Method for nondestructive detection of buried peat in farmland by radar

Abstract

The invention relates to the technical field of geophysical exploration, in particular to a radar nondestructive detection method for buried peat in a farmland, which comprises the following steps of: 1, selecting any point on the farmland to be detected as a starting point; 2, a carrying device is used for loading a ground penetrating radar to detect the starting point, in the detection process, the antenna frequency of the ground penetrating radar is dynamically selected according to the formation type of an ore deposit, the collection mode is dynamically adjusted according to the terrain gradient, the soil profile of the position of the starting point is obtained, and the thickness of a peat layer at the position is obtained according to the soil profile; 3, selecting a plurality of test points according to the thickness of the peat layer, and sequentially detecting the thickness of the peat layer at the position of each test point by using a ground penetrating radar; and 4, connecting the values of the peat layer thickness of the starting point and the peat layer thickness of the test point position to form a smooth curved surface so as to predict the peat layer thickness of other positions of the farmland. The method is used for reducing the influence of farmland grass roots and the like on data acquisition.

Description

Technical Field

[0001] The invention relates to the technical field of geophysical exploration, and in particular to a method for non-destructive detection of peat buried in farmland by radar. Background Art

[0002] Wetlands, as one of the most important ecosystems on Earth, play multiple roles, including biodiversity conservation, water resource regulation, and carbon storage and circulation. Peat wetlands, in particular, are not only efficient carbon sinks in nature, they can effectively absorb and store large amounts of carbon dioxide, slowing down the trend of global warming, but also have excellent water storage capacity, which is essential for maintaining regional hydrological and ecological balances. However, how to accurately and non-destructively assess the carbon sequestration and water storage capacity of wetlands has always been a key issue that scientists and industry management departments need to solve.

[0003] Traditional methods for assessing wetland carbon sequestration and water storage capacity often rely on field sampling and laboratory analysis, which is not only time-consuming and laborious, but may also cause a certain degree of damage to the wetland ecosystem. Therefore, it is particularly important to seek a non-invasive, efficient and accurate detection technology. Ground penetrating radar technology came into being in this context and has gradually become an important tool in the field of wetland research.

[0004] Ground penetrating radar is a non-destructive instrument that uses high-frequency electromagnetic wave signals to detect the distribution of underground media. Its working principle is based on the reflection, transmission and refraction of electromagnetic waves at the interface of different media. When the radar antenna transmits electromagnetic waves underground, these signals will be reflected when they encounter the interface of different media, and the reflected electromagnetic waves are captured and recorded by the receiving antenna. By analyzing the motion characteristics of these reflected signals, such as time difference and electromagnetic wave speed, the depth of the reflector from the surface can be accurately calculated, and then the structure and distribution of the underground medium can be detected.

[0005] In wetland detection, ground penetrating radar technology can clearly reveal the distribution and thickness information of the peat layer. Peat soil is a kind of soil with special properties. The thickness of its peat layer is usually more than 50 cm, and it is mostly distributed in low-lying areas in cold and humid areas. The mineral latent layer is often close to the peat layer, and sometimes there is a humus transition layer. During the detection process, ground penetrating radar can clearly distinguish the different reflection characteristics of the grass root layer, peat layer and mineral latent layer. The radar image of the grass root layer appears to be more scattered due to the presence of grass roots and other objects; while the peat layer, due to its low density and the presence of incompletely decomposed plant residues, presents completely different image characteristics from the grass root layer and the mineral latent layer.

[0006] However, due to the influence of grass roots on the ground, abnormal data is likely to appear during the detection process, thus affecting the judgment of the overall data. Summary of the invention

[0007] To solve the above problems, the present invention provides a method for non-destructively detecting buried peat in farmland by radar, which is used to reduce the influence of grass roots in farmland on data collection.

[0008] To achieve the above object, the technical solution of the present invention is as follows: A method for non-destructively detecting buried peat in farmland by radar, comprising the following steps: Step 1: Select any point on the farmland to be measured as the starting point; Step 2: Use a carrying device to load a ground penetrating radar to detect the starting point. During the detection process, dynamically select the antenna frequency of the ground penetrating radar according to the genetic type of the ore deposit, and dynamically adjust the acquisition method according to the terrain slope to obtain the soil profile at the starting point position, and obtain the peat layer thickness at this position according to the soil profile; Step 3: Select several test points according to the peat layer thickness, and use a ground penetrating radar to detect the peat layer thickness at the positions of each test point in turn; Step 4: Connect the numerical values of the peat layer thickness at the starting point and the peat layer thickness at the positions of the test points into a smooth surface, so as to predict the peat layer thickness at other positions in the farmland.

[0009] Further, when selecting the starting point in Step 1 and selecting the test points in Step 3, obtain the GPS position of the starting point or the test points, and adjust the data on the surface in Step 4 in combination with the GPS position.

[0010] Further, in Step 1, before selecting the starting point, collect the soil physical and chemical parameters, peat type and genetic type of the ore deposit of the farmland to be measured, and obtain a detection plan according to the soil physical and chemical parameters, peat type and genetic type of the ore deposit. The detection plan includes the selection of a ground penetrating radar and the selection of a detection season.

[0011] Further, the soil physical and chemical parameters in Step 1 include volumetric water content, organic matter content, density, pH value and degree of decomposition.

[0012] Further, the peat types in Step 1 include herbaceous, moss and woody mixed types.

[0013] Further, the genetic types of the ore deposit in Step 1 include recorded peat layers, mineral deposition layers and transition layers.

[0014] Further, in Step 2, the selection method of the antenna frequency of the ground penetrating radar is as follows: When the thickness of the transition layer > 30 cm is detected, use a 250 MHz shielded antenna for 5-meter-depth detection; When the dielectric constant difference between the peat layer and the mineral deposition layer < 15%, switch to a 500 MHz shielded antenna and supplement it with soil volumetric water content data for wave velocity calibration.

[0015] Further, in Step 2, when the ground penetrating radar is applied to a detection area with a terrain slope > 8°, GPS coordinate dot matrix detection is adopted to synchronously collect ground three-dimensional coordinate data. The two-way travel time data of the radar reflected wave is coupled with the terrain elevation data to establish a terrain compensation model to correct the peat layer thickness surface. The specific compensation formula is: where, is the compensated thickness, is the measured thickness, is the elevation difference between adjacent points, R is the propagation radius of electromagnetic waves in the peat layer, is the terrain inclination angle.

[0016] Further, in Step 3, the test points are evenly arranged.

[0017] Further, in Step 4, a multi-layer signal feature comparison mechanism is embedded in the surface generation process: a high-frequency filtering threshold of 20 - 35 MHz is set for the grass root layer reflection signal, an amplitude attenuation coefficient of < 10% is applied to the mineral gley layer reflection signal. When the peat layer reflection wave shows a double-peak feature within a time window of 0.5 - 1.2 ns, the decomposition parameter is started for layer thickness weighted calculation, and the weighting factor W = 1 + 0.05×(D - 40), where D is the decomposition index value measured in Step 1.

[0018] The above scheme has the following beneficial effects: 1. In this scheme, by detecting the thickness of the peat layer at different positions in the farmland and combining with the detection position coordinates, the thickness of the peat layer at other positions in the farmland is predicted, and then the reserve of the peat layer is estimated according to the plot area and the peat layer thickness. Compared with the prior art, this scheme is less affected by surface grass roots, etc., and has a higher accuracy. At the same time, since this scheme uses the method of collecting and predicting the overall data at points, fewer positions need to be collected, which is conducive to reducing the time required for preliminary investigation work. At the same time, this scheme obtains the best detection plan by obtaining data such as soil physical and chemical parameters, peat type, and ore deposit genetic type of the farmland to be detected, further improving the accuracy and effectiveness of detection.

[0019] 2. In this scheme, the antenna frequency of the ground penetrating radar is dynamically selected according to the ore deposit genetic type, which can ensure the best reflection effect of electromagnetic waves at the interface of different media. For example, when the transition layer is thick, a 250 MHz shielded antenna is selected for deep detection, and when the dielectric constant difference between the peat layer and the mineral deposition layer is small, a 500 MHz shielded antenna is used and the wave velocity is calibrated with the soil volume water content data to improve the accuracy and precision of detection.

[0020] 3. In this solution, GPS coordinate dot matrix detection is adopted in the detection area with a large terrain slope, and the ground three-dimensional coordinate data is collected synchronously. The thickness surface of the peat layer is corrected through the terrain compensation model. This approach can effectively overcome the influence of the terrain slope on the detection result and ensure accurate peat layer thickness data can be obtained under different terrain conditions.

[0021] 4. In this solution, a multi-layer signal feature comparison mechanism is embedded during the surface generation process, and targeted processing is performed on the reflection signals of the grass root layer, mineral gley layer, and peat layer. For example, a high-frequency filtering threshold is set for the reflection signal of the grass root layer, an amplitude attenuation coefficient is applied to the reflection signal of the mineral gley layer, and the decomposition degree parameter is activated according to the double-peak feature of the reflection wave of the peat layer for layer thickness weighted calculation, etc. These measures can further reduce the influence of surface grass roots, etc. on data collection and improve the accuracy and reliability of the detection result.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the method steps of an embodiment of the method for non-destructively detecting buried peat in farmland by radar of the present invention; Figure 2 It is a front view schematic diagram of the carrying device of an embodiment of the method for non-destructively detecting buried peat in farmland by radar of the present invention; Figure 3 It is a side sectional view schematic diagram of the carrying device of an embodiment of the method for non-destructively detecting buried peat in farmland by radar of the present invention.

[0024] Reference numerals in the accompanying drawings of the specification include: 1, wheel; 2, base; 3, ground penetrating radar; 4, support rod; 5, motor box; 6, push handle; 7, support seat; 8, vehicle frame; 9, main shaft; 10, universal connecting rod; 11, connecting rod; 12, adjusting shaft; 13, turbine blade; 14, blade; 15, airbag cavity; 16, piston rod; 17, second piston block; 18, oil chamber; 19, hydraulic chamber; 20, first piston block; 21, air chamber; 22, spring; 23, air delivery pipe; 24, first inclined rod. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", "connection" 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 circumstances.

[0028] The following is a further detailed description through specific embodiments: Embodiment 1: As shown in the Figure 1 accompanying drawings: A method for non-destructive detection of buried peat in farmland by radar includes the following steps: Step 1: Select any point on the farmland to be measured as the starting point; Step 2: Use the carrier device to load the ground-penetrating radar 3 to detect the starting point. During the detection process, dynamically select the antenna frequency of the ground-penetrating radar 3 according to the genetic type of the ore deposit, and dynamically adjust the acquisition method according to the terrain slope to obtain the soil profile at the starting point position, and obtain the peat layer thickness at this position according to the soil profile; Step 3: Select several test points according to the peat layer thickness, and use the ground-penetrating radar 3 to detect the peat layer thickness at the positions of each test point in turn; Step 4: Connect the values of the peat layer thickness at the starting point and the peat layer thickness at the positions of the test points into a smooth surface. The x-axis and y-axis in this surface are the position coordinates of the starting point and the test points respectively, and the z-axis is the peat layer thickness data, so as to predict the peat layer thickness at other positions of the farmland. According to the peat layer thickness at each position and the area of the farmland, the approximate reserve of the peat layer in this farmland can be calculated.

[0029] In this embodiment, when selecting the starting point in Step 1 and selecting the test points in Step 3, obtain the GPS position of the starting point or the test points, and adjust the data on the surface in combination with the GPS position in Step 4.

[0030] Since the thickness of the transition layer directly affects the attenuation gradient of electromagnetic waves and the difference in dielectric constants determines the reflection intensity at the layer interface, in this embodiment, the antenna frequency selection method of the ground penetrating radar 3 in step 2 is as follows: when it is detected that the thickness of the transition layer > 30 cm, a 250 MHz shielded antenna is used for 5-meter-depth detection; when the difference in dielectric constants between the peat layer and the mineral deposition layer < 15%, a 500 MHz shielded antenna is used and the wave velocity is calibrated with the soil volumetric water content data, which can effectively eliminate the time-depth conversion error caused by the mixing of organic matter-mineral components.

[0031] Due to the complex farmland environment, there are inevitably very rough or densely bushy places on the ground. If the selected test point location cannot be used for cross-section detection, for example, as described in step 2, when the ground penetrating radar 3 is applied to a detection area with a terrain slope > 8°, GPS coordinate dot matrix detection is used to synchronously collect the three-dimensional ground coordinate data, and the two-way travel time data of the radar reflected wave is coupled with the terrain elevation data to establish a terrain compensation model to correct the peat layer thickness surface. The specific compensation formula is: where, is the compensated thickness, is the measured thickness, is the elevation difference between adjacent points, R is the propagation radius of electromagnetic waves in the peat layer, is the terrain inclination angle. At this time, through the GPS technology, the GPS position data of the test point is obtained, which is beneficial to obtaining a more accurate plot area, thereby improving the accuracy of peat layer detection.

[0032] In this embodiment, the test points in step 3 are evenly arranged. The evenly arranged test points are beneficial to improving the representativeness of the collected data and reducing the peat layer calculation error caused by data mutation, etc.

[0033] Embodiment 2: As shown in the appendix Figure 1 The difference from Embodiment 1 is that in this embodiment, based on the past peat mining records of farmland, according to the correlation between various characteristics in the farmland and the signal quality obtained by the ground penetrating radar 3 during the pre-mining detection process, a peat detection plan planning model is constructed using the Dobson model. In step 1, before selecting the starting point, the soil physical and chemical parameters, peat type, and ore deposit genetic type of the farmland to be measured are collected, and a detection plan is generated according to the soil physical and chemical parameters, peat type, ore deposit genetic type, and the peat detection plan planning model. The detection plan includes the selection of the ground penetrating radar 3 and the selection of the detection season.

[0034] In this embodiment, the soil physical and chemical parameters in step 1 include volumetric water content, organic matter content, density, pH value, and degree of decomposition.

[0035] In this embodiment, the peat types in step 1 include mixed types of herbs, mosses and woody plants.

[0036] In this embodiment, the deposit genesis type in step 1 includes recorded peat layer, mineral sedimentary layer and transition layer.

[0037] Compared with the existing technology, this scheme effectively reduces the blindness of GPR parameter selection by generating a detection plan, clarifies the optimal detection parameters and time windows for different regions and seasons, and significantly improves the reliability and resolution of detection data. The scheme not only reduces the detection cost, but also provides standardized technical support for large-scale peat resource exploration, with significant economic benefits and engineering practicality.

[0038] Embodiment 3: As attached Figure 1 As shown, the difference from Example 2 is that due to the high-frequency interference (main frequency 40-60MHz) generated by the grass root layer of farmland, the sudden change of the reflection coefficient of the mineral latent layer causes artifacts, and the difference in peat decomposition degree causes nonlinear deviation of the wave velocity, therefore, in step 4, a multi-layer signal feature comparison mechanism is embedded in the surface generation process: a 20-35MHz high-frequency filter threshold is set for the grass root layer reflection signal to suppress the interference of the grass root layer; an amplitude attenuation coefficient of <10% is applied to the mineral latent layer reflection signal to eliminate the mineral layer artifacts; when the peat layer reflection wave shows a double peak feature within the time window of 0.5-1.2ns, the resolution parameter is started to perform layer thickness weighted calculation, and the weighting factor W=1+0.05×(D-40), where D is the resolution index value measured in step 1.

[0039] Embodiment 4: As attached Figure 2 and Figure 3 As shown, the difference from Example 3 is that in step 2, the carrying device includes a carrying vehicle. Since it is necessary to travel in the farmland during field detection using the ground penetrating radar 3, and since the ridges of the farmland are uneven, the carrying vehicle includes a base 2, a frame 8 and a plurality of wheels 1. The frame 8 is welded to the bottom of the base 2. Adaptive components for adaptive adjustment according to the terrain are provided at the front and rear of the frame 8. Both ends of the adaptive components are fixedly connected to the wheels 1. A cutting component for cutting off the grass roots wrapped around the wheel 1 is provided on the side of the wheel 1 away from the adaptive component, and the cutting component is connected to the adaptive component.

[0040] The ground penetrating radar 3 is detachably connected to the bottom of the vehicle frame 8. A push handle 6 is integrally formed on the base 2. A support rod 4 is hinged to one side of the base 2 close to the advancing direction of the carrier vehicle. A support seat 7 is provided between the end of the support rod 4 away from the base 2 and the push handle 6. The support seat 7 is used to place the mobile receiver. The mobile receiver is electrically connected to the ground penetrating radar 3. An adjustment assembly is provided at the connection between the support rod 4 and the support seat 7 for adjusting the angle of the support seat 7 to maintain the stability of the mobile receiver.

[0041] When encountering a ridge or a gully, it is not easy for the carrier vehicle to pass through. It is necessary to disassemble the ground penetrating radar 3 from the carrier vehicle and drag it. The detection signal is transmitted to the mobile receiver by wireless transmission, such as a laptop computer. However, in places with weak signals, wireless transmission is often inferior to the direct signal transmission of electrical connection, which may cause the signal transmitted by the ground penetrating radar 3 to be distorted. At the same time, forcibly pushing the carrier vehicle may cause the vehicle body to tilt and then lead to the distortion of the data of the ground penetrating radar 3. Therefore, the adaptation assembly includes main shafts 9 rotatably connected to both sides of the front and rear of the vehicle frame 8. One end of each main shaft 9 away from the vehicle frame 8 is hinged with a universal link 10. One end of each universal link 10 away from the main shaft 9 is integrally formed with a connecting rod 11. One end of each connecting rod 11 away from the universal link 10 is welded to the wheel 1. The terrain changes are transmitted through the universal link 10 and the connecting rod 11, so that the wheel 1 drives the carrier vehicle to move.

[0042] In the case of terrain undulation, elastic mechanisms are hinged to the connecting rods 11. Each elastic mechanism includes a first inclined rod 24 hinged to the bottom of the vehicle frame 8. An air chamber 21 is provided on the first inclined rod 24. The outlet of the air chamber 21 is connected to the cutting assembly through a one-way valve. A hydraulic chamber 19 is provided on the side of the air chamber 21 away from the first inclined rod 24. A first piston block 20 is provided between the hydraulic chamber 19 and the air chamber 21. A second piston block 17 is slidably connected in the hydraulic chamber 19. The second piston block 17 divides the interior of the hydraulic chamber 19 into an oil chamber 18 and a compression chamber. A piston rod 16 is welded to the side of the second piston block 17 located in the compression chamber. One end of the piston rod 16 away from the second piston block 17 penetrates through the compression chamber and extends to the outside and is hinged to the connecting rod 11. A spring 22 is welded between the piston rod 16 and the vehicle frame 8. When it is necessary to cross a ridge, the height difference of the farm ridge or gully may cause the wheel 1 to get stuck. The operator actively presses down the push handle 6 to lift the wheel 1 in front of the carrier vehicle over the obstacle. When the wheel 1 lands after being lifted, the wheel 1 is first squeezed by the external ground due to the gravity of the fall and receives an upward force. The universal link 10 moves upward together with the wheel 1. At this time, the connecting rod 11 compresses the second piston block 17 in the hydraulic chamber 19 through the piston rod 16. The oil in the oil chamber 18 buffers the vibration of the base 2 and the vehicle frame 8 of the carrier vehicle through the damping effect, so that the ground penetrating radar 3 and the mobile receiver can operate as smoothly as possible. The spring 22 provides a restoring force after the wheel 1 crosses the obstacle to assist the wheel 1 in resetting and successfully crosses the ridge.

[0043] And each time the wheel 1 passes over a ridge or a gully, while the oil chamber 18 is being squeezed, the oil squeezes the first piston block 20, and the gas in the air chamber 21 is squeezed into the cutting component. The cutting component includes an airbag chamber 15 adhesively connected to the side of the wheel 1 away from the connecting rod 11. A pressure valve is provided in the airbag chamber 15. The pressure valve is signal-connected to a controller. An air pipe 23 is connected between the pressure valve and the air chamber 21. The air pipe 23 is of a corrugated pipe structure. The compressed gas output from the air chamber 21 enters the airbag chamber 15 through the air pipe 23. The gas continuously stores gas in the airbag chamber 15 during the process of the carrier vehicle crossing the ridge and the gully. When the gas in the airbag chamber 15 reaches the threshold value, the controller controls the pressure valve to open. The other side of the pressure valve is rotatably connected to a rotating shaft. A plurality of turbine blades 13 are integrally formed on the rotating shaft. Blades 14 are welded on the turbine blades 13. The gas instantaneously released by the pressure valve impacts the turbine blades 13 to rotate, driving the blades 14 to cut the grass roots wound around the wheel 1 at a high speed, thereby avoiding parking for cleaning and improving the detection efficiency.

[0044] Embodiment 5: As shown in the attached Figure 2 and Figure 3 figure, the difference from Embodiment 4 is that an angle sensor is screw-connected to the rotating shaft. The angle sensor is signal-connected to the controller. When the carrier vehicle crosses the ridge and the gully, the air chamber 21 will convey gas to the airbag chamber 15, thereby driving the rotating shaft to rotate for weeding. At the same time, the angle sensor located on the rotating shaft can monitor the rotation angle in real time to judge whether the carrier vehicle is in a state of uneven terrain at this time. Since pushing the carrier vehicle forward when the terrain is uneven may cause the mobile receiving end on the support seat 7 to fall, and at the same time, it will also cause the operator's line-of-sight angle to be uneven with the mobile receiving end, and it is impossible to observe the transmission signal of the ground-penetrating radar 3 in time. Therefore, when the vehicle body tilts forward and the support seat 7 naturally presses down, the angle sensor detects the angle change of the rotating shaft, transmits a signal through the controller and starts the adjustment component. The adjustment component includes a motor box 5 welded at the connection between the support rod 4 and the support seat 7. A servo motor is provided in the motor box 5. The servo motor is signal-connected to the controller. The output shaft of the servo motor is coaxially welded with an adjustment shaft 12. A connecting piece is coaxially sleeved on the adjustment shaft 12. The connecting piece is fixedly connected to the support seat 7. The controller instructs the servo motor to rotate the adjustment shaft 12 in the reverse direction, driving the support seat 7 to lift up by 10°, keeping the screen of the mobile receiving end horizontal, and the operator can continuously observe the radar data interface without manual adjustment.

[0045] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or alterations derived therefrom still fall within the protection scope of the present invention.

Claims

1. A method for non-destructively detecting buried peat in farmland by radar, characterized in that, It includes the following steps: Step 1: Select any point on the farmland to be measured as the starting point; Step 2: Use the carrying device to load the ground penetrating radar (3) to detect the starting point. During the detection process, dynamically select the antenna frequency of the ground penetrating radar (3) according to the genetic type of the ore deposit, and dynamically adjust the acquisition method according to the terrain slope to obtain the soil profile at the starting point position, and obtain the peat layer thickness at this position according to the soil profile; Step 3: Select several test points according to the peat layer thickness, and use the ground penetrating radar (3) to detect the peat layer thickness at the positions of each test point in turn; Step 4: Connect the values of the peat layer thickness at the starting point and the peat layer thickness at the positions of the test points into a smooth surface, so as to predict the peat layer thickness at other positions of the farmland.

2. The method for non-destructively detecting buried peat in farmland by radar according to claim 1, wherein When selecting the starting point in Step 1 and selecting the test points in Step 3, obtain the GPS position of the starting point or the test points, and adjust the data on the surface in combination with the GPS position in Step 4.

3. The method for non-destructively detecting buried peat in farmland by radar according to claim 2, wherein In Step 1, before selecting the starting point, collect the soil physical and chemical parameters, peat type and genetic type of the ore deposit of the farmland to be measured, and obtain the detection plan according to the soil physical and chemical parameters, peat type and genetic type of the ore deposit. The detection plan includes the selection of the ground penetrating radar (3) and the selection of the detection season.

4. The method for non-destructively detecting buried peat in farmland by radar according to claim 3, characterized in that, The soil physical and chemical parameters in Step 1 include volumetric water content, organic matter content, density, pH value and degree of decomposition.

5. The method for non-destructively detecting buried peat in farmland by radar according to claim 4, characterized in that, The peat types in Step 1 include herbaceous, moss and woody mixed types.

6. The method for non-destructively detecting buried peat in farmland by radar according to claim 5, wherein, The genetic types of the ore deposit in Step 1 include recorded peat layer, mineral sediment layer and transition layer.

7. The method for non-destructively detecting buried peat in farmland by radar according to claim 6, characterized in that, In Step 2, the antenna frequency selection method of the ground penetrating radar (3) is as follows: when the thickness of the transition layer is detected to be > 30 cm, use a 250 MHz shielded antenna for 5-meter deep detection; when the dielectric constant difference between the peat layer and the mineral sediment layer is < 15%, switch to a 500 MHz shielded antenna and calibrate the wave velocity with the soil volumetric water content data.

8. The method for non-destructively detecting buried peat in farmland by radar according to claim 7, characterized in that, In Step 2, when the ground penetrating radar (3) is applied to the detection area with a terrain slope > 8°, use GPS coordinate dot matrix detection, synchronously collect the ground three-dimensional coordinate data, couple and calculate the two-way travel time data of the radar reflection wave and the terrain elevation data, and establish a terrain compensation model to correct the peat layer thickness surface. The specific compensation formula is: Among them, is the compensated thickness, is the measured thickness, is the elevation difference between adjacent points, and R is the propagation radius of electromagnetic waves in the peat layer, is the terrain inclination angle.

9. The method for non-destructively detecting buried peat in farmland by radar according to claim 8, wherein The test points in Step 3 are evenly arranged.

10. The method for non-destructively detecting buried peat in farmland by radar according to claim 9, characterized in that, In Step 4, a multi-layer signal feature comparison mechanism is embedded during the surface generation process: set a high-frequency filtering threshold of 20 - 35 MHz for the reflection signal of the grass root layer, apply an amplitude attenuation coefficient of < 10% to the reflection signal of the mineral gley layer, and when the peat layer reflection wave shows a double-peak feature within a 0.5 - 1.2 ns time window, start the degree of decomposition parameter for layer thickness weighted calculation, and the weighting factor W = 1 + 0.05×(D - 40), where D is the degree of decomposition index value measured in Step 1.

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