

[0037] 26—display screen; 27—adjusting slide seat; 28—slide seat top plate;

[0038] 29—support rack; 30—adjustment knob. DETAILED DESCRIPTION

[0039] like Figure 1 and Figure 2 As shown, the present invention includes a main frame 1 of a cubic structure, a left mask 2 and a right mask 3 respectively arranged on both sides of the main frame 1, a carrier 11 arranged in the main frame 1 for carrying a radar antenna, and a reflector 5 arranged on the top of the main frame 1, the bottom measuring surface of the radar antenna faces the reflector 5, and screw lifting mechanisms 9 for lifting and lowering the carrier 11 are symmetrically arranged in the left mask 2 and the right mask 3, and a carrier clamping slider 10 for clamping the carrier 11 is fixedly connected to the slider of the screw lifting mechanism 9, and four horizontal adjustment rails 12 are arranged in a cross structure on the carrier 11, and each horizontal adjustment rail 12 is provided with a horizontal adjustment mechanism 13 for adjusting the horizontal level of the bottom measuring surface of the radar antenna, and a clamp mechanism guide rail 14 is arranged in the area between two adjacent horizontal adjustment rails 12 on the carrier 11, and a radar clamp is arranged on the clamp mechanism guide rail 14, and an antenna thickness isometric measurement swing arm is arranged in the left mask 2 or the right mask 3.

[0040] It should be noted that the screw lifting mechanism can drive the radar antenna to rise and fall to meet the needs of different measuring distances. Four horizontal adjustment slide rails are arranged in a cross structure on the carrier. Each horizontal adjustment slide rail is provided with a horizontal adjustment mechanism for adjusting the level of the bottom measuring surface of the radar antenna to achieve the leveling of the measuring plane. A radar clamp is arranged on the guide rail of the clamp mechanism, which can realize the clamping and calibration of radar antennas of various shapes. The calibration result improves the original accuracy, and a more accurate judgment and evaluation can be made on the use status of the calibrated radar, which provides a reliable technical basis for the technical evaluation of ground penetrating radar, finds out the instruments that need to be adjusted or abandoned, and thus ensures the reliability of ground penetrating radar measurement data.

[0041] In actual use, it can ensure that the calibration accuracy of the ground penetrating radar reaches a high level, can provide reliable and accurate measurement data, reduce the impact of human factors on the calibration results, and has good stability and reliability. Under long-term operation and complex environments, the system can maintain stable performance and ensure the accuracy and consistency of the calibration results. It supports customized settings and development according to actual needs in the later stage, meets the changes in different application scenarios and user needs, and improves the flexibility and adaptability of the system.

[0042] The carrier is the basic platform for carrying the antenna. It is used to lift and fasten the radar antenna. After the overall frame structure is installed and debugged, in order to improve the detection and calibration accuracy, the level of the entire carrier plate can be adjusted by the horizontal adjustment screws. The fastening screws are used to adjust the level and then fix it.

[0043] In this embodiment, a plurality of feet 4 are provided at the bottom of the main frame 1 .

[0044] In this embodiment, an LVDT linear displacement sensor is provided on the top inner measuring surface of the reflector 5, a reflector connecting frame 6 is provided on the top outer side surface of the reflector 5, a reflector adjustment seat 7 is provided on the top of the main frame 1, and a reflector adjustment rod 8 is provided on the reflector connecting frame 6, which cooperates with the reflector adjustment seat 7 and is used to adjust the level of the reflector 5. The number of the reflector adjustment seat 7 and the reflector adjustment rod 8 are both multiple and connected one by one.

[0045] In this embodiment, the horizontal adjustment mechanism 13 includes an adjusting slide 27 that slides along the inner groove of the horizontal adjustment slide rail 12, a slide top plate 28 is arranged on the top of the adjusting slide 27, a support rack 29 that supports the radar antenna is arranged on the upper side of the slide top plate 28, an adjusting knob 30 is arranged on the lower side of the slide top plate 28, and the top end of the adjusting screw of the adjusting knob 30 passes through the slide top plate 28 and is fixedly connected to the bottom of the support rack 29.

[0046] In this embodiment, an arc-shaped slide groove 20 is opened in the area between two adjacent horizontal adjustment rails 12 on the platform 11, one end of the clamping mechanism guide rail 14 is hinged to the central area of ​​the platform 11, and the bottom of the other end of the clamping mechanism guide rail 14 cooperates with the corresponding arc-shaped slide groove 20 through a guide block.

[0047] In this embodiment, the radar clamp includes a clamp mounting seat 15 that cooperates with the clamp mechanism guide rail 14, a clamp 16 and a push knob 18 for adjusting the horizontal extension length of the clamp 16 are installed on the top of the clamp mounting seat 15, and a mounting seat fastening mechanism 19 for fixing the position of the radar clamp is arranged at the bottom of the clamp mounting seat 15.

[0048] In this embodiment, the antenna thickness contour measurement swing arm includes a lifting column 21 arranged next to the carrier 11, a lifting seat 22 is slidably arranged on the lifting column 21, a contour platform 24 is connected to the top of the lifting seat 22, a contour ruler 25 is horizontally hinged on the top of the contour platform 24, and a lifting handle 23 for adjusting the height of the lifting seat 22 is arranged on the top of the lifting column 21.

[0049] In this embodiment, a temperature and humidity sensor is installed on the wall surface of the left cover plate 2 or the right cover plate 3 facing the inner side of the main frame 1.

[0050] In this embodiment, a power supply, a power leakage protection module, a PLC control module, a servo drive control module, and a signal processing and communication module are disposed inside the left mask 2 or the right mask 3; a display screen 26 controlled by the PLC control module is disposed outside the left mask 2 or the right mask 3.

[0051] In this embodiment, when the PLC control module performs automatic calibration of the ground penetrating radar, the following steps are included:

[0052] Step 1: Collect ambient temperature and humidity: Ground penetrating radar automatic calibration requires ambient temperature to be between 10° and 40°, and ambient humidity to be less than 50%;

[0053] Step 2: Adjust the distance between the radar antenna measurement surface and the reflector so that the distance between the radar antenna measurement surface and the reflector is greater than 600 mm and not less than the wavelength of the electromagnetic wave of the frequency of the antenna being tested in the air;

[0054] Step 3: Leveling of the ground penetrating radar automatic calibration device: The leveling of the ground penetrating radar automatic calibration device includes leveling of multiple feet 4, leveling of the platform 11, leveling of the support frame 29 and leveling of the reflector 5;

[0055] Step 4, fixing the radar antenna: using the radar fixture and the fixture mechanism guide rail 14 to fix the radar antenna;

[0056] Step 5, judging whether the horizontality of the radar antenna measurement surface meets the radar antenna measurement requirements: using a level ruler to measure whether the horizontality of the radar antenna measurement surface meets the radar antenna measurement requirements. When the horizontality of the radar antenna measurement surface does not meet the radar antenna measurement requirements, loop step 3; when the horizontality of the radar antenna measurement surface meets the radar antenna measurement requirements, execute step 6;

[0057] Step 6: According to the formula Calculate the radar wave speed v of a wave in air i , where L is the distance between the radar antenna measurement surface and the reflector adjusted in step 2, and the distance is measured using the antenna thickness and height measurement swing arm, t i It is the two-way travel time of radar wave;

[0058] Calculate the arithmetic mean of the radar wave speeds of the five waves as the radar wave speed

[0059] According to the formula Calculation of relative error δ of radar wave velocity measurement in air v , where c0 is the standard value of electromagnetic wave velocity in air;

[0060] When the relative error of radar wave velocity measurement in air is δ v When the relative error threshold is within the range, the ground penetrating radar does not need to be calibrated; when the relative error of the radar wave velocity measurement in the air is δ v When the relative error threshold is exceeded, the radar wave velocity v is compensated to achieve automatic calibration of the ground penetrating radar.

[0061] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A ground penetrating radar automatic calibration device, characterized in that: The invention comprises a main frame (1) of a cubic structure, a left mask (2) and a right mask (3) respectively arranged on both sides of the main frame (1), a platform (11) arranged in the main frame (1) for carrying a radar antenna, and a reflector (5) arranged on the top of the main frame (1), wherein the bottom measuring surface of the radar antenna faces the reflector (5), and screw lifting mechanisms (9) for lifting the platform (11) are symmetrically arranged in the left mask (2) and the right mask (3), and a slider of the screw lifting mechanism (9) is fixedly connected with a slider for clamping the platform (11). The invention relates to a carrier clamping slide block (10) of a radar antenna. The carrier (11) is provided with four horizontal adjustment slide rails (12) in a cross structure. Each horizontal adjustment slide rail (12) is provided with a horizontal adjustment mechanism (13) for adjusting the horizontal level of the bottom measurement surface of the radar antenna. A clamp mechanism guide rail (14) is provided in the area between two adjacent horizontal adjustment slide rails (12) on the carrier (11). A radar clamp is provided on the clamp mechanism guide rail (14). An antenna thickness equal height measurement swing arm is provided in the left mask (2) or the right mask (3).

2. The automatic calibration device for ground penetrating radar according to claim 1, characterized in that: A plurality of footings (4) are provided at the bottom of the main frame (1).

3. The automatic calibration device for ground penetrating radar according to claim 1, characterized in that: The inner measuring surface of the top of the reflecting plate (5) is provided with an LVDT linear displacement sensor, the outer surface of the top of the reflecting plate (5) is provided with a reflecting plate connecting frame (6), the top of the main frame (1) is provided with a reflecting plate adjusting seat (7), the reflecting plate connecting frame (6) is provided with a reflecting plate adjusting rod (8) which cooperates with the reflecting plate adjusting seat (7) and is used to adjust the level of the reflecting plate (5), and the reflecting plate adjusting seat (7) and the reflecting plate adjusting rod (8) are both provided in multiple numbers and are connected in a one-to-one correspondence.

4. The automatic calibration device for ground penetrating radar according to claim 1, characterized in that: The horizontal adjustment mechanism (13) comprises an adjustment slide (27) which slides along a slide groove in the horizontal adjustment slide rail (12); a slide top plate (28) is arranged on the top of the adjustment slide (27); a support frame (29) which supports the radar antenna is arranged on the upper side of the slide top plate (28); an adjustment knob (30) is arranged on the lower side of the slide top plate (28); and a top end of an adjustment screw of the adjustment knob (30) passes through the slide top plate (28) and is fixedly connected to the bottom of the support frame (29).

5. The automatic calibration device for ground penetrating radar according to claim 1, characterized in that: An arc-shaped slide groove (20) is provided in the area between two adjacent horizontal adjustment slide rails (12) on the carrier (11); one end of the clamp mechanism guide rail (14) is hinged to the central area of ​​the carrier (11); and the bottom of the other end of the clamp mechanism guide rail (14) cooperates with the corresponding arc-shaped slide groove (20) through a guide block.

6. The automatic calibration device for ground penetrating radar according to claim 4, characterized in that: The radar fixture comprises a fixture mounting seat (15) matched with a fixture mechanism guide rail (14); a fixture (16) and a push knob (18) for adjusting the horizontal extension length of the fixture (16) are mounted on the top of the fixture mounting seat (15); and a mounting seat fastening mechanism (19) for fixing the position of the radar fixture is arranged at the bottom of the fixture mounting seat (15).

7. The automatic calibration device for ground penetrating radar according to claim 6, characterized in that: The antenna thickness contour measurement swing arm comprises a lifting column (21) arranged beside a carrier (11); a lifting seat (22) is slidably arranged on the lifting column (21); a contour platform (24) is connected to the top of the lifting seat (22); a contour ruler (25) is horizontally hinged on the top of the contour platform (24); and a lifting handle (23) for adjusting the height of the lifting seat (22) is arranged on the top of the lifting column (21).

8. The automatic calibration device for ground penetrating radar according to claim 1, characterized in that: A temperature and humidity sensor is installed on the wall surface of the left side cover plate (2) or the right side cover plate (3) facing the inner side of the main frame (1).

9. The automatic calibration device for ground penetrating radar according to claim 7, characterized in that: A power supply, a power leakage protection module, a PLC control module, a servo drive control module, and a signal processing and communication module are arranged inside the left mask (2) or the right mask (3); a display screen (26) controlled by the PLC control module is arranged outside the left mask (2) or the right mask (3).

10. The automatic calibration device for ground penetrating radar according to claim 9, characterized in that: When the PLC control module performs automatic calibration of the ground penetrating radar, the following steps are included: Step 1: Collect ambient temperature and humidity: Ground penetrating radar automatic calibration requires ambient temperature to be between 10° and 40°, and ambient humidity to be less than 50%; Step 2: Adjust the distance between the radar antenna measurement surface and the reflector so that the distance between the radar antenna measurement surface and the reflector is greater than 600 mm and not less than the wavelength of the electromagnetic wave of the frequency of the antenna being tested in the air; Step 3: Leveling the ground penetrating radar automatic calibration device: The leveling of the ground penetrating radar automatic calibration device includes leveling of a plurality of feet (4), leveling of the platform (11), leveling of the support frame (29) and leveling of the reflector (5); Step 4: Fix the radar antenna: Use the radar fixture and the fixture mechanism guide rail (14) to fix the radar antenna; Step 5, judging whether the horizontality of the radar antenna measurement surface meets the radar antenna measurement requirements: using a level ruler to measure whether the horizontality of the radar antenna measurement surface meets the radar antenna measurement requirements. When the horizontality of the radar antenna measurement surface does not meet the radar antenna measurement requirements, loop step 3; when the horizontality of the radar antenna measurement surface meets the radar antenna measurement requirements, execute step 6; Step 6: According to the formula Calculate the radar wave speed v of a wave in air i , where L is the distance between the radar antenna measurement surface and the reflector adjusted in step 2, t i It is the two-way travel time of radar wave; Calculate the arithmetic mean of the radar wave speeds of the five waves as the radar wave speed According to the formula Calculation of relative error δ of radar wave velocity measurement in air v , where c0 is the standard value of electromagnetic wave velocity in air; When the relative error of radar wave velocity measurement in air is δ v When the relative error threshold is within the range, the ground penetrating radar does not need to be calibrated; when the relative error of the radar wave velocity measurement in the air is δ v When the relative error threshold is exceeded, the radar wave velocity v is compensated to achieve automatic calibration of the ground penetrating radar.

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