Large-span space structure deformation high-precision monitoring method and system based on InSAR technology

Abstract

The invention relates to the technical field of structure health monitoring, in particular to a large-span space structure deformation high-precision monitoring method and system based on the InSAR technology. The reflecting capacity of the structure is improved by installing an angle scatterer CR on the structure. Compensation of flat ground and elevation phase of InSAR measurement is realized by constructing an interference image pair to extract coordinates and elevation coordinates. And then LOS deformation of the angle scatterer CR is decomposed into three-dimensional displacement (longitudinal, transverse and vertical), and verification is carried out by using data of a satellite navigation system. The technology provides a lightweight monitoring method for deformation of a large-span space structure with low scattering efficiency, and the technology is suitable for deformation identification of other low-coherence large-scale urban infrastructures.

Description

Technical Field

[0001] The present invention relates to the technical field of structural health monitoring, and in particular to a high-precision monitoring method and system for deformation of large-span spatial structures based on InSAR technology. Background Art

[0002] Structural health monitoring of large urban infrastructure with long-span spatial structures is of great significance for preventing infrastructure collapse accidents. Structural health monitoring of large-span spatial structures is widely recognized as a key method for obtaining up-to-date information to facilitate early detection of damage and potential threats.

[0003] Interferometry synthetic aperture radar (INSAR) technology, capable of rapidly capturing large-area surface deformations under all-weather and historical conditions, is a promising tool for long-term structural deformation monitoring. The principle of InSAR deformation monitoring is to use differential interferometry processing of two spaceborne SAR images before and after a change to obtain a twisted phase. After phase unwrapping, the absolute phase is obtained to characterize surface elevation change information. However, its application is constrained by the sparse distribution of detectable permanent scatterers (PS), which are mainly affected by the reflective properties of the structure. In addition, errors in satellite-precision orbit data and digital elevation models (DEMs) can affect the estimation of flat ground and elevation phases measured by InSAR, further affecting the accuracy of differential interferometry. Finally, thermal expansion estimates from InSAR technology are based on air temperature data near the structure, and spatial differences between the structure and these sites are ignored.

[0004] Therefore, it is very necessary to provide a new high-precision monitoring method and system for large-span spatial structure deformation based on InSAR technology. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-precision monitoring method and system for large-span spatial structure deformation based on InSAR technology to solve the above-mentioned technical problems.

[0006] The present invention provides a high-precision monitoring method for deformation of a large-span spatial structure based on InSAR technology, comprising the steps of: S1, based on InSAR technology, the SAR image of the covering structure obtained from the structure with the corner reflector CR installed is registered to obtain a registered SAR image; S2, constructing an interferometric image pair based on the time-adjacent SAR images according to the registered SAR images, and extracting and calculating the corner reflectors The residual interference phase With high-precision elevation data ; Indicates corner reflector The residual interference phase in the i-th interference image pair; S3, based on the registered SAR image, reconstructing the interference image pair based on the main image and the auxiliary image, and compensating and calculating the corner reflector Flat Earth Phase and elevation phase ; S4, determining the corner reflector High-precision deformation phase ; S5, performing phase unwrapping processing on the high-precision deformation phase to obtain the corner reflector True deformation phase , and according to the corner reflector True deformation phase Perform deformation inversion to calculate the corner reflector Deformation , ; S6, in the local reference frame (t, l, v) of the structure, for any direction The structure of the corner reflector is constructed Deformation With longitudinal displacement dl, lateral displacement , and vertical displacement Relationship: (A); Among them, t, l and v represent the horizontal, longitudinal and vertical directions respectively; 、 、 is the sensitivity coefficient of the CRI technology to motions in different directions within the local reference frame; is the angle of incidence, α is the azimuth; S7, inverse calculation of the longitudinal displacement , lateral displacement , and vertical displacement .

[0007] Preferably, the step S7 further includes the following steps: , lateral displacement , and vertical displacement Provide early warning for deformation of the large-span spatial structure.

[0008] Preferably, the step S7 includes: Based on the corner reflector set on the transverse movable support 'Only lateral displacement occurs, and the lateral displacement is evenly distributed along the longitudinal axis, and the corner reflector captured by the wireless satellite system 'Lateral displacement The lateral displacement ; Based on the linear relationship between the longitudinal displacement and the distance from the fixed support, the longitudinal displacement dl at different positions is determined by interpolation; The vertical displacement in the LOS direction is derived using the formula (A) in step S6. .

[0009] Preferably, it also includes: S60, establishing the corner reflector Deformation The correspondence with the corresponding three-dimensional displacement in the global coordinate system (E, N, V), ; Among them, E, N, and V represent the east-west direction, north-south direction, and vertical direction respectively; 、 、 They represent displacements in the vertical, north-south, and east-west directions respectively; is the side viewing angle, α is the azimuth angle; Vertical displacement data detected by wireless satellite system , north-south displacement data , displacement data in the east-west direction , through the formula: ; ; ; Verify the corner reflector calculated in step S5 Deformation .

[0010] Preferably, ; ; .

[0011] Preferably, the step S2 includes: Extract and calculate corner reflectors The residual interference phase , , λ is the radar wavelength, represents any unmodeled phase other than the residual elevation phase, represents the elevation error, Represents the corner reflector The vertical baseline, R represents the slope distance, represents the residual elevation phase of the corner reflector in the i-th interferometric image pair; Establishing correlation coefficient Model, and according to the correlation coefficient The value of , determines the optimal estimate of the elevation error, where the correlation coefficient When the maximum value is reached, the corresponding elevation error is the optimal estimate; , where N is the number of SAR interferometric image pairs and j is the imaginary unit; High-precision elevation data h of the corner reflector CR is estimated based on the initial elevation data of the corner reflector and the optimal estimation value of the elevation error.

[0012] Preferably, step S3 includes: Based on the slant range time corresponding to the corner reflector in the main image and the corresponding slant range time in the secondary image , calculate the corner reflector Flat Earth Phase and elevation phase : .

[0013] Preferably, step S3 includes: Calculate the high-precision row and column position data of the corner reflector CR in the main image And high-precision elevation data h, combined with the Doppler equation, slant range equation and ellipsoid equation, calculate the corner reflector Spatial position coordinates under WGS84 ; Based on the calculated corner reflector The spatial position coordinate T, according to the formula: , calculate the azimuth time corresponding to the corner reflector CR in the secondary image ,in, Denotes that and T are Time satellites and corner reflectors The spatial coordinates of for Velocity vector of the satellite at time According to the formula: , calculate the slant range time corresponding to the corner reflector CR in the secondary image ,in, The speed of light.

[0014] Preferably, according to the formula: , calculate the corner reflector True deformation phase ; where n represents an integer.

[0015] The present invention also provides a high-precision monitoring system for deformation of large-span spatial structures based on InSAR technology, comprising a corner reflector CR installed on the structure to be detected, a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology as described in any one of the above items are implemented.

[0016] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the high-precision monitoring method for deformation of a large-span spatial structure based on InSAR technology as described in any of the above items.

[0017] This invention provides a novel, high-precision method and system for monitoring deformation of large-span spatial structures using InSAR (Interferometric Synthetic Aperture Radar) technology using artificial corner reflectors (CRs). By installing CRs on a structure, the structure's reflectivity is enhanced. Coordinates and elevation coordinates are extracted using constructed interferometric image pairs to compensate for the ground and elevation phases measured by InSAR. The CR's Loss of Situation (LOS) deformation is then decomposed into three-dimensional displacements (longitudinal, lateral, and vertical) and verified using data from the Beidou Navigation Satellite System (BDS). This overcomes the problem that InSAR technology can only provide SAR LOS deformation and cannot be directly used for structural performance evaluation according to structural health monitoring specifications.

[0018] The performance of the CR was evaluated by comparing the calculated 3D displacements after decomposing the LOS deformation of the CR with the warning thresholds specified in relevant structural health monitoring standards. The results show that CRI has the potential to advance the use of InSAR technology for long-span spatial structural health monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, as part of this disclosure, are intended to provide a further understanding of the disclosure. The exemplary embodiments of the disclosure and their descriptions are intended to explain the disclosure and do not constitute undue limitations thereon. Obviously, the drawings described below are merely examples, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0020] Figure 1 2 is a flow chart of a method for high-precision monitoring of deformation of large-span spatial structures based on InSAR technology in one embodiment of the present invention.

[0021] Figure 2 The figure is a schematic diagram of an algorithm flow of a method for high-precision monitoring of deformation of large-span spatial structures based on InSAR technology in one embodiment of the present invention.

[0022] Figure 3 This is a three-dimensional deformation decomposition strategy in one embodiment of the present invention.

[0023] Figure 4 1 is a schematic diagram of the hardware structure of a system running a high-precision monitoring method for large-span spatial structure deformation based on InSAR technology in one embodiment of the present invention.

[0024] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical problems solved by the embodiments of the present invention, the technical solutions adopted, and the technical effects achieved, in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other equivalent or obviously modified embodiments obtained by ordinary technicians in this field without paying creative work fall within the scope of protection of the present invention. The embodiments of the present invention can be concretized in a variety of different ways as defined and covered in the claims.

[0026] It should be noted that in the following description, many specific details are given for ease of understanding, but it is obvious that the present invention can be implemented without these specific details.

[0027] It should be noted that, in the absence of clear limitations or conflicts, the various embodiments of the present invention and the technical features therein can be combined with each other to form a technical solution.

[0028] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] In the subsequent description, suffixes such as "module," "component," or "unit" used to represent elements are only used to facilitate the description of the present invention and have no specific meaning. Therefore, "module," "component," or "unit" can be used interchangeably.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings.

[0031] Please combine Figure 1-Figure 3 , Figure 1 In one embodiment of the present invention, a high-precision monitoring method for deformation of a large-span spatial structure based on InSAR technology includes steps S1-S6.

[0032] S1, based on InSAR technology, the SAR image of the covering structure obtained from the structure with the corner reflector CR installed is registered to obtain a registered SAR image; InSAR technology offers advantages such as high cost-effectiveness and high measurement accuracy, making it a viable lightweight measurement method. Assume that there are N+1 SAR images covering a structure, with one designated as the primary image and the remaining images as auxiliary images. These auxiliary images are co-registered and resampled to match the spatial domain of the primary image, forming N interferometric measurement pairs. Specifically, this can include selecting one of the multiple SAR images as a reference SAR image and registering the remaining SAR images to the grid of the reference SAR image through a three-level registration process, including registration based on satellite orbit data, pixel-level registration, and sub-pixel-level registration.

[0033] S2, constructing an interferometric image pair based on the time-adjacent SAR images according to the registered SAR images, and extracting and calculating the corner reflectors The residual interference phase With high-precision elevation data ; Indicates corner reflector The residual interference phase in the i-th interference image pair.

[0034] In the traditional InSAR deformation measurement process, the ground phase and elevation phase can be roughly compensated based on the position information of the corner reflector in the SAR image and the elevation information measured in the field. The residual interference phase of the corner reflector can be expressed as: (1), Among them, the interferometric phase in the SAR image consists of six components: represents the deformation phase; It is the flat earth phase; is the elevation phase; is the atmospheric phase; is the orbit error phase, is the noise phase.

[0035] For CRs mounted on structures, their close spatial arrangement ensures that the use of reference points can effectively eliminate and In addition, the strong reflected signal from the CR leads to a high signal-to-noise ratio (SNR), thus minimizing Therefore, the main contributor to the interference phase is 、 and .Precise compensation and For implementation High-precision measurement is crucial. Air temperature is the main factor affecting the long-term deformation of large-span spatial structures. Therefore, the interferometric measurement model of CRI technology, which introduces thermal expansion parameters into the nonlinear deformation of large-span spatial structures, is expressed as: , Where t is the air temperature at the location of the structure at each SAR image acquisition; λ is the radar wavelength, and k is the thermal expansion coefficient.

[0036] The high-precision position information and phase information of the corner reflector CR in the registered SAR image are accurately extracted by the Sinc interpolation algorithm.

[0037] The elevation phase also introduces errors in the CRI technique. In order to incorporate the elevation phase into the interferometric model, adjacent SAR images in the interferogram generated after registration are used to form an interferometric pair. Based on the simplification of the interferometric phase obtained from temporally adjacent SAR images, the above formula (1) can be simplified to: .

[0038] Preferably, the step S2 includes: Extract and calculate corner reflectors The residual interference phase , , λ is the radar wavelength, represents any unmodeled phase other than the residual elevation phase, represents the elevation error, Represents the corner reflector The vertical baseline, R represents the slope distance, represents the residual elevation phase of the corner reflector in the i-th interferometric image pair; Establishing correlation coefficient Model, and according to the correlation coefficient The value of , determines the optimal estimate of the elevation error, where the correlation coefficient When the maximum value is reached, the corresponding elevation error is the optimal estimate; , where N is the number of SAR interferometric image pairs and j is the imaginary unit; High-precision elevation data h of the corner reflector CR is estimated based on the initial elevation data of the corner reflector and the optimal estimation value of the elevation error.

[0039] in The maximum coefficient corresponds to The optimal search range is determined based on the rough measurement accuracy of the elevation values, improving search efficiency and accuracy. Parameter estimation uses the periodogram method, which applies the discrete Fourier transform algorithm to estimate unknown parameters, offering high computational efficiency and accurate results.

[0040] S3, based on the registered SAR image, reconstructing the interference image pair based on the main image and the auxiliary image, and compensating and calculating the corner reflector Flat Earth Phase and elevation phase .

[0041] Preferably, step S3 includes: Based on the slant range time corresponding to the corner reflector in the main image and the corresponding slant range time in the secondary image , calculate the corner reflector according to formula (3) Flat Earth Phase and elevation phase : (3).

[0042] Preferably, step S3 includes: Calculate the high-precision row and column position data of the corner reflector CR in the main image And high-precision elevation data h, combined with the Doppler equation, slant range equation and ellipsoid equation, calculate the corner reflector Spatial position coordinates under WGS84 ; Based on the calculated corner reflector The spatial position coordinate T, according to the formula: , calculate the azimuth time corresponding to the corner reflector CR in the secondary image ,in, Denotes that and T are Time satellites and corner reflectors The spatial coordinates of for Velocity vector of the satellite at time According to the formula: , calculate the slant range time corresponding to the corner reflector CR in the secondary image ,in, The speed of light.

[0043] The Doppler equation is: ; Slope range equation: ; Ellipsoid equation: ; in, and They are the azimuth time and slant range time corresponding to the position of the corner reflector CR in the main image; express Satellite position vector at time; express Satellite velocity vector at time; The table shows the speed of light; a, b, and c are the parameters of the earth's ellipsoid, and h is the high-precision elevation data h of the corner reflector CR obtained by RTK and other tests.

[0044] In the above formula and The interpolated position of the corner reflector CR can be get: , in, and are the initial sampling time extracted from the SAR image metadata, and The sampling rates are extracted in azimuth and slant range directions respectively.

[0045] S4, determining the corner reflector High-precision deformation phase .

[0046] Specifically, according to formulas (2) and (3), the corner reflector can be calculated as High-precision deformation phase .

[0047] S5, performing phase unwrapping processing on the high-precision deformation phase to obtain the corner reflector True deformation phase , and according to the corner reflector True deformation phase Perform deformation inversion to calculate the corner reflector Deformation , .

[0048] Preferably, according to the formula: , calculate the corner reflector True deformation phase ; where n represents an integer.

[0049] Specifically, in the local reference frame (t, l, v) of the structure, deformation usually occurs simultaneously along all three axes, where t, l, and v represent the lateral, longitudinal, and vertical directions, respectively. The dLOS can be expressed as a linear combination of displacement components in different directions.

[0050] S6, in the local reference frame (t, l, v) of the structure, for any direction The structure of the corner reflector is constructed Deformation With longitudinal displacement dl, lateral displacement , and vertical displacement Relationship: (A); Among them, t, l and v represent the horizontal, longitudinal and vertical directions respectively; 、 、 is the sensitivity coefficient of the CRI technology to motions in different directions within the local reference frame; is the angle of incidence, and α is the azimuth angle.

[0051] Preferably, ; ; .

[0052] Preferably, the method further comprises the steps of: S60, establishing the corner reflector Deformation The correspondence with the corresponding three-dimensional displacement in the global coordinate system (E, N, V), ; Among them, E, N, and V represent the east-west direction, north-south direction, and vertical direction respectively; 、 、 They represent displacements in the vertical, north-south, and east-west directions respectively; is the side viewing angle, α is the azimuth angle; Vertical displacement data detected by the satellite navigation system , north-south displacement data , displacement data in the east-west direction , through the formula: ; ; ; Verify the corner reflector calculated in step S5 Deformation .

[0053] Specifically, InSAR technology can only provide SAR LOS deformation and cannot be directly used for structural performance evaluation according to structural health monitoring specifications.

[0054] The influence of different load types causes significant changes in the direction of structural movement.

[0055] For example, longitudinal deformation is mainly affected by air temperature, while lateral displacement is mainly driven by wind load. Assuming that the actual displacement occurs entirely along one of the three main directions (longitudinal, lateral or vertical) and no other motion contributes to the measured dLOS, the corresponding estimated displacement in the global coordinate system (E, N, V) is expressed as follows: ; ; ; Compared to estimates in a global reference frame, estimates obtained in a structure's local system take into account the structure's orientation. Notably, the sensitivity of InSAR measurements to longitudinal and lateral displacements depends on the geometric parameters θ, α, and β. In contrast, sensitivity to vertical displacements depends solely on the angle of incidence θ.

[0056] In step S7, a structure-driven deformation decomposition strategy is proposed to invert the structural 3D displacement from the LOS deformation, taking into account the influence of the structural supports on the CR motion. Before applying this displacement inversion strategy, two assumptions from previous studies need to be clarified. First, due to the high stiffness of long-span spatial structures, the lateral displacement is assumed to be uniformly distributed along the longitudinal axis. Second, the longitudinal displacement at different locations is assumed to be linearly related to the distance from the fixed supports.

[0057] S7, inverse calculation of the longitudinal displacement , lateral displacement , and vertical displacement .

[0058] Preferably, the step S7 includes: Based on the corner reflector set on the transverse movable support 'Only lateral displacement occurs, and the lateral displacement is evenly distributed along the longitudinal axis, and the corner reflector captured by the wireless satellite system 'Lateral displacement The lateral displacement ; Based on the linear relationship between the longitudinal displacement and the distance from the fixed support, the longitudinal displacement dl at different positions is determined by interpolation; The vertical displacement in the LOS direction is derived using the formula (A) in step S6. .

[0059] Preferably, the step S7 further includes the following steps: , lateral displacement , and vertical displacement Early warning is provided for the deformation of the large-span spatial structure. For example, when the displacement in a certain direction reaches a preset danger threshold, an alarm may be issued.

[0060] This invention provides a novel, high-precision method and system for monitoring deformation of large-span spatial structures using InSAR (Interferometric Synthetic Aperture Radar) technology using artificial corner reflectors (CRs). By installing CRs on a structure, the structure's reflectivity is enhanced. Coordinates and elevation coordinates are extracted using constructed interferometric image pairs to compensate for the ground and elevation phases measured by InSAR. The CR's Loss of Situation (LOS) deformation is then decomposed into three-dimensional displacements (longitudinal, lateral, and vertical) and verified using data from the Beidou Navigation Satellite System (BDS). This overcomes the problem that InSAR technology can only provide SAR LOS deformation and cannot be directly used for structural performance evaluation according to structural health monitoring specifications.

[0061] The performance of the CR was evaluated by comparing the calculated 3D displacements after decomposing the LOS deformation of the CR with the warning thresholds specified in relevant structural health monitoring standards. The results show that CRI has the potential to advance the use of InSAR technology for long-span spatial structural health monitoring.

[0062] Please combine Figure 4 The present invention also provides a high-precision monitoring system for deformation of large-span spatial structures based on InSAR technology. The high-precision monitoring system for deformation of large-span spatial structures based on InSAR technology is established and operated on the basis of a computer system, and specifically includes a memory 61, a processor 62, and a computer program 63 stored in the memory 61 and executable on the processor 62. When the processor 62 executes the computer program 63, the steps of the high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology as described in any one of the above items are implemented.

[0063] This embodiment also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology as described in any of the above items.

[0064] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0065] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0066] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0067] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0068] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0069] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0070] If the integrated module / unit is implemented as a software functional unit and sold or used as a standalone product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention can implement all or part of the process steps in the above-mentioned method embodiments by using a computer program to instruct the relevant hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of each of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal, and software distribution medium. It should be noted that the content of the computer-readable medium can be appropriately increased or decreased based on the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, based on legislation and patent practice, computer-readable media does not include electric carrier signals and telecommunication signals.

[0071] The present invention is therefore intended to be illustrative and non-restrictive in all respects, with the scope of the invention being defined by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalents of the application documents are intended to be embraced therein.

[0072] Throughout this specification, references to "one embodiment," "another embodiment," "other embodiments," or "first through Xth embodiments" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, method steps, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0073] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0074] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology, characterized in that: Including steps: S1, based on InSAR technology, the SAR image of the covering structure obtained from the structure with the corner reflector CR installed is registered to obtain a registered SAR image; S2, constructing an interferometric image pair based on the time-adjacent SAR images according to the registered SAR images, and extracting and calculating the corner reflectors The residual interference phase With high-precision elevation data ; Indicates corner reflector The residual interference phase in the i-th interference image pair; S3, based on the registered SAR image, reconstructing the interference image pair based on the main image and the auxiliary image, and compensating and calculating the corner reflector Flat Earth Phase and elevation phase ; S4, determining the corner reflector High-precision deformation phase ; S5, performing phase unwrapping processing on the high-precision deformation phase to obtain the corner reflector True deformation phase , and according to the corner reflector True deformation phase Perform deformation inversion to calculate the corner reflector Deformation , ; S6, in the local reference frame (t, l, v) of the structure, for any direction The structure of the corner reflector is constructed Deformation With longitudinal displacement dl, lateral displacement , and vertical displacement Relationship: （A）； Among them, t, l and v represent the horizontal, longitudinal and vertical directions respectively; 、 、 is the sensitivity coefficient of the CRI technology to motions in different directions within the local reference frame; is the angle of incidence, α is the azimuth; S7, inverse calculation of the longitudinal displacement , lateral displacement , and vertical displacement .

2. The high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology according to claim 1 is characterized in that: After step S7, the step of: , lateral displacement , and vertical displacement Provide early warning for deformation of the large-span spatial structure.

3. The high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology according to claim 1 is characterized in that: The step S7 includes: Based on the corner reflector set on the transverse movable support 'Only lateral displacement occurs, and the lateral displacement is evenly distributed along the longitudinal axis, and the corner reflector captured by the wireless satellite system 'The lateral displacement is obtained by ; Based on the linear relationship between the longitudinal displacement and the distance from the fixed support, the longitudinal displacement dl at different positions is determined by interpolation; The vertical displacement in the LOS direction is derived using the formula (A) in step S6. .

4. The high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology according to claim 1 is characterized in that: Also includes: S60, establishing the corner reflector Deformation The correspondence with the corresponding three-dimensional displacement in the global coordinate system (E, N, V), ； Among them, E, N, and V represent the east-west direction, north-south direction, and vertical direction respectively; 、 、 They represent displacements in the vertical, north-south, and east-west directions respectively; is the side viewing angle, α is the azimuth angle; Vertical displacement data detected by wireless satellite system , north-south displacement data , displacement data in the east-west direction , through the formula: ； ； ； Verify the corner reflector calculated in step S5 Deformation .

5. The high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology according to claim 1 is characterized in that: ； ； 。 6. The high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology according to claim 1 is characterized in that: The step S2 comprises: Extract and calculate corner reflectors The residual interference phase , , λ is the radar wavelength, represents any unmodeled phase other than the residual elevation phase, represents the elevation error, Represents the corner reflector The vertical baseline, R represents the slope distance, represents the residual elevation phase of the corner reflector in the i-th interferometric image pair; Establishing correlation coefficient Model, and according to the correlation coefficient The value of , determines the optimal estimate of the elevation error, where the correlation coefficient When the maximum value is reached, the corresponding elevation error is the optimal estimate; , where N is the number of SAR interferometric image pairs and j is the imaginary unit; High-precision elevation data h of the corner reflector CR is estimated based on the initial elevation data of the corner reflector and the optimal estimation value of the elevation error.

7. The high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology according to claim 1 is characterized in that: The step S3 comprises: Based on the slant range time corresponding to the corner reflector in the main image and the corresponding slant range time in the secondary image , calculate the corner reflector Flat Earth Phase and elevation phase : .

8. The high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology according to claim 7 is characterized in that: The step S3 comprises: Calculate the high-precision row and column position data of the corner reflector CR in the main image And high-precision elevation data h, combined with the Doppler equation, slant range equation and ellipsoid equation, calculate the corner reflector Spatial position coordinates under WGS84 ; Based on the calculated corner reflector The spatial position coordinate T, according to the formula: , calculate the azimuth time corresponding to the corner reflector CR in the secondary image ,in, Denotes that and T are Time satellites and corner reflectors The spatial coordinates of for Velocity vector of the satellite at time According to the formula: , calculate the slant range time corresponding to the corner reflector CR in the secondary image ,in, The speed of light.

9. The high-precision monitoring method for deformation of large-span spatial structures based on InSAR technology according to claim 1 is characterized in that: According to the formula: , calculate the corner reflector True deformation phase ; where n represents an integer.

10. A high-precision monitoring system for large-span spatial structure deformation based on InSAR technology, characterized by: The invention comprises a corner reflector CR installed on a structure to be detected, a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the high-precision monitoring method for deformation of a large-span spatial structure based on InSAR technology as described in any one of claims 1 to 9 are implemented.

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