Ground-based GNSS-R surface deformation monitoring method and system for slope scenarios

Abstract

This invention provides a ground-based GNSS-R method and system for monitoring surface deformation in slope scenarios, belonging to the field of GNSS satellite navigation and remote sensing technology. The method includes: establishing a two-dimensional Cartesian coordinate system with the ground point of the observation station as the origin, calibrating environmental parameters, and determining the phase center point of the direct antenna and the phase center point of the reflective antenna; establishing the reflective surface equation of the slope based on the environmental parameters, and determining the mirror point of the phase center point of the reflective antenna; establishing an error compensation model based on the phase center point of the direct antenna, the phase center point of the reflective antenna, and the mirror point, and determining the distance deviation and angle deviation; performing error compensation based on the distance deviation and the angle deviation, and inverting to obtain the surface deformation monitoring results. This invention proposes an error compensation strategy for surface deformation monitoring in slope scenarios, which can effectively improve the solution accuracy and applicability of the differential GNSS-R method in slope surface deformation monitoring.

Description

Technical Field

[0001] This invention belongs to the field of GNSS satellite navigation and remote sensing technology, and in particular relates to a ground-based GNSS-R surface deformation monitoring method and system for slope scenarios. Background Technology

[0002] Global Navigation Satellite System–Reflectometry (GNSS-R) is a remote sensing technology that uses GNSS satellite reflected signals to monitor physical parameters of the Earth's surface. It relies on different receiving platforms (ground-based, space-based, and satellite-based) to receive GNSS reflected signals and extracts surface information using electromagnetic wave scattering theory. Currently, GNSS-R has achieved significant results in large-scale monitoring fields such as land and ocean remote sensing, enabling high-precision inversion of physical quantities such as surface deformation, surface height, snow thickness, river water level, and soil moisture.

[0003] Traditional methods for monitoring surface deformation, such as leveling, precise point positioning, synthetic aperture radar (SAR), and 3D laser scanning, while offering high measurement accuracy, struggle to simultaneously achieve advantages like high spatiotemporal resolution, strong resistance to environmental and weather interference, and low cost. In contrast, GNSS-R technology boasts outstanding features such as all-weather, all-day observation, abundant free signal sources, wide signal coverage, high spatiotemporal resolution, and low cost. It demonstrates broad application prospects in surface deformation monitoring, particularly in engineering safety fields such as slope stability monitoring, landslide early warning, roadbed settlement monitoring, and dam deformation monitoring.

[0004] However, existing dual-antenna GNSS-R ground height change monitoring methods typically employ reflection models based on the assumption of a flat ground surface to construct signal propagation geometry. Both the geometric relationship and path difference calculations use a horizontal plane as the reflecting surface. In real-world monitoring scenarios, the monitoring surface is generally a slope with a certain angle, causing significant distortion in the signal propagation path. Traditional models struggle to adapt to complex terrain environments, leading to systematic angular and distance errors in the signal propagation path. This results in errors in ground height inversion, increased deviations in epoch-time deformation calculations, and drift in monitoring results, ultimately significantly reducing monitoring accuracy and failing to meet high-precision engineering requirements.

[0005] Therefore, there is an urgent need for a method to monitor surface deformation that can accurately quantify the systematic errors of angles and distances in slope scenarios, in order to adapt to complex terrain environments. Summary of the Invention

[0006] This invention provides a ground-based GNSS-R surface deformation monitoring method and system for slope scenarios, which solves the shortcomings of existing GNSS-R surface deformation monitoring methods that cannot adapt to slope scenarios, and realizes high-precision surface deformation monitoring in complex terrain environments.

[0007] In a first aspect, the present invention provides a ground-based GNSS-R surface deformation monitoring method for slope scenarios, comprising: A two-dimensional Cartesian coordinate system is established with the ground point of the observation station as the origin, and environmental parameters are calibrated to determine the phase center point of the direct antenna and the phase center point of the reflected antenna. Based on the environmental parameters, establish the reflection surface equation of the slope in the two-dimensional Cartesian coordinate system, and determine the mirror point of the phase center point of the reflecting antenna based on the reflection surface equation; Based on the phase center point of the direct antenna, the phase center point of the reflected antenna, and the mirror point Establish an error compensation model to determine the distance deviation and angle deviation. Error compensation is performed on the distance and angle of the surface deformation monitoring based on the distance deviation and angle deviation to obtain the surface deformation monitoring results.

[0008] This invention provides a ground-based GNSS-R surface deformation monitoring method for slope scenarios. The environmental parameters include at least the structural parameters of the antenna mounting base, the slope, the coordinates of the intersection of the slope and the ground, and the location of the observation station.

[0009] This invention provides a ground-based GNSS-R surface deformation monitoring method for slope scenarios. The step of establishing the reflection surface equation of the slope in the two-dimensional Cartesian coordinate system based on the environmental parameters, and determining the mirror point of the phase center point of the reflecting antenna based on the reflection surface equation, includes: The slope is simplified to a smooth inclined plane with a fixed slope. Based on the slope and the coordinates of the intersection point between the slope and the ground, the equation of the straight line of the slope in the two-dimensional Cartesian coordinate system is determined as the equation of the reflecting surface. Based on the equation of the straight line, the mirror point of the phase center point of the reflective antenna is determined by the symmetry relationship.

[0010] This invention provides a ground-based GNSS-R surface deformation monitoring method for slope scenarios. The step of establishing an error compensation model based on the phase center point of the direct antenna, the phase center point of the reflected antenna, and the image point to determine the distance deviation and angle deviation includes: Determine a first distance between the phase center point of the direct antenna and the mirror point, and a second distance between the phase center point of the reflective antenna and the mirror point; determine the distance deviation based on the difference between the first distance and the second distance. Determine the first angle between the equation of the line containing the phase center point of the direct antenna and the mirror point and the horizontal axis of the two-dimensional Cartesian coordinate system, and the second angle between the equation of the line containing the phase center point of the reflective antenna and the mirror point and the horizontal axis. Determine the angle deviation based on the difference between the first angle and the second angle.

[0011] This invention provides a ground-based GNSS-R surface deformation monitoring method for slope scenarios. The process of establishing the reflection surface equation of the slope in the two-dimensional Cartesian coordinate system and determining the mirror point of the phase center point of the reflecting antenna based on the reflection surface equation includes: The slope is subjected to gridded discrete sampling to obtain a set of discrete sampling points, which includes the local slope elevation value and local slope inclination at each grid point. Based on the set of discrete sampling points, the continuous surface equation of the slope is fitted using the bilinear interpolation method as the equation of the reflecting surface; Based on the environmental parameters, a local specular reflection point that satisfies the law of reflection is searched on the equation of the continuous surface. A tangent plane is determined in the neighborhood of the local specular reflection point. The mirror point of the phase center point of the reflecting antenna is determined based on the tangent plane.

[0012] This invention provides a ground-based GNSS-R surface deformation monitoring method for slope scenarios. Before performing error compensation on the distance and angle of the surface deformation monitoring based on the distance deviation and the angle deviation to obtain the surface deformation monitoring results, the method further includes: Real-time acquisition of meteorological sensor data and GNSS satellite elevation angle at the monitoring site; construction of a signal atmospheric refraction propagation time delay sub-model. The additional path distance error caused by meteorological disturbances is quantified based on the atmospheric refraction and propagation delay sub-model of the signal. The additional path distance error is linearly coupled to the distance deviation. In the process, update the distance deviation.

[0013] This invention provides a ground-based GNSS-R surface deformation monitoring method for slope scenarios. The method further includes: The Kalman time-series filtering algorithm is used to smooth and denoise the distance and angle deviations obtained from continuous observation epochs, and an adaptive iterative update threshold is set to dynamically update the correlation coefficient of the error compensation model epoch by epoch.

[0014] Secondly, the present invention also provides a ground-based GNSS-R surface deformation monitoring system for slope scenarios, comprising: The parameter calibration module is used to establish a two-dimensional Cartesian coordinate system with the ground point of the observation station as the origin, and to calibrate environmental parameters to determine the phase center point of the direct antenna and the phase center point of the reflected antenna. The geometric modeling module is used to establish the reflection surface equation of the slope in the two-dimensional Cartesian coordinate system based on the environmental parameters, and to determine the mirror point of the phase center point of the reflecting antenna based on the reflection surface equation. The error calculation module is used to establish an error compensation model based on the phase center point of the direct antenna, the phase center point of the reflected antenna, and the mirror point, and to determine the distance deviation and angle deviation. The deformation inversion module is used to compensate for errors in the distance and angle of the surface deformation monitoring based on the distance deviation and the angle deviation, and to invert the surface deformation monitoring results.

[0015] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the ground-based GNSS-R surface deformation monitoring method for slope-oriented scenarios as described above.

[0016] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the ground-based GNSS-R surface deformation monitoring method for slope-oriented scenarios as described above.

[0017] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the ground-based GNSS-R surface deformation monitoring method for slope-oriented scenarios as described above.

[0018] The beneficial effects of the technical solutions provided by some embodiments of the present invention include at least the following: 1) This invention provides a ground-based GNSS-R surface deformation monitoring method and system for slope scenarios. By establishing a mirror image of the phase center point of the reflecting antenna as defined in the two-dimensional Cartesian coordinate system, an error compensation model is constructed. This model quantifies angular and distance deviations, enabling precise correction of these deviations and offsetting these two types of errors in surface deformation monitoring, thereby improving the performance of differential GNSS. The accuracy and applicability of R in slope deformation monitoring.

[0019] 2) The present invention can simplify the slope into a smooth inclined plane with a fixed slope. Based on the slope and the coordinates of the intersection of the slope and the ground, the straight line equation of the slope in the two-dimensional plane rectangular coordinate system is determined as the equation of the reflecting surface. Thus, the mirror point of the phase center point of the reflecting antenna can be quickly determined through the symmetry relationship. While adapting to the change from horizontal plane scene to slope scene, the calculation efficiency of error compensation is improved.

[0020] 3) The present invention can also perform gridded discrete sampling on the slope surface, fit the continuous surface equation of the slope surface as the reflection surface equation, so that the reflection geometry model can accurately fit the undulating shape of the actual ground surface, realize distance error correction based on slope micro-topography fitting, effectively suppress the residual modeling error caused by the single slope assumption of micro-topography undulation, and improve the monitoring accuracy and stability in complex slope scenarios.

[0021] 4) This invention quantifies and compensates for the additional path error introduced by meteorological disturbances by constructing a signal atmospheric refraction propagation time delay sub-model, thereby achieving dual-layer joint compensation of static geometric error and dynamic environmental time-varying error, reducing residual error and monitoring drift caused by meteorological disturbances, and further improving the accuracy of surface deformation monitoring.

[0022] 5) This invention dynamically updates the coefficients of the error compensation model epoch by epoch, adaptively adjusting relevant parameters to adapt to changes in the monitoring environment, effectively suppressing monitoring drift caused by random noise in observation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a flowchart illustrating the ground-based GNSS-R surface deformation monitoring method for slope scenarios provided by the present invention. Figure 2 This is a front view of the antenna mounting base used in this invention; Figure 3 This is a schematic diagram of the dual-antenna GNSS signal propagation path in a slope-facing scenario provided by the present invention; Figure 4 This is a schematic diagram of the simulation results of the error compensation model provided by the present invention in a certain experiment; Figure 5This is a schematic diagram of the structure of the ground-based GNSS-R surface deformation monitoring system for slope scenarios provided by the present invention; Figure 6 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] Currently, existing technologies lack dedicated error compensation modeling for slope scenarios. The superposition of distance and angle errors in slope scenarios leads to a decrease in the accuracy of deformation inversion, making it difficult to meet the high-precision monitoring requirements of sloping surfaces such as slopes and landslides. Furthermore, existing slope error compensation models often use a single, overall slope inclination angle for idealized modeling, ignoring the micro-topographical undulations present on actual slopes. A single slope parameter cannot accurately represent the true geometric shape of local reflective surfaces, easily introducing residual modeling errors.

[0027] Furthermore, during long-term field monitoring, changes in atmospheric temperature and humidity can cause delays in the propagation and refraction of GNSS signals. The antenna is subjected to wind and temperature stress, which can cause slight displacement and deformation of the base. In addition, the real-time changes in satellite elevation angle and random noise interference from epoch observations mean that static error compensation models based on fixed parameters can only be adapted to ideal static slope scenarios, and are difficult to meet the long-term millimeter-level high-precision time-series monitoring requirements for landslides, slopes, and other engineering projects.

[0028] Therefore, considering the diversity of actual monitoring scenarios, when the monitoring scenario switches from flat ground to complex terrain such as slopes, there are slight angular and distance errors between the constructed reflection model and the actual signal propagation path due to the influence of the monitoring environment and the structural design characteristics of the antenna mounting base of the ground-based GNSS-R observation platform. Currently, there is no integrated dynamic error compensation scheme for slope micro-topography, atmospheric refraction, antenna base deformation, and time-series observation noise.

[0029] This invention addresses the unique systematic angular deviations and distance errors in such scenarios by proposing a targeted error compensation model. By calibrating parameters such as the structural parameters of the antenna mounting base, the slope inclination angle, and the location of the observation station, the two types of deviations are accurately modeled, the systematic deviation values ​​are obtained and corrected, thereby effectively improving the solution accuracy and applicability of the differential GNSS-R method in slope surface deformation monitoring.

[0030] Please see Figure 1 , Figure 1 One of the flowcharts for a ground-based GNSS-R surface deformation monitoring method for slope scenarios provided as an embodiment of the present invention includes: S101. Establish a two-dimensional Cartesian coordinate system with the ground point of the observation station as the origin, calibrate the environmental parameters, and determine the phase center point of the direct antenna and the phase center point of the reflected antenna. S102. Based on environmental parameters, establish the equation of the reflecting surface of the slope in a two-dimensional plane rectangular coordinate system, and determine the mirror point of the phase center point of the reflecting antenna based on the equation of the reflecting surface. S103. Based on the phase center point of the direct antenna, the phase center point of the reflected antenna, and the mirror point, establish an error compensation model to determine the distance deviation and angle deviation. S104. Based on the distance deviation and angle deviation, error compensation is performed on the distance and angle of the surface deformation monitoring to obtain the surface deformation monitoring results.

[0031] This invention establishes the mirror image of the phase center point of the reflecting antenna in a two-dimensional Cartesian coordinate system, representing the reflection surface equation of the slope. Based on this, an error compensation model is constructed, quantifying angular and distance deviations to achieve precise correction. This offsets these two types of errors in surface deformation monitoring, improving the performance of differential GNSS. The accuracy and applicability of R in slope deformation monitoring.

[0032] Traditional dual-antenna mounting methods typically mount the direct antenna vertically upwards and the reflector antenna vertically downwards. This invention employs an antenna mounting base that allows for flexible adjustment of the reflector antenna's tilt angle, such as... Figure 2 The image shows a front view of the antenna mounting base used in this invention. It includes a ring base, a rotation axis for the direct-fire antenna, and a rotation axis for the reflective antenna. One end of each of these rotation axes is fixed to the center of the ring base, and the other end of the direct-fire antenna's rotation axis is vertically fixed upwards to the ring base using a nut. The direct-fire antenna is connected via its rotation axis, and the reflective antenna is connected via its rotation axis. The ring base has 11 angle adjustment holes, with an included angle of 15° between adjacent holes. The rotation axis of the reflective antenna can be rotated around the center of the ring base to adjust to different angle adjustment holes and is fixed to the ring base using a nut. Each angle adjustment hole corresponds to a different tilt angle of the reflective antenna.

[0033] In practical applications, the antenna mounting base is erected on the ground using a bracket. By adjusting the tilt angle of the reflecting antenna on the mounting base, the angle between the reflecting antenna and the vertical direction can be increased, thereby expanding the monitoring range and ensuring that the reflecting antenna fully receives GNSS reflected signals from the reflecting area. This allows for flexible adaptation to more monitoring environments. This invention employs... Figure 2The antenna mounting base is used for data acquisition in slope scenarios.

[0034] In the above implementation, for step S101, a two-dimensional Cartesian coordinate system is first established for the slope scene.

[0035] Using the ground point of the observation station as the origin O(0,0), and the direction parallel to the flat ground as the positive x-axis and the vertical upward direction of the observation station as the positive y-axis, a two-dimensional Cartesian coordinate system xOy is established. Based on this two-dimensional Cartesian coordinate system, environmental parameters are calibrated, and the phase center points of the direct antenna and the reflective antenna are determined for subsequent quantization calculations.

[0036] In some possible embodiments, the environmental parameters include the structural parameters of the antenna mounting base, the slope, the coordinates of the intersection of the slope and the ground, and the location of the observation station. The structural parameters of the antenna mounting base may include the lengths of the two rotation axes connecting the direct antenna and the reflective antenna, the tilt angle of the reflective antenna during measurement, the projected lengths of the phase centers of the direct and reflective antennas in the vertical direction, the distance between the mirror images of the phase centers of the direct and reflective antennas in the north direction, and the projected lengths of the phase centers of the direct and reflective antennas in the horizontal direction.

[0037] In a slope scenario, the signal propagation path of a dual-antenna GNSS is as follows: Figure 3 As shown, Figure 3 The image clearly illustrates the spatial positions and geometric relationships of the direct-fire antenna and the reflective antenna in a sloped scene. The center point of the antenna mounting base is A, and the phase center of the direct-fire antenna is point C, with coordinates [coordinates missing]. The phase center of the reflected antenna is located at point B, with coordinates as follows: Point F is the perpendicular point of the phase center point B of the reflecting antenna on the slope; G is the intersection of the slope and the ground; and D is the specular reflection point of the GNSS direct signal on the slope. Figure 3 In this context, assuming the slope is a mirror-reflecting surface with a fixed gradient, the mirror image position of the phase center point B of the reflecting antenna can be obtained based on symmetry. E is the distance from the phase center point C of the direct-fire antenna. The perpendicular point.

[0038] Depend on Figure 3 It can be seen that, The relationships form a right triangle, with all variables' relationships revolving around this triangle. The construction involves a triangle where the phase center point B of the reflecting antenna is not on the side of the relationship triangle. The height h of the reflecting antenna's phase center from the ground surface is represented by line segment BF. Therefore, the ground surface height h cannot be directly correlated with the relationship triangle; a straight line must be established instead. and The relationship between these factors is used to calculate the surface height h and the changes in surface elevation between epochs. Based solely on the slope gradient and satellite elevation angle, only ∠ can be obtained. It is impossible to obtain the ∠ in the right triangle. There exists an angular deviation ∠ .

[0039] Therefore, there are angular deviations and height-distance deviations. These two types of deviations directly lead to errors in the calculation of surface height between epochs, affecting the accuracy of surface deformation calculations. Therefore, it is necessary to quantitatively analyze the magnitude of these two types of deviations and construct an error compensation model to compensate for and correct the deviations, thereby achieving high-precision calculations of surface height and deformation.

[0040] In the above implementation, for step S102, the equation of the reflecting surface of the slope in the two-dimensional plane rectangular coordinate system xOy is established, and the mirror point of the phase center point of the reflecting antenna relative to the reflecting surface is determined.

[0041] To simplify the calculation, the slope can be simplified to a smooth inclined plane with a fixed slope. By utilizing the mirror reflection relationship, the mirror image point of the phase center point of the reflecting antenna relative to the reflecting surface can be quickly determined.

[0042] In some possible embodiments, the equation of the reflecting surface of the slope in a two-dimensional Cartesian coordinate system is established, and the mirror point of the phase center point of the reflecting antenna is determined according to the equation of the reflecting surface, including: The slope is simplified to a smooth inclined plane with a fixed slope. Based on the slope and the coordinates of the intersection point between the slope and the ground, the equation of the straight line of the slope in a two-dimensional plane rectangular coordinate system is determined as the equation of the reflecting surface. Based on the equation of a straight line, the mirror image point of the phase center point of the reflecting antenna is determined through symmetry.

[0043] Specifically, Figure 3 As shown, when the slope is simplified to a smooth inclined plane with a fixed slope, the equation of the reflecting surface in the two-dimensional Cartesian coordinate system is the equation of the straight line on which the slope lies.

[0044] Let the slope of the slope be... At a fixed slope Next, establish the equation of the slope as a straight line in the rectangular coordinate system xOy:

[0045] in, Let G be the x-coordinate of the intersection point G of the slope and the flat ground.

[0046] The point symmetric to the phase center point B of the reflecting antenna with respect to the equation of the straight line on the slope is its mirror image. Its coordinates are:

[0047] The above describes an idealized model based on the slope angle of a single, integral slope, using the straight-line equation of the slope as the equation of the reflecting surface to obtain the mirror point. coordinates ( .

[0048] This invention simplifies the slope into a smooth inclined plane with a fixed slope. Based on the slope and the coordinates of the intersection of the slope and the ground, the straight line equation of the slope in a two-dimensional Cartesian coordinate system is determined as the equation of the reflecting surface. Thus, the mirror point of the phase center point of the reflecting antenna is quickly determined through symmetry. This improves the calculation efficiency of error compensation while adapting to the change from horizontal to slope scenes.

[0049] In real-world slope scenarios, the micro-topographical undulations of slopes mean that a single slope parameter cannot accurately represent the true geometry of the local reflective surface. Therefore, a continuous surface equation can be constructed using a high-resolution DEM to replace the linear equation based on a single slope angle. This continuous surface equation can then be used as the actual reflective surface equation for more accurate error compensation, thereby reducing geometric calculation errors caused by topographical undulations.

[0050] In some possible embodiments, the equation of the reflecting surface of the slope in a two-dimensional Cartesian coordinate system is established, and the mirror point of the phase center point of the reflecting antenna is determined according to the equation of the reflecting surface, including: The slope is subjected to gridded discrete sampling to obtain a set of discrete sampling points, which includes the local slope elevation value and local slope inclination at each grid point. Based on the set of discrete sampling points, the continuous surface equation of the slope is fitted using the bilinear interpolation method as the equation of the reflecting surface; Search for local specular reflection points that satisfy the law of reflection on the continuous surface equation, determine a tangent plane in the neighborhood of the local specular reflection point, and determine the mirror point of the phase center point of the reflecting antenna based on the tangent plane.

[0051] Specifically, the monitoring area where the slope is located is sampled in a grid, with the grid spacing controlled between 0.5 m and 2 m. In areas with complex terrain (such as places with drastic local changes in elevation), adaptive densification sampling is performed, and the local slope elevation and local slope inclination at each grid point form a set of discrete sampling points.

[0052] Based on discrete sampling points, the continuous surface equation of the entire slope is constructed using a bilinear interpolation method:

[0053] in, For any point on the slope The fitted elevation values; i,j) represents the grid sampling point index; u and v are normalized grid coordinate coefficients, ranging from 0 to 1, representing the relative position of the target point within the grid cell; For grid sampling points ( i,j The measured local slope elevation value. For grid sampling points ( i +1, j The measured local slope elevation values. For grid sampling points ( i , j +1) Measured local slope elevation values. For grid sampling points ( i +1, j +1) Measured local slope elevation.

[0054] The bilinear interpolation method ensures that the fitted surface is continuous at the grid boundaries and passes through all measured grids by performing linear interpolation in both the x and y directions, thus achieving a point-by-point continuous description of micro-topographic undulations.

[0055] Then, based on Fermat's principle (minimum time path) and environmental parameters, on the surface... The coordinates of the true reflection point satisfying the angle of incidence equals the angle of reflection are used as the local specular reflection point P. For example, the true reflection point satisfying the angle of incidence = angle of reflection can be searched using iterative methods (such as Newton's method, gradient descent, etc.).

[0056] In theory, based on this local specular reflection point, the actual propagation path difference between the direct signal and the reflected signal can be calculated to correct the distance error, but this method increases computational complexity.

[0057] Therefore, in this embodiment, within the local neighborhood of the local mirror reflection point P, the curved surface is approximated as a tangent plane, thereby utilizing the geometric convenience of the mirror method, based on the mirror point... The mirror image of the phase center point B of the reflecting antenna is determined by its symmetry with respect to the tangent plane. This improves computational efficiency while ensuring computational accuracy.

[0058] Understandably, curved surfaces In the two-dimensional Cartesian coordinate system established in this invention, it appears as only a curve. Therefore, we can first search for a local specular reflection point P that satisfies the law of reflection on this curve. That is, we find a point P on this curve such that the normal PP' of the tangent plane at point P satisfies the following: the angle between the direct signal and PP' is equal to the angle between the reflected signal and PP'.

[0059] This invention can perform gridded discrete sampling of the slope surface and fit the continuous surface equation of the slope surface as the reflection surface equation, so that the reflection geometry model can accurately fit the undulating shape of the actual ground surface. This enables distance error correction based on slope micro-topography fitting, effectively suppresses the residual modeling error caused by making a single slope assumption on micro-topography undulations, and improves the monitoring accuracy and stability in complex slope scenarios.

[0060] It is understood that this invention provides a variety of different methods for determining mirror points to meet different computational efficiency and accuracy requirements, and can be selected according to actual needs.

[0061] In the above implementation, for step S103, an error compensation model is established based on the distance relationship between the phase center point of the direct antenna, the phase center point of the reflected antenna and the image point, and the angular relationship between the linear equations, thereby determining the distance deviation and the angular deviation.

[0062] In some possible embodiments, an error compensation model is established based on the phase center point of the direct antenna, the phase center point of the reflected antenna, and the mirror point to determine the distance deviation and angle deviation, including: Determine the first distance between the phase center point of the direct antenna and the mirror point, and the second distance between the phase center point of the reflected antenna and the mirror point. Determine the distance deviation based on the difference between the first distance and the second distance. Determine the first angle between the equation of the line containing the phase center point and the mirror point of the direct antenna and the horizontal axis of the two-dimensional Cartesian coordinate system, and the second angle between the equation of the line containing the phase center point and the mirror point of the reflective antenna and the horizontal axis. Determine the angular deviation based on the difference between the first and second angles.

[0063] Specifically, taking the straight line equation of the slope as the reflection surface equation as an example, the error compensation model includes two parts: distance deviation quantification modeling and angle deviation quantification modeling.

[0064] (1) Distance deviation quantification modeling Based on the phase center point C of the direct antenna The phase center point B of the reflected antenna Mirror point of the phase center of the reflective antenna The first distance between the phase center point of the direct antenna and the mirror point, and the second distance between the phase center point of the reflected antenna and the mirror point are calculated respectively, as follows:

[0065]

[0066] in, The first distance between the phase center point and the mirror point of the direct antenna. This is the second distance between the phase center point of the reflecting antenna and the mirror point.

[0067] From this, the distance deviation can be derived. :

[0068] (2) Quantitative modeling of angle deviation First, find the line segment. and line segments The slope of the straight line equation is as follows:

[0069]

[0070] The angle between the equations of the two lines and the x-axis can be found using the arctangent function, as follows:

[0071]

[0072] From this, the angular deviation can be derived. :

[0073] Based on the above error compensation model, and combined with some actual parameters in the on-site environmental calibration model, the specific values ​​of distance deviation and angle deviation under the current observation environment can be calculated.

[0074] In the above implementation, for step S104, distance deviation and angle deviation are added during the deformation monitoring and calculation process, while the other parameters remain unchanged, so that deformation inversion can be completed in the slope scenario.

[0075] Because this invention uses a flexible adjustable antenna mounting base for the reflective antenna, the geometric model of the GNSS-R signal propagation path in a horizontal ground scenario is as follows:

[0076] in, , represents the path lengths of the reflected signal and the direct signal, respectively; h represents the vertical height of the phase center of the reflecting antenna from the reflecting surface (ground surface); L 1 and L 2 represents the length of the rotation axis connecting the direct antenna and the reflective antenna, respectively; The tilt angle of the reflecting antenna; d This represents the projected length of the phase center point of the direct antenna and the reflected antenna in the vertical direction. = 1+ 2. ; The satellite's elevation angle; n This represents the distance in the north direction from the mirror image of the phase center points of the direct antenna and the reflected antenna. d 1 represents the projected length of the phase center of the direct antenna and the reflective antenna in the horizontal direction, and 1= 2 .

[0077] In the slope scenario of this invention, the satellite elevation angle There is an angular deviation in the vertical height h (instrument height) between the phase center of the reflecting antenna and the reflecting surface. and distance deviation ,make , Then, perform error correction on the angle and distance, and then apply the new angle. ,high Replace the above geometric models respectively , The geometric model of the GNSS-R signal propagation path in the slope scene is obtained as follows:

[0078] Based on the above geometric model, the surface deformation monitoring results can be obtained using the differential GNSS-R surface deformation monitoring algorithm.

[0079] Specifically, taking satellite 1 as an example, the difference in propagation paths between the direct and reflected signals can be determined by the epoch (e.g., t). i The carrier phase single-difference equation (at time) represents:

[0080] The superscript indicates the satellite number. The path length of the reflected signal from satellite 1; Indicates the wavelength of the satellite band 1 signal; This indicates the carrier phase observation value received by the reflecting antenna from the L1 band of satellite 1; This indicates the carrier phase observation value received by the direct antenna from the L1 band of satellite 1; This is the difference in receiver clock bias between the direct signal and the reflected signal; , denoted by and respectively, representing the ambiguity of the carrier phase observations of the reflected and direct signals from satellite 1; c is the speed of light.

[0081] make , ,get:

[0082] in, These represent the angles at which satellite 1 and satellite 2 received the signal, respectively. These represent the elevation angles of satellite 1 and satellite 2, respectively. This is the difference in clock bias between the direct signal receiver and the reflected signal receiver; , Let represent the ambiguity of the carrier phase observations of the reflected and direct signals from satellite 2, respectively.

[0083] By subtracting the values ​​from satellite 1 and satellite 2, receiver clock errors can be eliminated. Further differential calculations between adjacent epochs yield the surface deformation monitoring results.

[0084] in, For surface deformation; For adjacent epochs, They are respectively The reflector antenna and direct antenna at the epoch received the carrier phase observation values ​​of the L1 band of satellite 1; They are respectively The reflector antenna and direct antenna at the epoch received the carrier phase observation values ​​of the L1 band of satellite 2; They are respectively The reflector antenna and direct antenna at the epoch received the carrier phase observation values ​​of the L1 band of satellite 1; They are respectively The reflector antenna and direct antenna at the epoch received the carrier phase observation values ​​of the L1 band of satellite 2.

[0085] In some possible embodiments, before inverting the surface deformation monitoring results by compensating for errors in the distance and angle based on the distance deviation and angle deviation, the method further includes: Real-time acquisition of meteorological sensor data and GNSS satellite elevation angle at the monitoring site; construction of a signal atmospheric refraction propagation time delay sub-model. The additional path distance error caused by meteorological disturbances is quantified based on the signal atmospheric refraction propagation delay sub-model. Linearly couple the additional path distance error to the distance deviation. In the middle, update the distance deviation.

[0086] Specifically, real-time meteorological sensor data such as atmospheric temperature, relative humidity, atmospheric pressure, and water vapor pressure are collected, and atmospheric refractive index is calculated. :

[0087] in, P Atmospheric pressure; T Absolute temperature; e It represents the water vapor pressure.

[0088] Additional path distance error caused by atmospheric refraction for:

[0089] in, This represents the length of the signal propagation path.

[0090] By linearly coupling the additional path distance error with the distance deviation, the total compensated distance error is obtained. :

[0091] Based on the total compensation distance error renew ,Right now This allows us to calculate the surface deformation monitoring results that take into account the coupling correction of atmospheric refraction errors.

[0092] This invention quantifies and compensates for additional path errors introduced by meteorological disturbances by constructing a signal atmospheric refraction propagation time delay sub-model, achieving dual-layer joint compensation of static geometric errors and dynamic environmental time-varying errors, reducing residual errors and monitoring drift caused by meteorological disturbances, and further improving the accuracy of surface deformation monitoring.

[0093] In some possible embodiments, the above method further includes: S105. The Kalman time-series filtering algorithm is used to smooth and denoise the distance and angle deviations obtained from continuous observation epochs, and an adaptive iterative update threshold is set to dynamically update the correlation coefficient of the error compensation model epoch by epoch.

[0094] Specifically, the distance deviation calculated by Kalman filtering for consecutive epochs is introduced. and angular deviation By performing smoothing and noise reduction, setting an iterative convergence threshold, and dynamically updating the correlation coefficient of the error compensation model epoch by epoch, adaptive iterative correction of time-series filtering can be achieved, suppressing long-term time-series monitoring drift caused by noise.

[0095] The following simulation test is conducted using a simplified slope as a smooth inclined plane with a fixed slope as an example. In this case, the equation of the reflecting surface is the straight line equation of the slope.

[0096] Assuming the monitored slope is 20°, and the coordinates of the intersection point G of the slope and the horizontal ground are (2.70 m, 0 m), combined with some parameters calibrated by the instrument (antenna mounting base), the coordinates of the phase center of the reflecting antenna are (0.19 m, 2.00 m), and the coordinates of the phase center of the direct antenna are (0 m, 2.18 m). The simulation results of the error compensation model are a distance deviation of 0.2353266 m and an angle deviation of 1.1737°. Figure 4 The figure shown is a schematic diagram of the simulation results of the error compensation model in this experiment.

[0097] With the positions of point G and the direct reflection antenna remaining unchanged, the following simulation results are obtained by successively increasing the slope: When the slope is 25°, the distance deviation is 0.2442041 m and the angle deviation is 0.9194°; when the slope is 30°, the distance deviation is 0.2513309 m and the angle deviation is 0.6861°; when the slope is 35°, the distance deviation is 0.2566409 m and the angle deviation is 0.4681°. The statistical simulation results are shown in Table 1 below. Table 1 shows that as the slope increases, the distance error increases, while the angle error decreases.

[0098] Table 1 Simulation results of the error compensation model for elevation angle variation

[0099] With a slope of 20° and the instrument's mounting position remaining constant, gradually increasing the instrument height yields the following simulation results: When the instrument height is 3 m, the distance deviation is 0.2350300 m and the angle deviation is 0.8831°; when the instrument height is 4 m, the distance deviation is 0.2348511 m and the angle deviation is 0.7078°; when the instrument height is 5 m, the distance deviation is 0.2347314 m and the angle deviation is 0.5906°. The statistical simulation results are shown in Table 2. Table 2 shows that as the instrument height increases, both the distance error and the angle error decrease slightly.

[0100] Table 2 Simulation results of the error compensation model for changes in instrument height

[0101] The simulation results from the two tests controlling different variables show that the distance deviation is relatively large in each case, while the angle deviation is relatively small, around one degree. This demonstrates that the error compensation model is crucial in slope scenarios.

[0102] Please see Figure 5 , Figure 5A schematic diagram of a ground-based GNSS-R surface deformation monitoring system for slope scenarios is provided as an embodiment of the present invention. The system includes: The parameter calibration module 510 is used to establish a two-dimensional plane rectangular coordinate system with the ground point of the observation station as the origin, and to calibrate environmental parameters and determine the phase center point of the direct antenna and the phase center point of the reflected antenna. The geometric modeling module 520 is used to establish the reflection surface equation of the slope in a two-dimensional Cartesian coordinate system based on environmental parameters, and to determine the mirror point of the phase center point of the reflecting antenna based on the reflection surface equation. Error calculation module 530 is used to establish an error compensation model based on the phase center point of the direct antenna, the phase center point of the reflected antenna, and the image point, and to determine the distance deviation and angle deviation. The deformation inversion module 540 is used to compensate for errors in the distance and angle of surface deformation monitoring based on the distance deviation and angle deviation, and to invert the surface deformation monitoring results.

[0103] The ground-based GNSS-R surface deformation monitoring system for slope-oriented scenarios described above and the ground-based GNSS-R surface deformation monitoring method for slope-oriented scenarios described above can be used as a reference for each other.

[0104] Figure 6 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 6 As shown, the electronic device may include a processor 610, a communication interface 620, a memory 630, and a communication bus 640. The processor 610, communication interface 620, and memory 630 communicate with each other via the communication bus 640. The processor 610 can call logical instructions in the memory 630 to execute the ground-based GNSS-R surface deformation monitoring method for slope scenarios provided in the above-described method embodiments.

[0105] Furthermore, the logical instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0106] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the ground-based GNSS-R surface deformation monitoring method for slope scenarios provided in the above-described method embodiments.

[0107] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, is implemented to perform a ground-based GNSS-R surface deformation monitoring method for slope scenarios provided by the methods described above.

[0108] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. 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 the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0109] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ground-based GNSS-R ground deformation monitoring method for a slope scene, characterized in that, include: A two-dimensional Cartesian coordinate system is established with the ground point of the observation station as the origin, and environmental parameters are calibrated to determine the phase center point of the direct antenna and the phase center point of the reflected antenna. Based on the environmental parameters, establish the reflection surface equation of the slope in the two-dimensional Cartesian coordinate system, and determine the mirror point of the phase center point of the reflecting antenna based on the reflection surface equation; An error compensation model is established based on the phase center point of the direct antenna, the phase center point of the reflected antenna, and the mirror point to determine the distance deviation and the angle deviation. Error compensation is performed on the distance and angle of the surface deformation monitoring based on the distance deviation and angle deviation, and the surface deformation monitoring results are obtained by inversion.

2. The ground-based GNSS-R surface deformation monitoring method for slope scenarios according to claim 1, characterized in that, The environmental parameters include at least the structural parameters of the antenna mounting base, the slope, the coordinates of the intersection of the slope and the ground, and the location of the observation station.

3. The ground-based GNSS-R surface deformation monitoring method for slope scenarios according to claim 2, characterized in that, The step of establishing the reflection surface equation of the slope in the two-dimensional Cartesian coordinate system based on the environmental parameters, and determining the mirror point of the phase center point of the reflecting antenna based on the reflection surface equation, includes: The slope is simplified to a smooth inclined plane with a fixed slope. Based on the slope and the coordinates of the intersection point between the slope and the ground, the equation of the straight line of the slope in the two-dimensional plane rectangular coordinate system is determined as the equation of the reflecting surface. Based on the equation of the straight line, the mirror point of the phase center point of the reflective antenna is determined by the symmetry relationship.

4. The ground-based GNSS-R surface deformation monitoring method for slope scenarios according to claim 3, characterized in that, The step of establishing an error compensation model based on the phase center point of the direct antenna, the phase center point of the reflected antenna, and the image point to determine the distance deviation and angle deviation includes: Determine a first distance between the phase center point of the direct antenna and the mirror point, and a second distance between the phase center point of the reflective antenna and the mirror point; determine the distance deviation based on the difference between the first distance and the second distance. Determine the first angle between the equation of the line containing the phase center point of the direct antenna and the mirror point and the horizontal axis of the two-dimensional Cartesian coordinate system, and the second angle between the equation of the line containing the phase center point of the reflective antenna and the mirror point and the horizontal axis. Determine the angle deviation based on the difference between the first angle and the second angle.

5. The ground-based GNSS-R surface deformation monitoring method for slope scenarios according to claim 2, characterized in that, The step of establishing the reflection surface equation of the slope in the two-dimensional Cartesian coordinate system based on the environmental parameters, and determining the mirror point of the phase center point of the reflecting antenna based on the reflection surface equation, includes: The slope is subjected to gridded discrete sampling to obtain a set of discrete sampling points, which includes the local slope elevation value and local slope inclination at each grid point. Based on the set of discrete sampling points, the continuous surface equation of the slope is fitted using the bilinear interpolation method as the equation of the reflecting surface; Based on the environmental parameters, a local specular reflection point that satisfies the law of reflection is searched on the equation of the continuous surface. A tangent plane is determined in the neighborhood of the local specular reflection point. The mirror point of the phase center point of the reflecting antenna is determined based on the tangent plane.

6. The ground-based GNSS-R surface deformation monitoring method for slope scenarios according to claim 4, characterized in that, Before performing error compensation on the distance and angle of the surface deformation monitoring based on the distance deviation and the angle deviation to obtain the surface deformation monitoring results, the method further includes: Real-time acquisition of meteorological sensor data and GNSS satellite elevation angle at the monitoring site; construction of a signal atmospheric refraction propagation time delay sub-model. The additional path distance error caused by meteorological disturbances is quantified based on the atmospheric refraction and propagation delay sub-model of the signal. The additional path distance error is linearly coupled to the distance deviation. In the process, update the distance deviation.

7. The ground-based GNSS-R surface deformation monitoring method for slope scenarios according to claim 1, characterized in that, The method further includes: The Kalman time-series filtering algorithm is used to smooth and denoise the distance and angle deviations obtained from continuous observation epochs, and an adaptive iterative update threshold is set to dynamically update the correlation coefficient of the error compensation model epoch by epoch.

8. A ground-based GNSS-R surface deformation monitoring system for slope scenarios, characterized in that, include: The parameter calibration module is used to establish a two-dimensional Cartesian coordinate system with the ground point of the observation station as the origin, and to calibrate environmental parameters to determine the phase center point of the direct antenna and the phase center point of the reflected antenna. The geometric modeling module is used to establish the reflection surface equation of the slope in the two-dimensional Cartesian coordinate system based on the environmental parameters, and to determine the mirror point of the phase center point of the reflecting antenna based on the reflection surface equation. The error calculation module is used to establish an error compensation model based on the phase center point of the direct antenna, the phase center point of the reflected antenna, and the mirror point, and to determine the distance deviation and angle deviation. The deformation inversion module is used to compensate for errors in the distance and angle of the surface deformation monitoring based on the distance deviation and the angle deviation, and to invert the surface deformation monitoring results.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the ground-based GNSS-R surface deformation monitoring method for slope-oriented scenarios as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the ground-based GNSS-R surface deformation monitoring method for slope-oriented scenarios as described in any one of claims 1 to 7.

Images