Corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device and verification method

Abstract

A corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device and verification method. The device comprises: a base (10), provided in a deformation area to be measured; a corner reflector (50), located above the base (10); a Z-axis driving part (20), a first end thereof being connected to the base (10), a second end thereof being connected to the corner reflector (50), and the Z-axis driving part (20) being used for driving the corner reflector (50) to move in a Z-axis direction; and an X-Y-axis driving part (30). The X-Y-axis driving part (30) is driven by a lever, so as to amplify the displacement of an operating end; the Z-axis driving part (20) is driven in a hydraulic manner, so as to reduce the longitudinal space of the driving parts, thus allowing for a compact structure with better wind resistance. In addition, by means of a displacement feedback part, the adjustment displacement of the corner reflector (50) is accurately measured at the sub-millimeter accuracy, thereby ensuring the validity and reliability of the synthetic aperture radar interferometric accuracy verification.

Description

Synthetic aperture radar deformation monitoring accuracy verification device and verification method based on corner reflector Technical Field

[0001] The present invention relates to the field of radar monitoring technology, and in particular to a device and method for verifying the deformation monitoring accuracy of a synthetic aperture radar based on a corner reflector. Background Art

[0002] Artificial corner reflector differential interferometry is a time-series deformation monitoring method based on the artificial placement of highly coherent, strongly reflective target points. It is often used to address the difficulty in extracting effective measurement points in low-coherence areas covered by vegetation and to verify the accuracy of synthetic aperture radar interferometry (InSAR) monitoring results. The backscatter intensity of corner reflectors (CRs) is much greater than that of surrounding objects, appearing as distinct bright spots on synthetic aperture radar (SAR) images. These CRs can be effectively extracted, and their phase changes can be used to obtain highly accurate deformation information.

[0003] When the deformation of the monitored area is relatively stable, there is no obvious deformation at each corner reflector (CR) point. However, in order to verify the monitoring capability of synthetic aperture radar interferometry (InSAR), it is necessary to manually and actively adjust the positions of certain corner reflectors (CR) in a specific time period to verify the monitoring accuracy of corner reflector synthetic aperture radar interferometry (CR-InSAR).

[0004] Currently, the driving structure of a corner reflector is generally a screw transmission structure. For example, Patent Document 1 proposes using a three-screw transmission structure to control the pitch angle of the corner reflector. Patent Document 2 proposes using a three-axis micro-drive component to achieve manual fine-tuning of the corner reflector during field installation. However, the above patents can only achieve accurate alignment and installation of the corner reflector, and lack the ability to adjust the displacement of the corner reflector with sub-millimeter precision in three-axis directions, making it impossible to achieve precision verification of synthetic aperture radar interferometry based on artificial corner reflectors.

[0005] Prior art literature

[0006] Patent Document 1 CN105974368A A GNSS-DInSAR technology integrated corner reflector

[0007] Patent Document 2 CN109212490A Three-axis micro-motion artificial corner reflector

[0008] Summary of the Invention

[0009] In order to solve the technical problems existing in the accuracy verification of radar deformation detection in the prior art, the first aspect of the present invention proposes a synthetic aperture radar deformation monitoring accuracy verification device based on a corner reflector, comprising:

[0010] A base, arranged in a deformation area to be detected;

[0011] a corner reflector located above the base;

[0012] A Z-axis driving component, a first end of which is connected to the base, and a second end of which is connected to the corner reflector, wherein the Z-axis driving component is used to drive the corner reflector to move along the Z-axis direction;

[0013] An XY-axis driving component connected to the base, the XY-axis driving component is used to drive the corner reflector to move along the XY-axis direction;

[0014] a displacement feedback component connected to the base, the displacement feedback component being used to detect the displacement of the corner reflector relative to the base in the XYZ axis directions;

[0015] The displacement feedback component includes an XY-axis detection unit and a Z-axis detection unit connected to the base, and a trigger component connected to the corner reflector. The trigger component is configured to generate a first light beam and a second light beam. The Z-axis detection unit is used to detect the position of the first light beam in the Z-axis direction, and the XY-axis detection unit is used to detect the relative position of the second light beam in the XY plane.

[0016] The displacement feedback component also includes a displacement detection component. When the corner reflector is driven by the Z-axis driving component and the XY-axis driving component, the displacement detection component calculates the displacement of the corner reflector based on the displacement of the first light beam and the second light beam in the XYZ-axis direction detected by the XY-axis detection unit and the Z-axis detection unit.

[0017] Preferably, the XY-axis driving component includes an X-axis driving rod and a Y-axis driving rod, the base is provided with a rotating shaft, the X-axis driving rod and the Y-axis driving rod are both connected to the rotating shaft and can rotate around the rotating shaft, and the bottom of the corner reflector is provided with an X-axis limiting channel and a Y-axis limiting channel;

[0018] The first end of the X-axis drive rod extends into the X-axis limit channel, and the second end extends outward of the corner reflector. The first end of the Y-axis drive rod extends into the Y-axis limit channel, and the second end extends outward of the corner reflector. The X-axis limit channel is configured to limit the displacement of the X-axis drive rod relative to the corner reflector in the X-axis direction, and the Y-axis limit channel is configured to limit the displacement of the Y-axis drive rod relative to the corner reflector in the Y-axis direction.

[0019] When the second end of the X-axis driving rod is operated to move in the X-axis direction, the corner reflector moves in the X-axis direction. When the second end of the Y-axis driving rod is operated to move in the Y-axis direction, the corner reflector moves in the Y-axis direction.

[0020] Preferably, the axis of the rotating shaft is parallel to the Z-axis, the X-axis drive rod and the Y-axis drive rod are arranged at different horizontal heights, and the X-axis limit channel and the Y-axis limit channel are arranged to limit the X-axis drive rod and the Y-axis drive rod within the entire Z-axis travel of the corner reflector.

[0021] Preferably, the X-axis driving rod and the Y-axis driving rod each include a rod body and a disc-shaped limiting structure at the first end of the rod body, and the width and length of the X-axis limiting channel or the Y-axis limiting channel are equal to the diameter of the disc-shaped limiting structure.

[0022] Preferably, the Z-axis driving component includes a first oil cylinder and at least one second oil cylinder, the diameter of the oil chamber in the second oil cylinder is larger than the diameter of the oil chamber in the first oil cylinder, the oil chamber of the first oil cylinder and the oil chamber of the second oil cylinder are connected through an oil pipe, the first oil cylinder is arranged in a direction perpendicular to the Z axis, and the second oil cylinder is arranged in a direction parallel to the Z axis, the two ends of the second oil cylinder are respectively connected to the base and the corner reflector, and the first oil cylinder is provided with a hand-cranked push rod. When the hand-cranked push rod rotates, the piston at one end of the hand-cranked push rod slides in the oil chamber of the first oil cylinder to control the extension and retraction of the second oil cylinder.

[0023] Preferably, the first end of the second oil cylinder is fixed to the corner reflector along the Z-axis direction, and the first end of the second oil cylinder slides relative to the corner reflector in the XY-axis direction.

[0024] Preferably, a limit frame is provided at the bottom of the corner reflector, a cross limit structure is provided at the first end of the second oil cylinder, four limit slots are provided in the limit frame, and the cross limit structure extends into the limit slot. When the corner reflector moves along the XY plane, the cross limit structure remains in contact with the limit slot. A limit platform is also provided at the bottom of the corner reflector, and the X-axis limit channel and the Y-axis limit channel are formed between the limit platform and the limit frame.

[0025] Preferably, the XY-axis detection unit is perpendicular to the Z-axis, the Z-axis detection unit is parallel to the Z-axis, the XY-axis detection unit includes a plurality of square optical fiber bundles closely distributed in a rectangular array, the Z-axis detection unit includes a plurality of rectangular optical fiber bundles closely arranged along the Z-axis direction, and the XY-axis detection unit and the Z-axis detection unit are in a closed and shielded space.

[0026] Preferably, the displacement detection component includes a photosensor, and the photosensor is arranged to correspond to each square optical fiber bundle and rectangular optical fiber bundle.

[0027] The second aspect of the present invention provides a technical solution, a method for verifying the accuracy of deformation monitoring based on a corner reflector, using the above-mentioned accuracy verification device, comprising the following steps:

[0028] Step 1: After the corner reflector is arranged, obtain the synthetic aperture radar interferometry measurement result based on the corner reflector. This result is the displacement result of the corner reflector along the radar satellite line of sight, recorded as result A;

[0029] Step 2: Control the corner reflector to move in a predetermined direction using the Z-axis drive component and / or the XY-axis drive component, and obtain the actual adjusted displacement of the corner reflector using the displacement feedback component. The resulting displacement of the corner reflector in the radar satellite line of sight is then calculated based on the X-axis or Y-axis azimuth (the angle with true north) and the satellite incidence angle.

[0030] Step 3: Obtain the corner reflector-based synthetic aperture radar interferometry measurement result again, which is recorded as result B;

[0031] Step 4: Obtain a measured displacement result based on result B and result A, compare the difference between the measured displacement result and the actual displacement true value, and calculate the mean error of the difference as an accuracy evaluation index of the corner reflector interferometry;

[0032] Wherein, in step 2, the spatial position of a single corner reflector is adjusted during different satellite monitoring periods.

[0033] Compared with the prior art, the advantages of the present invention are:

[0034] The XY-axis drive components provided in the present invention are driven by levers, which amplify the displacement of the operating end. The Z-axis drive components are driven by hydraulics. While amplifying the displacement of the operating end to ensure adjustment accuracy, the longitudinal space of the drive components is reduced, making the structure compact and having better wind resistance. The displacement of the corner reflector adjustment is accurately measured through the displacement feedback component to ensure the effectiveness and reliability of the synthetic aperture radar interferometry measurement accuracy verification. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For the sake of clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0036] FIG1 is a schematic structural diagram of a corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device according to the present invention;

[0037] FIG2 is a schematic structural diagram of the AA direction in FIG1;

[0038] FIG3 is a transmission schematic diagram of the Z-axis drive component shown in the present invention;

[0039] FIG4 is a schematic structural diagram of a displacement feedback component shown in the present invention;

[0040] FIG5 is a schematic structural diagram of an XY axis detection unit according to the present invention;

[0041] FIG6 is a schematic structural diagram of a Z-axis detection unit according to the present invention;

[0042] FIG7 is a schematic diagram showing how the spatial displacement of the corner reflector shown in the present invention is converted into displacement in the line of sight of a radar satellite. DETAILED DESCRIPTION

[0043] In order to better understand the technical content of the present invention, specific embodiments are given and described below with reference to the accompanying drawings.

[0044] In order to verify the monitoring capability of synthetic aperture radar interferometry (InSAR), it is necessary to manually and actively adjust the positions of certain corner reflectors (CR) during a specific time period to verify the monitoring capability of corner reflector-based synthetic aperture radar interferometry (CR-InSAR). The displacement adjustment accuracy of the corner reflector is the basis for verifying the accuracy of synthetic aperture radar interferometry. If the adjustment displacement of the corner reflector has an error from the ideal value, the measurement accuracy cannot be effectively verified. Therefore, this application aims to accurately control the corner reflector so that it can be manually adjusted to the ideal position to ensure the effectiveness and reliability of synthetic aperture radar interferometry accuracy verification.

[0045] [Synthetic aperture radar deformation monitoring accuracy verification device based on corner reflector]

[0046] As shown in Figure 1, the first aspect of the present invention proposes a synthetic aperture radar deformation monitoring accuracy verification device based on a corner reflector, including a base 10, a corner reflector 50, a Z-axis driving component 20, an XY-axis driving component 30 and a displacement feedback component 40.

[0047] The base 10 is set in the deformation area to be detected. The base 10 can be formed by pouring concrete as a solid foundation. The corner reflector 50 is above the base 10. The Z-axis drive component 20 and the XY-axis drive component 30 are set between the corner reflector 50 and the base 10. The first end of the Z-axis drive component 20 is connected to the base 10, and the second end is connected to the corner reflector 50. The Z-axis drive component 20 is used to drive the corner reflector 50 to move along the Z-axis direction. The XY-axis drive component 30 is connected to the base 10. The XY-axis drive component 30 is used to drive the corner reflector 50 to move along the XY-axis direction.

[0048] The Z-axis drive component 20 is driven by a hydraulic cylinder, and the XY-axis drive component 30 is driven by a lever, which can compress the three-axis drive structure into a smaller vertical space. Therefore, compared with the traditional gantry drive device, it is smaller in size and has better wind resistance.

[0049] As shown in Figures 1-2, the XY-axis driving component 30 includes an X-axis driving rod 32 and a Y-axis driving rod 31. A rotating shaft 301 is provided on the base 10. The X-axis driving rod 32 and the Y-axis driving rod 31 are both connected to the rotating shaft 301 and can rotate around the rotating shaft 301. The bottom of the corner reflector 50 is provided with an X-axis limiting channel 323 and a Y-axis limiting channel 313.

[0050] Furthermore, the first end of the X-axis drive rod 32 extends into the X-axis limit channel 323, and the second end extends toward the outside of the corner reflector 50. The first end of the Y-axis drive rod 31 extends into the Y-axis limit channel 313, and the second end extends toward the outside of the corner reflector 50. The X-axis limit channel 323 is configured to limit the displacement of the X-axis drive rod 32 in the X-axis direction relative to the corner reflector 50, and the Y-axis limit channel 313 is configured to limit the displacement of the Y-axis drive rod 31 in the Y-axis direction relative to the corner reflector 50.

[0051] As shown in Figure 2, the first end of the X-axis driving rod 32 extends into the X-axis limiting channel 323. When the second end of the X-axis driving rod 32 is operated to rotate the X-axis driving rod 32 around the rotating shaft 301, the first end of the X-axis driving rod 32 generates a thrust on the inner wall of the X-axis limiting channel 323, that is, controls the corner reflector 50 to move in the first direction or the second direction of the X-axis. Similarly, the first end of the Y-axis driving rod 31 extends into the Y-axis limiting channel 313. When the second end of the Y-axis driving rod 31 is operated to rotate the Y-axis driving rod 31 around the rotating shaft 301, the first end of the Y-axis driving rod 31 generates a thrust on the inner wall of the Y-axis limiting channel 313, that is, controls the corner reflector 50 to move in the first direction or the second direction of the Y-axis.

[0052] In an optional embodiment, the maximum distance that the corner reflector 50 can move in the XYZ axis direction is 20-30 mm.

[0053] In this way, when the second end of the X-axis driving rod 32 is operated to move in the X-axis direction, the corner reflector 50 moves in the X-axis direction, and when the second end of the Y-axis driving rod 31 is operated to move in the Y-axis direction, the corner reflector 50 moves in the Y-axis direction. By controlling the movement amount of the second end of the X-axis driving rod 32 or the Y-axis driving rod 31, the corner reflector 50 can achieve a suitable horizontal displacement.

[0054] Furthermore, in order to prevent the X-axis drive rod 32 and the Y-axis drive rod 31 from interfering with each other during rotation, the axis of the rotating shaft 301 is parallel to the Z-axis, the X-axis drive rod 32 and the Y-axis drive rod 31 are set at different horizontal heights, and the X-axis limit channel 323 and the Y-axis limit channel 313 are set to limit the X-axis drive rod 32 and the Y-axis drive rod 31 within the entire Z-axis travel of the corner reflector 50.

[0055] In this way, when the corner reflector 50 is driven to move up and down by the Z-axis driving component 20 , the X-axis driving rod 32 and the Y-axis driving rod 31 can still control the corner reflector 50 to move along the X and Y axes.

[0056] Preferably, the X-axis drive rod 32 and the Y-axis drive rod 31 both include a rod body and a disc-shaped limiting structure at the first end of the rod body, and the width and length of the X-axis limiting channel 323 or the Y-axis limiting channel 313 are equal to the diameter of the disc-shaped limiting structure, wherein the diameter of the disc-shaped limiting structure is 20-30 mm.

[0057] Specifically, the Y-axis driving rod 31 includes a first rod shaft 311 and a first disc-shaped limiting structure 312, and the X-axis driving rod 32 includes a second rod shaft 321 and a second disc-shaped limiting structure 312. The other ends of the first rod shaft 311 and the second rod shaft 321 are ring structures.

[0058] In an optional embodiment, the ratio of the length of the first rod body 311 and the rotating shaft 301 at the hinge side close to the first disc-shaped limiting structure 312 to the length at the ring structure side is greater than 5:1, and the ratio of the length of the second rod body 321 and the rotating shaft 301 at the hinge side close to the second disc-shaped limiting structure 312 to the length at the ring structure side is greater than 5:1. In this way, the X-axis drive rod 32 and the Y-axis drive rod 31 form a force-saving lever, which makes it easier and more accurate to control the displacement of the corner reflector 50 during operation.

[0059] In this way, after the X-axis driving rod 32 and the Y-axis driving rod 31 are adjusted to appropriate positions, the relative positions of the X-axis driving rod 32 and the Y-axis driving rod 31 are fixed to the base 10 through the fastening device, so that the corner reflector 50 is stabilized in the adjusted position state.

[0060] As shown in Figures 2-3 , the Z-axis drive assembly 20 includes a first cylinder 21 and at least one second cylinder. The oil chamber in the second cylinder has a larger diameter than the oil chamber in the first cylinder 21. The oil chambers of the first and second cylinders are connected by an oil pipeline. This allows the first cylinder 21 to extend and retract more rapidly to control the extension and retraction of the second cylinder, enabling more precise control of the extension and retraction of the second cylinder.

[0061] In a specific embodiment, two second oil cylinders are provided, namely the left second oil cylinder 22 and the right second oil cylinder 23. The left second oil cylinder 22 and the right second oil cylinder 23 have the same structure, both including cylinder bodies 231, 221, telescopic rods 232, 222 and second oil chambers 202, 203. The diameter of the first oil chamber 201 of the first oil cylinder 21 is one third of the diameter of the second oil chambers 202, 203.

[0062] Furthermore, the first oil cylinder 21 is arranged in a direction perpendicular to the Z axis, and the second oil cylinder is arranged in a direction parallel to the Z axis.

[0063] In this way, the space occupied by the Z-axis driving component 20 in the Z-axis direction can be smaller, and the wind resistance can be improved.

[0064] Specifically, the second oil cylinder is connected to the base 10 and the corner reflector 50 at both ends. The first oil cylinder 21 is provided with a crank rod 211. When the crank rod 211 rotates, a piston at one end of the crank rod 211 slides within the oil chamber of the first oil cylinder 21, controlling the extension and retraction of the second oil cylinder. The front end of the crank rod 211 is provided with a handle 212.

[0065] When it is necessary to control the corner reflector 50 to rise, the hand-cranked push rod 211 is rotated clockwise to reduce the oil chamber space of the first oil cylinder 21 and increase the oil chamber space of the second oil cylinder, thereby lengthening the second oil cylinder. Conversely, when it is necessary to control the corner reflector 50 to fall, the hand-cranked push rod 211 is rotated counterclockwise to increase the oil chamber space of the first oil cylinder 21 and decrease the oil chamber space of the second oil cylinder, thereby shortening the second oil cylinder.

[0066] Furthermore, the first end of the second oil cylinder is fixed to the corner reflector 50 along the Z axis, and the first end of the second oil cylinder slides relative to the corner reflector 50 in the XY axis. In this way, when the corner reflector 50 moves along the Z axis, it can also move in the XY direction.

[0067] In a specific embodiment, as shown in Figure 2, a limit frame 52 is provided at the bottom of the corner reflector 50, a cross limit structure 223 is provided at the first end of the second oil cylinder, four limit slots are provided in the limit frame 52, and the cross limit structure 223 extends into the limit slot. When the corner reflector 50 moves along the XY plane, the cross limit structure 223 remains in contact with the limit slot.

[0068] In this way, when the corner reflector 50 moves in the XY plane, at least two limiting bars in the cross limiting structure 223 are located in the limiting grooves of the limiting frame 52, so that the corner reflector 50 and the second oil cylinder are fixed in the Z-axis direction.

[0069] In an optional embodiment, an adjustment platform 51 is provided at the bottom of the corner reflector 50, and a predetermined angle is formed between the adjustment platform 51 and the corner reflector 50 so that the elevation angle of the corner reflector 50 is at a predetermined angle. A limit platform 53 and a limit frame 52 are provided at the bottom of the adjustment platform 51, and an X-axis limit channel 323 and a Y-axis limit channel 313 are formed between the limit platform 53 and the limit frame 52.

[0070] The limiting platform 53 and the limiting frame 52 are both made of stainless steel.

[0071] As shown in Figure 4, the displacement feedback component 40 is connected to the base 10. The displacement feedback component 40 is used to detect the displacement of the corner reflector 50 in the XYZ axis direction compared to the base 10. In this way, the actual displacement of the corner reflector 50 driven by the Z-axis driving component 20 and the XY-axis driving component 30 can be intuitively reflected, avoiding errors in the transmission structure that cause the actual moving distance of the corner reflector 50 to be inconsistent with expectations.

[0072] Furthermore, in order to more accurately display the actual displacement of the corner reflector 50, especially to the sub-millimeter level, the displacement feedback component 40 includes an XY-axis detection unit 431 connected to the base 10, a Z-axis detection unit 432, and a trigger component 44 connected to the corner reflector 50. The trigger component 44 is configured to generate a first light beam 401 and a second light beam 402. The Z-axis detection unit 432 is used to detect the position of the first light beam 401 in the Z-axis direction, and the XY-axis detection unit 431 is used to detect the relative position of the second light beam 402 in the XY plane.

[0073] Specifically, a light source 441 and a light shielding cap 442 are provided at the front end of the trigger component 44. The light shielding cap 442 is provided with two holes through which the first light beam 401 and the second light beam 402 are emitted respectively.

[0074] Since the light beam can reach a thinner diameter, the light-transmitting areas are separated by the XY-axis detection unit 431 and the Z-axis detection unit 432 to form multiple independent light-transmitting areas with specific positions. Therefore, when the light beam is irradiated to the corresponding light-transmitting area, the position is a known position. Therefore, the displacement of the light beam in the XYZ-axis direction can be obtained by changing the position of light in different light-transmitting areas.

[0075] Furthermore, the displacement feedback component 40 also includes a displacement detection component 42. When the corner reflector 50 is driven by the Z-axis driving component 20 and the XY-axis driving component 30, the displacement detection component 42 calculates the displacement of the corner reflector 50 based on the displacement of the first light beam 401 and the second light beam 402 in the XYZ-axis direction detected by the XY-axis detection unit 431 and the Z-axis detection unit 432.

[0076] As shown in Figures 5 and 6, in an optional embodiment, the XY-axis detection unit 431 is perpendicular to the Z-axis, the Z-axis detection unit 432 is parallel to the Z-axis, the XY-axis detection unit 431 includes a plurality of square optical fiber bundles closely distributed in a rectangular array, and the Z-axis detection unit 432 includes a plurality of rectangular optical fiber bundles closely arranged along the Z-axis direction.

[0077] Specifically, the displacement feedback component 40 includes a shell 41, and the opening of the shell 41 is provided with a flexible light-shielding sleeve 45 connected to the adjustment platform. When the trigger component 44 is displaced, the XY-axis detection unit 431 and the Z-axis detection unit 432 are ensured to be in a closed and shielded space.

[0078] The optical fiber bundle is a light guide beam formed by multiple optical fibers arranged side by side, and each light guide beam is separated by a light-shielding material, so that adjacent light guide beams are independent of each other.

[0079] Furthermore, displacement detection component 42 includes photosensors, which are arranged to correspond to each square fiber bundle and rectangular fiber bundle. Displacement detection component 42 also includes a position calculation unit. The photosensors detect the area of ​​the light guide corresponding to the light beam. The position calculation unit identifies and calculates the position of each area to obtain the displacement of the light beam between the starting point and the end point.

[0080] In an optional embodiment, the size of the square optical fiber bundle is 0.5*0.5 mm, and the width of the rectangular optical fiber bundle is 0.5 mm. Therefore, the calculation accuracy of the position calculation unit can reach an accuracy of 0.5 mm.

[0081] In a preferred embodiment, an electrical switch and a display screen are provided on the outside of the housing 41 , and the display screen is used to display the calculation results of the displacement detection component 42 , including the displacement of the corner reflector 50 in the XYZ axis directions.

[0082] [Deformation monitoring accuracy verification method based on corner reflector]

[0083] The second aspect of the present invention provides a technical solution, a method for verifying the accuracy of deformation monitoring based on a corner reflector, using the above-mentioned accuracy verification device, comprising the following steps:

[0084] Step 1: After the corner reflector is arranged, obtain the synthetic aperture radar interferometry measurement result based on the corner reflector. This result is the displacement result of the corner reflector along the radar satellite line of sight, recorded as result A;

[0085] Step 2: Control the corner reflector 50 to move in a predetermined direction via the Z-axis drive component 20 and / or the XY-axis drive component 30, and obtain the actual adjusted displacement of the corner reflector 50 via the displacement feedback component 40. Then, the resulting displacement of the corner reflector in the radar satellite line of sight is calculated based on the angle between the X-axis or Y-axis azimuth and the true north direction and the satellite incidence angle.

[0086] Step 3: Obtain the corner reflector-based synthetic aperture radar interferometry measurement result again, which is recorded as result B;

[0087] Step 4: Obtain a measured displacement result based on result B and result A, compare the difference between the measured displacement result and the actual displacement true value, and calculate the mean error of the difference as an accuracy evaluation index of the corner reflector interferometry;

[0088] In step 2, the spatial position of the single corner reflector 50 is adjusted during different satellite monitoring periods.

[0089] In a specific embodiment, two corner reflectors are arranged in the area to be detected, and the distance between the two corner reflectors is less than 50 meters. One of the corner reflectors is set to be fixed and its displacement is not adjusted. It serves as a reference body for the relative displacement of the second corner reflector. The second corner reflector adjusts different three-axis displacements in different monitoring periods. Finally, the difference between the displacement of the corner reflector in time series and that of satellite monitoring is compared, and the accuracy is calculated.

[0090] When the distance between the two corner reflectors is less than 50 meters, firstly, the influence of the naturally generated non-artificial displacement of the corner reflectors on the accuracy verification can be eliminated, and secondly, the error influence of the atmospheric phase on the synthetic aperture radar interferometry measurement results can be weakened.

[0091] As shown in Figure 7, Figure 7 shows that the synthetic aperture radar measurement result is the result of the one-dimensional LOS direction, which is equal to the vector sum of the projections of the north-south, east-west, and vertical displacements in the line of sight direction, that is, the displacement of the corner reflector in three-dimensional space is converted to the displacement in the aperture radar line of sight direction.

[0092] Specifically, the actual adjustment displacement of the corner reflector 50 obtained by the displacement feedback component 40 in step 2 is converted into the displacement result of the corner reflector in the line of sight of the radar satellite as the true value, and the difference between the synthetic aperture radar interferometry measurement results in step 3 and step 1 is the measured value. The error m0 in the difference between the true value and the measured value is an unbiased estimate as an indicator to verify the InSAR measurement accuracy.

[0093] The calculation formula for the mean error is:

[0094] Wherein, n is the number of samples, i.e., the number of displacement adjustments of the corner reflector 50;

[0095] dL i and dI i —are the true value and measured value corresponding to sample point i respectively.

[0096] According to multiple adjustments of the corner reflector at different times, multiple sets of true value and measured value data can be obtained. The mean error between the true value and the measured value is calculated by the above-mentioned mean error calculation formula to verify the displacement monitoring accuracy. Since the unit displacement of the corner reflector 50 can reach 0.5 mm, if the error result between the true value and the measured value is less than the preset value, it means that the synthetic aperture radar interferometry measurement accuracy based on the artificial corner reflector can reach the sub-millimeter level.

[0097] In combination with the above embodiments, the XY-axis drive component provided in the present invention is driven by a lever, which amplifies the displacement of the operating end, and the Z-axis drive component is driven by a hydraulic method. While amplifying the displacement of the operating end to ensure adjustment accuracy, the longitudinal space of the drive component is reduced, making the structure compact and having better wind resistance. The displacement of the corner reflector adjustment is accurately measured through the displacement feedback component, so that the ideal angle adjusted after the corner reflector is controlled is consistent with the actual angle, thereby ensuring the effectiveness and reliability of the synthetic aperture radar interferometry measurement accuracy verification.

[0098] While the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A synthetic aperture radar deformation monitoring accuracy verification device based on a corner reflector, characterized in that: include: A base (10) is arranged in a deformation area to be detected; A corner reflector (50) is located above the base (10); A Z-axis driving component (20), a first end of which is connected to the base (10) and a second end of which is connected to the corner reflector (50), the Z-axis driving component (20) being used to drive the corner reflector (50) to move along the Z-axis direction; An XY-axis driving component (30) connected to the base (10), the XY-axis driving component (30) being used to drive the corner reflector (50) to move along the XY-axis direction; a displacement feedback component (40) connected to the base (10), the displacement feedback component (40) being used to detect the displacement of the corner reflector (50) relative to the base (10) in the XYZ axis directions; The displacement feedback component (40) comprises an XY-axis detection unit (431) and a Z-axis detection unit (432) connected to the base (10), and a trigger component (44) connected to the corner reflector (50); the trigger component (44) is configured to generate a first light beam (401) and a second light beam (402); the Z-axis detection unit (432) is used to detect the position of the first light beam (401) in the Z-axis direction; and the XY-axis detection unit (431) is used to detect the relative position of the second light beam (402) in the XY plane. The displacement feedback component (40) further includes a displacement detection component (42). When the corner reflector (50) is driven by the Z-axis driving component (20) and the XY-axis driving component (30), the displacement detection component (42) calculates the displacement of the corner reflector (50) based on the displacements of the first light beam (401) and the second light beam (402) in the XYZ-axis directions detected by the XY-axis detection unit (431) and the Z-axis detection unit (432).

2. The corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device according to claim 1, characterized in that: The XY-axis driving component (30) comprises an X-axis driving rod (32) and a Y-axis driving rod (31); a rotating shaft (301) is provided on the base (10); the X-axis driving rod (32) and the Y-axis driving rod (31) are both connected to the rotating shaft (301) and can rotate around the rotating shaft (301); and an X-axis limiting channel (323) and a Y-axis limiting channel (313) are provided at the bottom of the corner reflector (50); The first end of the X-axis driving rod (32) extends into the X-axis limiting channel (323), and the second end extends toward the outside of the corner reflector (50); the first end of the Y-axis driving rod (31) extends into the Y-axis limiting channel (313), and the second end extends toward the outside of the corner reflector (50); the X-axis limiting channel (323) is configured to limit the displacement of the X-axis driving rod (32) relative to the corner reflector (50) in the X-axis direction; and the Y-axis limiting channel (313) is configured to limit the displacement of the Y-axis driving rod (31) relative to the corner reflector (50) in the Y-axis direction. When the second end of the X-axis driving rod (32) is operated to move in the X-axis direction, the corner reflector (50) moves in the X-axis direction, and when the second end of the Y-axis driving rod (31) is operated to move in the Y-axis direction, the corner reflector (50) moves in the X-axis direction. Move in the Y-axis direction.

3. The corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device according to claim 2, characterized in that: The axis of the rotating shaft (301) is parallel to the Z axis, the X axis driving rod (32) and the Y axis driving rod (31) are arranged at different horizontal heights, and the X axis limiting channel (323) and the Y axis limiting channel (313) are arranged to limit the X axis driving rod (32) and the Y axis driving rod (31) within the entire Z axis travel of the corner reflector (50).

4. The corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device according to claim 2, characterized in that: The X-axis driving rod (32) and the Y-axis driving rod (31) both comprise a rod body and a disc-shaped limiting structure at a first end of the rod body, and the width and length of the X-axis limiting channel (323) or the Y-axis limiting channel (313) are equal to the diameter of the disc-shaped limiting structure.

5. The corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device according to claim 2, characterized in that: The Z-axis driving component (20) includes a first oil cylinder (21) and at least one second oil cylinder. The diameter of the oil cavity in the second oil cylinder is larger than the diameter of the oil cavity in the first oil cylinder (21). The oil cavity of the first oil cylinder (21) and the oil cavity of the second oil cylinder are connected through an oil pipeline. The first oil cylinder (21) is arranged in a direction perpendicular to the Z-axis, and the second oil cylinder is arranged in a direction parallel to the Z-axis. The two ends of the second oil cylinder are respectively connected to the base (10) and the corner reflector (50). The first oil cylinder (21) is provided with a hand-cranked push rod (211). When the hand-cranked push rod (211) rotates, the piston at one end of the hand-cranked push rod (211) slides in the oil cavity of the first oil cylinder (21) to control the extension and contraction of the second oil cylinder.

6. The corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device according to claim 5, characterized in that: The first end of the second oil cylinder is fixed to the corner reflector (50) along the Z-axis direction, and the first end of the second oil cylinder slides relatively with respect to the corner reflector (50) in the XY-axis directions.

7. The device for verifying deformation monitoring accuracy of synthetic aperture radar based on corner reflector according to any one of claims 1 to 6, characterized in that: A limit frame (52) is provided at the bottom of the corner reflector (50), a cross limit structure (223) is provided at the first end of the second oil cylinder, four limit slots are provided in the limit frame (52), the cross limit structure (223) extends into the limit slots, and when the corner reflector (50) moves along the XY plane, the cross limit structure (223) remains in contact with the limit slots. A limit platform (53) is also provided at the bottom of the corner reflector (50), and the X-axis limit channel (323) and the Y-axis limit channel (313) are formed between the limit platform (53) and the limit frame (52).

8. The corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device according to claim 1, characterized in that: The XY-axis detection unit (431) is perpendicular to the Z-axis, and the Z-axis detection unit (432) is parallel to the Z-axis. The XY-axis detection unit (431) includes a plurality of square optical fiber bundles closely distributed in a rectangular array, and the Z-axis detection unit (432) includes a plurality of rectangular optical fiber bundles closely arranged along the Z-axis direction. The XY-axis detection unit (431) and the Z-axis detection unit (432) are located in a closed and shielded space.

9. The corner reflector-based synthetic aperture radar deformation monitoring accuracy verification device according to claim 8, characterized in that: The displacement detection component (42) includes a photosensitive sensor, and the photosensitive sensor is arranged to correspond to each square optical fiber bundle and rectangular optical fiber bundle distribution.

10. A method for verifying deformation monitoring accuracy based on a corner reflector, characterized in that: Using the deformation monitoring accuracy verification device according to any one of claims 1 to 9, comprising the following steps: Step 1: After the corner reflector is arranged, obtain the synthetic aperture radar interferometry measurement result based on the corner reflector. This result is the displacement result of the corner reflector along the radar satellite line of sight, recorded as result A; Step 2: Controlling the corner reflector (50) to move in a predetermined direction through the Z-axis driving component (20) and / or the XY-axis driving component (30), obtaining the actual adjustment displacement of the corner reflector (50) through the displacement feedback component (40), and then calculating the displacement result of the corner reflector in the radar satellite line of sight according to the X-axis or Y-axis azimuth angle and the satellite incident angle; Step 3: Obtain the corner reflector-based synthetic aperture radar interferometry measurement result again, which is recorded as result B; Step 4: Obtain a measured displacement result based on result B and result A, compare the difference between the measured displacement result and the actual displacement true value, and calculate the mean error of the difference as an accuracy evaluation index of the corner reflector interferometry; Wherein, in step 2, the spatial position of a single corner reflector (50) is adjusted during different satellite monitoring periods.

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