Method, device, equipment and medium for remote sensing monitoring of transmission line sag

Abstract

The present application relates to the technical field of remote sensing monitoring of power transmission lines, and in particular to a method, apparatus, equipment, and medium for remote sensing monitoring of transmission line sag, wherein the method comprises: obtaining the positioning deviation of a synthetic aperture radar image to correct the geometric positioning error of the transmission line imaging; determining the radar coordinates of the mounting points at both ends of the transmission line and their projection points on a given ellipsoid reference surface, and extracting the radar coordinates of the center point of the transmission line scattering spot; calculating the sag state of the transmission line at the time of image capture based on the mounting points at both ends of the transmission line and their projection points on a given ellipsoid reference surface, and the center point of the transmission line scattering spot. Thus, the problem of how to utilize the imaging characteristics of the transmission line scattering spot to accurately extract the three-dimensional state of the transmission line sag is solved. The method can be embedded in a data center or a remote sensing sensor platform through electronic equipment such as a computer to achieve real-time monitoring, evaluation, and early warning of the transmission line sag.

Description

Technical Field

[0001] The present application relates to the technical field of remote sensing monitoring of overhead transmission lines, and in particular to a method, device, equipment and medium for remote sensing monitoring of transmission line sag. Background Art

[0002] As modern power systems continue to expand, the length and complexity of transmission lines are also increasing. SAR (Synthetic Aperture Radar) is an active microwave sensor that operates continuously around the clock, in all weather conditions and is unaffected by sunlight. Using SAR remote sensing imaging detection technology, the sag of transmission conductors and ground wires can be monitored in real time in harsh climates. It can identify abnormal sag and disconnected conductors caused by factors such as icing, oscillation, and hardware damage. This technology is expected to improve the reliability and robustness of the safe operation and maintenance of overhead transmission lines.

[0003] Current SAR remote sensing technologies primarily utilize interferometric SAR (SAR) technology to monitor the deformation of the ground surface surrounding transmission towers and identify geological hazards around them by combining SAR imagery time-series analysis with deep learning techniques. However, these technologies neglect the imaging characteristics of overhead transmission lines within SAR images. While theoretically, it is possible to extract the sag of transmission conductors and ground wires, the periodic variations in the scattered speckle texture features of transmission lines in time-series SAR images reflect changes in the sag state of these lines. However, a lack of quantitative evaluation theories and methods prevents quantitative analysis of transmission line imaging characteristics in SAR images, making it difficult to extract 3D information about the underlying state of transmission conductors and ground wires from 2D SAR images. Summary of the Invention

[0004] This application provides a method, apparatus, device, and medium for remotely sensing the sag of power transmission lines. This method addresses the problem of effectively utilizing the imaging characteristics of the scattering spots of power transmission conductors and ground wires in synthetic aperture radar images to accurately extract information on sag changes in power transmission conductors and ground wires. Given the high consistency of the scattering characteristics of power transmission conductors and ground wires in radar images, this application uses power transmission conductors as an example to discuss the relevant technical methods. These methods are also suitable for extracting sag information from overhead power transmission line ground wires.

[0005] A first aspect of the present application provides a method for remote sensing monitoring of transmission line sag, comprising the following steps: obtaining a positioning deviation of a synthetic aperture radar image to correct a geometric positioning error in transmission line imaging; determining the radar coordinate system coordinates of the mounting points at both ends of the transmission line and their projection points on a given ellipsoid reference surface, and extracting the radar coordinate system coordinates of the center point of the transmission line scattering spot; and calculating the sag state of the transmission line at the time of image capture based on the mounting points at both ends of the transmission line and their projection points on the given ellipsoid reference surface and the center point of the transmission line scattering spot.

[0006] Optionally, determining the positioning deviation of the synthetic aperture radar image based on the ground control point includes: obtaining the actual measured geographic coordinates of the ground control point; using the geographic coordinates and the range Doppler equation to calculate the geometric positioning coordinates of the actual measured geographic coordinates of the ground control point in the radar coordinate system; determining the positioning deviation value of the synthetic aperture radar image based on the radar scattering imaging center point coordinates and the geometric positioning coordinates of the ground control point, wherein the radar scattering imaging center point coordinates of the ground control point are the coordinates of the scattering intensity extreme point within a preset range of the ground control point target, and the positioning deviation value of the radar image is used to correct the geometric positioning of the synthetic aperture radar image.

[0007] Optionally, the radar coordinate system coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid are determined based on the corrected geometric positioning parameters, including: obtaining imaging parameters of a synthetic aperture radar image; determining the coordinates of the mounting points at both ends of the transmission line based on the imaging parameters, positioning deviation and range Doppler model; defining an ellipsoid datum of a given elevation, wherein the given elevation is lower than the lowest point of suspension of the transmission line, and determining the geographic coordinates of corresponding points of the mounting points at both ends of the transmission line vertically projected onto the ellipsoid datum of the given elevation; determining the radar coordinate system coordinates of the mounting points at both ends of the transmission line and corresponding points of the mounting points at both ends projected onto the ellipsoid datum of the given elevation based on the imaging parameters, positioning deviation and range Doppler model.

[0008] Optionally, based on the radar coordinate system coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid, and the coordinates of the center point of the scattering spot of the transmission line, an expression of the transmission line in the radar coordinate system and an elevation function are constructed, and the sag state of the transmission line at the time of synthetic aperture radar image shooting is calculated, including: obtaining the transmission line expression of the transmission line at the time of synthetic aperture radar image shooting based on the coordinates of the center point of the scattering spot of the transmission line and the radar coordinate system coordinates of the hanging points at both ends of the transmission line; constructing a straight line equation based on the radar coordinate system coordinates of the projection points of the mounting points at both ends of the transmission line on an ellipsoid reference surface of a given elevation, and obtaining the elevation function of the transmission line in combination with the transmission line expression; and determining the sag function of the transmission line at the time of radar image shooting in three-dimensional space through the range Doppler equation based on the transmission line expression obtained at the time of radar image shooting and the calculated elevation function of the transmission line.

[0009] Optionally, in the plane of the radar coordinate system, the transmission line expression of the transmission line at the time of synthetic aperture radar image capture is obtained based on the coordinates of the center point of the transmission line scattering spot and the radar coordinate system coordinates of the hanging points at both ends of the transmission line, including: obtaining the coordinates of the center point of the transmission line scattering spot as the coordinates of the extreme point of the scattering intensity within a preset range of the scattering spot; using the radar coordinate system coordinates of the center point of the transmission line scattering spot and the hanging points at both ends of the line, and under the condition that the tangent equation of the sag state function at the center point of the scattering spot is zero or there is an extreme value in the distance direction, obtaining the transmission line expression of the transmission line in the radar coordinate system, the transmission line expression being a parabolic equation or a hyperbolic equation.

[0010] Optionally, a straight line equation is constructed based on the radar coordinate system coordinates of the projection points of the mounting points at both ends of the transmission line on the ellipsoid datum plane at a given elevation, and the elevation function of the transmission line is obtained in combination with the transmission line expression, including: obtaining the geographic coordinates of the projection points of the mounting points at both ends of the transmission line on the ellipsoid datum plane at a given elevation, and obtaining the coordinates of the two projection points in the radar coordinate system through the range Doppler equation, and constructing the straight line equation connecting the two projection points; solving the range deviation function between the straight line equation of the two projection points and the transmission line expression point by point along the azimuth direction, and obtaining the incident angle and range resolution parameters of the synthetic aperture radar image; and determining the elevation function of the transmission line based on the range deviation function, the incident angle and the range resolution parameters.

[0011] Optionally, the sag state of the transmission line at the time of synthetic aperture radar image capture is calculated according to the transmission line expression and the elevation function, including: solving the three-dimensional spatial sag state of the transmission line in the geographic coordinate system according to the transmission line expression, the elevation function, the range Doppler equation and the ellipsoid equation; obtaining the sag state of the transmission line in the local rectangular coordinate system based on the three-dimensional spatial sag state of the transmission line in the geographic coordinate system and the local rectangular coordinate system conversion parameters, and calculating its maximum sag value and minimum sag value.

[0012] A second aspect of the present application provides an apparatus for remotely sensing and monitoring the sag of a transmission line, comprising: a determination module for determining a positioning deviation of a synthetic aperture radar image based on a ground control point; a correction module for correcting the geometric positioning error of the synthetic aperture radar image based on the positioning deviation, determining the radar coordinate system coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid based on the corrected geometric positioning error, and extracting the coordinates of the center point of the scattering spot of the transmission line; a calculation module for constructing an expression and an elevation function of the transmission line in the radar coordinate system based on the radar coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid and the coordinates of the center point of the scattering spot of the transmission line, and calculating the sag state of the transmission line at the time of shooting the synthetic aperture radar image based on the transmission line expression and the elevation function.

[0013] Optionally, the determination module is further used to obtain the actual measured geographic coordinates of the ground control point in the synthetic aperture radar image; use the geographic coordinates and the range Doppler equation to calculate the geometric positioning coordinates of the actual measured geographic coordinates of the ground control point in the radar coordinate system; determine the positioning deviation value of the synthetic aperture radar image based on the radar scattering imaging center point coordinates and the geometric positioning coordinates of the ground control point, wherein the radar scattering imaging center point coordinates of the ground control point are the coordinates of the scattering intensity extreme point within the preset range of the ground control point target, and the positioning deviation value of the radar image is used to correct the geometric positioning of the synthetic aperture radar image.

[0014] Optionally, the correction module is further used to correct the geometric positioning error of the synthetic aperture radar image according to the positioning deviation, and solve the corresponding radar coordinate system coordinates through the range Doppler equation according to the geographical coordinates of the mounting points at both ends of the transmission line and the geographical coordinates of the projection points on the given reference ellipsoid, and extract the coordinates of the center point of the scattering spot of the transmission line.

[0015] Optionally, the calculation module is further used to construct an expression and elevation function of the transmission line in the radar coordinate system based on the radar coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid, and the coordinates of the center point of the scattering spot of the transmission line. Based on the expression and elevation function of the transmission line, the range-Doppler equation is used to calculate the set of geographic coordinate points of the sag state of the transmission line at the time the synthetic aperture radar image is taken.

[0016] Optionally, the calculation module is further used to obtain the coordinates of the center point of the scattering spot of the transmission line as the coordinates of the extreme point of the scattering intensity within a preset range of the scattering spot; using the radar coordinate system coordinates of the center point of the scattering spot of the transmission line and the mounting points at both ends of the line, under the condition that the tangent equation of the sag state function at the center point of the scattering spot is zero or there is an extreme value in the distance direction, obtain the transmission line expression of the transmission line in the radar coordinate system, and the transmission line expression is a parabolic equation or a hyperbolic equation.

[0017] Optionally, the calculation module is further used to obtain the projection points of the mounting points at both ends of the transmission line on the ellipsoidal datum plane of a given elevation, and obtain the coordinates of the two projection points in the radar coordinate system through the range Doppler equation, and construct the equation of a straight line connecting the two projection points; solve the range deviation function between the straight line equation of the two projection points and the transmission line expression according to the azimuth, and obtain the incident angle and range resolution of the synthetic aperture radar image; determine the elevation function of the transmission line based on the range deviation function, the incident angle and the range resolution.

[0018] Optionally, the calculation module is further used to solve the three-dimensional sag state of the transmission line in the geographic coordinate system based on the transmission line expression, elevation function, range Doppler equation and ellipsoid equation; based on the three-dimensional sag state of the transmission line in the geographic coordinate system and the local rectangular coordinate system conversion parameters, obtain the sag state of the transmission line in the local rectangular coordinate system, and calculate its maximum sag point and minimum sag value.

[0019] The third aspect of the present application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and runnable on the processor. The processor executes the program to implement the method for remote sensing monitoring of transmission line sag as described in the above embodiment.

[0020] The fourth aspect of the present application provides a computer-readable storage medium having a computer program or instruction stored thereon. When the computer program or instruction is executed, it is used to implement the method for remote sensing monitoring of transmission line sag as described in the above embodiment.

[0021] Therefore, this application has at least the following beneficial effects:

[0022] The embodiments of the present application determine the locations of the mounting points at both ends of the transmission line and the coordinates of the center of the scattering spot based on synthetic aperture radar images of the transmission line. This allows for accurate monitoring of the changing sag state of the transmission line. Using the mounting points and a known reference plane to perform a three-dimensional inversion of the transmission line, the accuracy of the transmission line sag calculation can be achieved to the decimeter or even centimeter level, helping to improve the timeliness and accuracy of safety monitoring of overhead transmission line facilities. In the future, a transmission line sag monitoring module can be integrated into satellite-borne or drone-borne SAR platforms to implement edge computing capabilities. The calculation and analysis of the transmission line sag state can be performed simultaneously with the SAR sensor capturing the image, and the calculation and analysis results can be directly transmitted to the power grid operation and maintenance team, greatly increasing the real-time nature of remote sensing monitoring. This is particularly suitable for power safety operation and maintenance in remote, complex terrain, and harsh environments with inconvenient communications.

[0023] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0025] Figure 1 A flowchart of a method for remotely sensing and monitoring transmission line sag according to an embodiment of the present application;

[0026] Figure 2A schematic diagram of the coordinates of the imaging center point of the image conductor scattering spot provided according to an embodiment of the present application;

[0027] Figure 3 A three-dimensional example diagram of a transmission line in a local coordinate system according to an embodiment of the present application;

[0028] Figure 4 The display result of the transmission line expression and elevation function in the image provided by the embodiment of the present application;

[0029] Figure 5 This is an example diagram of remote sensing monitoring of transmission line sag according to an embodiment of the present application;

[0030] Figure 6 A schematic diagram of the time sequence change of the sag of a transmission line provided according to an embodiment of the present application;

[0031] Figure 7 This is an example diagram of a device for remotely sensing and monitoring the sag of a transmission line according to an embodiment of the present application;

[0032] Figure 8 Schematic diagram of the structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0034] The following describes the method, apparatus, device, and medium for remotely sensing the sag of a transmission line according to an embodiment of the present application with reference to the accompanying drawings. In response to the problems mentioned in the above background technology, the present application provides a method for remotely sensing the sag of a transmission line. In this method, the positions of the mounting points at both ends of the transmission line and the coordinates of the center point of the scattering spot are determined based on the synthetic aperture radar image of the transmission line, so that the changing sag state of the transmission line can be accurately monitored. By using the mounting points and a known reference plane to perform a three-dimensional inversion of the transmission line, the accuracy of the transmission line sag calculation can be achieved to the decimeter level, which helps to improve the safety and stability of power facilities.

[0035] Specifically, Figure 1 A flowchart of a method for remotely sensing and monitoring transmission line sag provided in an embodiment of the present application.

[0036] like Figure 1 As shown, the method for remote sensing monitoring of transmission line sag includes the following steps:

[0037] In step S101, the positioning deviation of the synthetic aperture radar image is determined according to the ground control points.

[0038] In the embodiment of the present application, the transmission wires are responsible for transmitting electrical energy, while the transmission ground wires mainly play a protective role against lightning strikes and some of the internally wrapped optical cables have communication capabilities to ensure the safe operation of the transmission lines.

[0039] In an embodiment of the present application, the periodic changes in the texture features of the scattered speckles of the transmission line in the time-series SAR image reflect the changes in the sag state of the transmission line. In this embodiment of the present application, the scattering speckles formed by the reflection characteristics of the transmission line in the SAR image can be used to invert the three-dimensional information of the transmission line based on the changes in the range and azimuth positions of the scattering speckles of the transmission line in the SAR image at different times and the geographic coordinates of the mounting points at both ends of the transmission line. This can achieve decimeter-level accuracy in monitoring the sag changes of the transmission line, thereby realizing the monitoring of the sag changes of the transmission line. Specifically,

[0040] In one embodiment of the present application, determining the positioning deviation of a synthetic aperture radar image includes: obtaining the actual measured geographic coordinates of a control point in the synthetic aperture radar image; calculating the geometric positioning coordinates of the actual measured geographic coordinates of the ground control point in the radar coordinate system using the geographic coordinates of the control point and the range Doppler equation; and determining the positioning deviation value of the synthetic aperture radar image based on the coordinates of the center point of the radar scattering imaging of the control point and the geometric positioning coordinates, wherein the coordinates of the center point of the radar scattering imaging of the control point are the coordinates of the extreme point of the scattering intensity within a preset range of the control point target.

[0041] In the embodiment of the present application, the target preset range can be set according to actual conditions, such as the 20*20 window in the following embodiment, without specific limitation.

[0042] It is understood that the embodiment of the present application can actually measure the high-precision geographic coordinates of the ground control point C, and mark the ellipsoid coordinates of the point as C (B,L,H) ; Use SAR image imaging parameters and range Doppler model to obtain the sub-pixel pixel coordinates C of point C in the SAR coordinate system g(a,r) Through more than 10 times oversampling, the maximum value method is used to obtain the sub-pixel precision coordinates C of the extreme point of scattering intensity within the preset range of the control point C target. s(a,r) ;

[0043] In this embodiment, the sub-pixel center coordinates C are calculated by comparing the control point C using the Doppler model and the measured geographic coordinates. g(a,r) , and the sub-pixel center coordinate C obtained from the extreme point of scattering intensity s(a,r) , obtain the deviation of the sub-pixel accuracy of the SAR image azimuth and range directions ε (a,r) :

[0044] ε( a,r )=C s ( a,r )-C g ( a,r )

[0045] For ease of understanding, the present embodiment can combine the three-dimensional point cloud of the wire in a certain area to actually measure the high-precision geographic coordinates of a street lamp C at the ground image control point. The positioning deviation of the synthetic aperture radar image in the embodiment of the present application is explained in detail:

[0046] The high-precision geographic coordinates of a street lamp C, a ground image control point, are actually measured in the three-dimensional point cloud of the wire. The ellipsoid coordinates of this point are marked as C( B,L,H );

[0047] The rectangular position vector of the geocentric space of this point is denoted as R C (C X ,C Y ,C z ) T ;

[0048] Corresponding control point C imaging time t i The instantaneous position vector of the SAR satellite at time t is in the geocentric rectangular coordinate system, and the position vector R S Denoted as (S X ,S Y ,S Z ) T ;

[0049] R C With R S Satisfies the range Doppler equation:

[0050] R i 2 -(S X -C X ) 2 +(S Y -C Y ) 2 +(S Z -C Z ) 2 =0

[0051]

[0052] Among them, V S is the velocity vector of the SAR sensor S, which contains three directional components: and λ is the radar wavelength, f d t i The frequency offset of the radar echo signal at the moment, R iThen it is point Ct i Slant range to the satellite at any moment;

[0053] Using the SAR satellite's cm-level precision orbit data, R i It can be accurately positioned to the cm level through iterative solution, and the corresponding imaging time t i The accuracy can be better than 0.1 nanosecond;

[0054] C (X,Y,Z) According to the above range Doppler equation, find the R and t corresponding to this point i , and calculate the reference coordinate value C in the radar coordinate system (a,r) , accurate to the sub-pixel level, as shown below:

[0055]

[0056] Among them, R0 is the slant distance of the close point corresponding to the first column of pixels in the SAR image, ρ r is the radar azimuth spatial resolution. t0 is the starting sampling time of the first row of pixels in the SAR image in azimuth, Az is the number of azimuth views, and PRF is the radar pulse repetition frequency.

[0057] Through local oversampling, such as the reference point C coordinate value (C a ,C r ) as the center, such as selecting a 20*20 window, oversampling 10 times, and using the maximum search method under the oversampled window to traverse and find the point with the maximum scattering intensity, the radar scattering imaging center point C of the reference point C is obtained. g Pixel coordinates

[0058] Compare the sub-pixel center coordinates (C a ,C r ), and the sub-pixel center coordinates obtained by the maximum search method Obtaining the positioning deviation ε of the sub-pixel accuracy of SAR images (a,r) =C s(a,r) -C g(a,r) , by calculating the positioning deviation of a certain area under the TSX image above

[0059] In step S102, the geometric positioning error of the synthetic aperture radar image is corrected according to the positioning deviation, and the radar coordinate system coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid are determined according to the geometric positioning parameters of the corrected synthetic aperture radar image.

[0060] Furthermore, the coordinates of the mounting points at both ends of the transmission line and the coordinates of the projection points of the mounting points at both ends of the transmission line are determined according to the positioning deviation of the synthetic aperture radar image, including: obtaining imaging parameters of the synthetic aperture radar image; determining the coordinates of the mounting points at both ends of the transmission line according to the imaging parameters, positioning deviation and range Doppler model; defining an ellipsoid reference plane of a given elevation, wherein the given elevation is lower than the lowest point of suspension of the transmission line, and determining the geographic coordinates of corresponding points of the mounting points at both ends of the transmission line vertically projected onto the ellipsoid reference plane of the given elevation; determining the radar coordinate system coordinates of the mounting points at both ends of the transmission line and the corresponding points of the mounting points at both ends projected onto the ellipsoid reference plane of the given elevation according to the imaging parameters, the positioning deviation and the range Doppler model.

[0061] On the basis of the above embodiments, the embodiments of the present application can utilize SAR image imaging parameters and range Doppler model, and take into account the positioning deviation ε of the SAR image sub-pixel accuracy. (a,r) , find the coordinates P of the mounting point P at one end of the wire (a,r) ; Using SAR image parameters and range Doppler model, and taking into account the positioning deviation of SAR image sub-pixel accuracy ε (a,r) , find the coordinates Q of the mounting point Q at the other end of the wire (a,r) .

[0062] In the embodiment of the present application, the mounting points P and Q at both ends can also be projected onto the ellipsoid with an elevation of h to obtain P g , Q g Two points and their projection coordinates P in the radar coordinate system g(a,r) ,Q g(a,r) , specifically including the following steps:

[0063] Define an ellipsoidal datum at a given elevation, where the given elevation is lower than the lowest point of the transmission line, which is denoted as H0; use SAR image imaging parameters and range Doppler model, and take into account the positioning deviation ε of the SAR image sub-pixel accuracy (a,r) , determine the coordinates of the corresponding projection points of the mounting points at both ends of the transmission line vertically projected onto the ellipsoid reference plane of a given elevation;

[0064] Find the projection point P of the mounting point P at one end of the wire on the ellipsoid g The projection point coordinates P g(a,r) ; Using SAR image parameters and range Doppler model, and taking into account the positioning deviation of SAR image sub-pixel accuracy ε (a,r) , find the projection coordinates Q of the mounting point Q at one end of the wire (a,r) ;

[0065] Furthermore, the embodiment of the present application can also obtain the coordinates of the center point of the scattering spot of the transmission line. That is, the embodiment of the present application can oversample the pixel at the center point of the scattering spot of the transmission line by more than 10 times through the local oversampling method; based on the oversampling data and the maximum value search method, the coordinates S of the center point of the scattering spot of the transmission line in the SAR image are obtained. (a,r) ;like Figure 2 The black dot shown is S (a,r) , respectively showing the scattering spots of the F transmission line in the period of 20130427, 20130702, 20130815, and 20130906. Figure 2 It can be seen that the center point of the scattering spot is different in each image, that is, the performance is inconsistent when the synthetic aperture radar image is taken at different times.

[0066] In step S103, an expression for the transmission line in the radar coordinate system and an elevation function are constructed based on the radar coordinates of the mounting points at both ends of the transmission line and their projections on a given reference ellipsoid, and the coordinates of the center point of the scattering spot of the transmission line. The sag state of the transmission line at the time of synthetic aperture radar image capture is calculated based on the expression for the transmission line and the elevation function.

[0067] It is understandable that in the embodiment of the present application, the transmission line expression of the transmission line at the time of synthetic aperture radar image capture can be obtained based on the coordinates of the center point of the transmission line scattering spot and the radar coordinate system coordinates of the suspension points at both ends of the transmission line; a straight line equation is constructed based on the radar coordinate system coordinates of the projection points of the mounting points at both ends of the transmission line on the ellipsoid reference plane at a given elevation, and the elevation function of the transmission line is obtained by combining the transmission line expression; based on the transmission line expression obtained at the time of radar image capture and the calculated elevation function of the transmission line, the sag function of the transmission line at the time of radar image capture in three-dimensional space is determined using the range Doppler equation. Specifically:

[0068] The embodiment of the present application can use the range Doppler model and SAR imaging parameters, combined with the transmission line expression f(a) in the radar coordinate system and the elevation function expression H(a), to obtain the point set i in the transmission line geographic coordinate system. [XYZ] ; Among them, the elevation function expression H(a) is introduced in detail in the following embodiments.

[0069] In one embodiment of the present application, obtaining the elevation function of the transmission line in a radar coordinate system includes: obtaining the geographic coordinates of the projection points of the mounting points at both ends of the transmission line on an ellipsoidal reference plane of a given elevation, obtaining the coordinates of the two projection points in the radar coordinate system through a range-Doppler equation, and constructing an equation of a straight line connecting the two projection points; solving the range deviation function between the straight line equation of the two projection points and the expression of the transmission line point by point along the azimuth direction, and obtaining the incident angle and range resolution parameter of the synthetic aperture radar image; and determining the elevation function of the transmission line based on the range deviation function, the incident angle, and the range resolution parameter.

[0070] In the embodiment of the present application, connect P g(a,r) , Q g(a,r) Two points, get the straight line equation g(a), where a is the azimuth coordinate of any point on the line, such as Figure 4 As shown by the white straight line in the middle. The embodiment of the present application can combine the straight line equation g(a) and S (a,r) , to obtain the transmission line elevation function H(a) in the radar coordinate system, specifically including the following steps:

[0071] When the expression f(a) of the transmission line i in the radar coordinate system is defined as a quadratic polynomial function, a is the azimuth coordinate of any point on the line in the radar coordinate system, and f(a) is the range coordinate of any point a on the line i in the radar coordinate system; based on P (a,r) and Q (a,r) and S (a,r) , calculate the polynomial coefficients β1, β2, β3, and get f(a). The F conductor f in the TSX image of 20130427 F (a) If Figure 4 The white curve in the middle;

[0072] Furthermore, the embodiment of the present application can solve the range deviation function p(a) between the straight line equation H(a) of the projection point coordinates and the transmission line expression f(a) based on the azimuth, and obtain the incident angle and range resolution of the synthetic aperture radar image; and determine the elevation function of the transmission line based on the range deviation function, the incident angle, and the range resolution, as follows:

[0073] Solve the distance deviation function p(a) between g(a) and f(a) according to the azimuth:

[0074] p(a)=|g(a)-f(a)|

[0075] By obtaining the incident angle η and range resolution δ in the SAR imaging parameters r ;

[0076] Based on the distance deviation function p(a), η and δ are introduced r , calculate the transmission line elevation function H(a) in the radar coordinate system:

[0077] H(a)=H0+p(a)*δ r / cosη

[0078] Furthermore, according to the transmission line expression, elevation function, range Doppler equation and ellipsoid equation, the point set of the transmission line in the geographic coordinate system is solved.

[0079] Specifically, the embodiment of the present application can use N = 1 to 5 azimuth pixels as the step size, that is, a = a + N, and substitute f(a) and H(a) to obtain the three-dimensional point set of the transmission i in the SAR image: i [af(a)H(a)] ; And use the range Doppler model and SAR imaging parameters to obtain the point set in the geographical coordinate system of transmission line i: i [BLH)] , transform the point set of the transmission line i in the geographic coordinate system into the spatial rectangular coordinate system to obtain the target point set i [XYZ] , achieving precise positioning of the imaging points of the transmission lines in the SAR images and inversion of the three-dimensional model, thereby realizing the construction of SAR two-dimensional data into three-dimensional form.

[0080] Furthermore, a local rectangular coordinate system is established, and the lowest point of the transmission line point set is defined as the origin, and the mounting point P (X,Y,Z) and Q (X,Y,Z) The line connecting XOY is the M axis, and the line perpendicular to the direction of the line is the N axis; the point set i in the geographic coordinate system of the transmission line is [XYZ] Transform to local rectangular coordinate system i [mn] ; In the local rectangular coordinate system, i [mn] Fitting to get the expression L(m) of transmission line i; connect P (m,n) , Q (m,n) Two points are defined to obtain the equation of the line k(m); the sag function of the transmission line at the time of SAR imaging is calculated as q(m) = k(m) - L(m). In actual execution, when the expression L(m) is defined as a quadratic polynomial function (i.e., a parabola equation), where m is the coordinate of any point on the conductor in the local coordinate system along the transmission line, and L(m) is the vertical coordinate of any point on the conductor, the polynomial coefficients β1, β2, and β3 are calculated. When the expression L(m) is defined as a catenary equation (i.e., a hyperbola equation), where m is the coordinate of any point on the conductor in the local coordinate system along the transmission line, and L(m) is the vertical coordinate of any point on the conductor, the catenary equation coefficient δ1 is calculated.

[0081] Furthermore, the embodiment of the present application establishes a local rectangular coordinate system, defines the lowest point of the transmission line point set as the origin, and the mounting point P(X,Y,Z) and Q (X,Y,Z) The line connecting XOY is the M axis, and the line perpendicular to the line is the N axis. Figure 3 As shown; the point set i in the geographic coordinate system of the transmission line [XYZ] Transform to local rectangular coordinate system i [mn] :

[0082] m i =(X i -X0) / cosα

[0083] n i =Z i -Z0

[0084] Where α is the angle between the transmission lines in the XOY plane, X0, Z0 are the coordinate values ​​of the origin in the geographic coordinate system, X i , Z i is the coordinate value of any point in the geographic coordinate system, m i , n i is the coordinate value of the point in the local coordinate system; in the local rectangular coordinate system, i [mn] Fitting to get the expression L(m) of transmission line i; connect P (m,n) , Q (m,n) Two points, get the straight line equation k(m); calculate the transmission line sag function q(m) = k(m)-L(m). Figure 4 The figure shows the expression L(m) of the transmission line A in the local coordinate system calculated based on the scattering center point and the mounting points P and Q of the TSX image.

[0085] It is understandable that the embodiment of the present application obtains the sag state of the transmission line in the local rectangular coordinate system based on the three-dimensional sag state of the transmission line in the geographic coordinate system and the local rectangular coordinate system conversion parameters, and calculates its maximum sag point and minimum sag value. Specifically, in the local rectangular coordinate system determined by the mounting points at both ends of the wire, based on the established equation of the transmission line, the SAR imaging time T is obtained at different times. i The transmission line sag function q Ti (m); respectively calculate the special sag value of the transmission line sag function at different SAR imaging times. When m is found, the maximum sag point is obtained, and the corresponding That is the maximum sag. When m=0, This is the lowest point of the sag.

[0086] The following combination Figure 5 The application of the remote sensing monitoring method for transmission line sag in long-time series images in the embodiment of the present application is described in detail. The specific steps are as follows:

[0087] Step S1: Generate a time baseline map for the SAR data set, select the date with each baseline less than 150m and in the middle of the time series as the main image, and align all SAR images with the main image; use the ground image control points to correct the SAR image positioning deviation, and calculate the imaging coordinates P of the mounting points P and Q at both ends of the transmission line i in the radar coordinate system. (a,r) ,Q (a,r) ;

[0088] Step S2: T i The SAR image at the moment is used to obtain the center point S of the scattering spot of the transmission line based on the maximum value method. (a,r) Sub-pixel accuracy coordinates of radar coordinate system;

[0089] Step S3: Calculate the projection point P of the hanging points at both ends of the wire on the ellipsoid with an elevation of h g and Q g Sub-pixel precision radar imaging coordinates P g(a,r) ,Q g(a,r) , and construct the straight line equation g(a) connecting the two points in the radar coordinate system;

[0090] Step S4: For each image, obtain the time scale T at the time of imaging i ; Joint P (a,r) ,Q (a,r) And based on T i S extracted from SAR images at any moment (a,r) , obtain the transmission line expression f(a) in the radar coordinate system, calculate the pixel interval from f(a) to the straight line equation g(a) along the azimuth direction, and obtain the transmission line elevation function H(a) in the radar coordinate system;

[0091] Step S5: In the local rectangular coordinate system determined by the mounting points at both ends of the wire, establish the equation of the transmission wire and calculate the different SAR imaging times T i The transmission line sag function The special sag values ​​of the transmission line sag function at different SAR imaging times are obtained respectively. When m is found, the maximum sag point is obtained, and the corresponding That is the maximum sag value. When m=0, This is the minimum sag value.

[0092] Specifically, the special sag value of the transmission line sag function at different SAR imaging times is obtained, such as the value of m=0n=0, which is the time-series minimum sag value of the transmission line; when the first-order derivative of the conductor sag function is zero, the point is the maximum sag point; when m is at the midpoint of P and Q, it is the span center sag value of the transmission line. Figure 6As shown in the figure, the sag change time series of transmission line A in 65 periods is shown. There is an obvious seasonal change in the figure, where HC_min represents the minimum sag value of transmission line A. The sag change of transmission line A in 5 years is about 2m.

[0093] According to the method for remote sensing monitoring of transmission line sag proposed in the embodiment of the present application, the positions of the mounting points at both ends of the transmission line and the coordinates of the center point of the scattering spot are determined based on the synthetic aperture radar image of the transmission line, so that the changing sag state of the transmission line can be accurately monitored. By using the mounting points and known reference planes to perform three-dimensional inversion of the transmission line, the accuracy of the transmission line sag calculation can be achieved to the decimeter level, which helps to improve the safety and stability of power facilities.

[0094] Next, a device for remotely sensing and monitoring the sag of a transmission line according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0095] Figure 7 Schematic diagram of a block diagram of a device for remotely sensing and monitoring transmission line sag according to an embodiment of the present application.

[0096] like Figure 7 As shown, the device 10 for remotely sensing and monitoring the sag of a transmission line includes: a determination module 100 , a correction module 200 and a calculation module 300 .

[0097] Among them, the determination module 100 is used to determine the positioning deviation of the synthetic aperture radar image based on the ground control point; the correction module 200 is used to correct the geometric positioning error of the synthetic aperture radar image based on the positioning deviation, determine the radar coordinate system coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid based on the corrected geometric positioning error, and extract the coordinates of the center point of the transmission line scattering spot; the calculation module 300 is used to construct the transmission line expression and elevation function in the radar coordinate system based on the radar coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid and the coordinates of the center point of the transmission line scattering spot, and calculate the sag state of the transmission line at the time of synthetic aperture radar image shooting based on the transmission line expression and elevation function.

[0098] In one embodiment of the present application, the determination module 100 is further used to obtain the actual measured geographic coordinates of the ground control point in the synthetic aperture radar image; use the geographic coordinates and the range Doppler equation to calculate the geometric positioning coordinates of the actual measured geographic coordinates of the ground control point in the radar coordinate system; determine the positioning deviation value of the synthetic aperture radar image based on the radar scattering imaging center point coordinates and the geometric positioning coordinates of the ground control point, wherein the radar scattering imaging center point coordinates of the ground control point are the coordinates of the scattering intensity extreme point within a preset range of the ground control point target, and the positioning deviation value of the radar image is used to correct the geometric positioning of the synthetic aperture radar image.

[0099] In one embodiment of the present application, the correction module 200 is further used to correct the geometric positioning error of the synthetic aperture radar image according to the positioning deviation, and solve the corresponding radar coordinate system coordinates through the range Doppler equation according to the geographical coordinates of the mounting points at both ends of the transmission line and the geographical coordinates of the projection points on the given reference ellipsoid, and extract the coordinates of the center point of the scattering spot of the transmission line.

[0100] In one embodiment of the present application, the calculation module 300 is further used to construct an expression and elevation function of the transmission line in the radar coordinate system based on the radar coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid, and the coordinates of the center point of the transmission line scattering spot. Based on the transmission line expression and elevation function, the range-Doppler equation is used to calculate the set of geographic coordinate points of the sag state of the transmission line at the time the synthetic aperture radar image is taken.

[0101] In one embodiment of the present application, the calculation module 300 is further used to obtain the coordinates of the center point of the scattering spot of the transmission line as the coordinates of the extreme point of the scattering intensity within a preset range of the scattering spot; using the radar coordinate system coordinates of the center point of the scattering spot of the transmission line and the mounting points at both ends of the line, under the condition that the tangent equation of the sag state function at the center point of the scattering spot is zero or there is an extreme value in the distance direction, obtain the transmission line expression of the transmission line in the radar coordinate system, and the transmission line expression is a parabolic equation or a hyperbolic equation.

[0102] In one embodiment of the present application, the calculation module 300 is further used to obtain the projection points of the mounting points at both ends of the transmission line on the ellipsoidal reference plane of a given elevation, and obtain the coordinates of the two projection points in the radar coordinate system through the range Doppler equation, and construct the equation of a straight line connecting the two projection points; solve the range deviation function between the straight line equation of the two projection points and the transmission line expression according to the azimuth direction, and obtain the incident angle and range resolution of the synthetic aperture radar image; determine the elevation function of the transmission line based on the range deviation function, the incident angle and the range resolution.

[0103] In one embodiment of the present application, the calculation module 300 is further used to solve the three-dimensional spatial sag state of the transmission line in the geographic coordinate system based on the transmission line expression, elevation function, range Doppler equation and ellipsoid equation; based on the three-dimensional spatial sag state of the transmission line in the geographic coordinate system and the local rectangular coordinate system conversion parameters, the sag state of the transmission line in the local rectangular coordinate system is obtained, and its maximum sag point and minimum sag value are calculated.

[0104] It should be noted that the above explanation of the embodiment of the method for remotely sensing the sag of a transmission line is also applicable to the device for remotely sensing the sag of a transmission line in this embodiment, and will not be repeated here.

[0105] According to the device for remote sensing monitoring of transmission line sag proposed in the embodiment of the present application, the changing sag state of the transmission line is monitored based on the synthetic aperture radar image of the transmission line, and the accuracy of transmission line sag calculation can be achieved to the decimeter level or even the centimeter level, which is helpful for the safe operation and maintenance status analysis and disaster warning assessment of overhead transmission line facilities.

[0106] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0107] A memory 801 , a processor 802 , and a computer program stored in the memory 801 and executable on the processor 802 .

[0108] When the processor 802 executes the program, the method for remotely sensing and monitoring the sag of a transmission line provided in the above embodiment is implemented.

[0109] Furthermore, the electronic device further includes:

[0110] The communication interface 803 is used for communication between the memory 801 and the processor 802 .

[0111] The memory 801 is used to store computer programs that can be run on the processor 802.

[0112] The memory 801 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0113] If the memory 801, the processor 802, and the communication interface 803 are implemented independently, the communication interface 803, the memory 801, and the processor 802 can be connected to each other via a bus and communicate with each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0114] Optionally, in a specific implementation, if the memory 801, the processor 802 and the communication interface 803 are integrated on a chip, the memory 801, the processor 802 and the communication interface 803 can communicate with each other through an internal interface.

[0115] The processor 802 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application.

[0116] The electronic device described in the embodiment of the present application can be placed on a SAR sensor platform to realize remote sensing data capture while carrying out edge computing, obtaining the sag state of the transmission line and performing status assessment and early warning. It can also be placed in a data processing center to analyze the sag state of the transmission line through the collected remote sensing data.

[0117] The present application also provides a computer-readable storage medium storing information such as a computer program, geographic coordinates of ground control points, and geographic coordinates of transmission line suspension points. When the computer program and the associated geographic coordinate data are executed by a processor, the aforementioned method for remotely sensing transmission line sag monitoring is implemented. The storage medium can be located on a SAR sensor platform or in a data processing center.

[0118] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0119] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0120] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0121] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0122] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0123] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for remotely sensing and monitoring the sag of a transmission line, characterized in that: The following steps are involved: Determine the positioning deviation of synthetic aperture radar images based on ground control points; Correcting the geometric positioning error of the synthetic aperture radar image according to the positioning deviation, determining the radar coordinates of the mounting points at both ends of the transmission line and their projections on a given reference ellipsoid according to the corrected geometric positioning error, and extracting the coordinates of the center point of the scattering spot of the transmission line; Constructing a transmission line expression and an elevation function in the radar coordinate system based on the radar coordinates of the mounting points at both ends of the transmission line and their projections on a given reference ellipsoid, and the coordinates of the center point of the scattering spot of the transmission line, and calculating the sag state of the transmission line at the time of synthetic aperture radar image capture based on the transmission line expression and the elevation function; The method comprises constructing a transmission line expression and an elevation function in a radar coordinate system based on the radar coordinates of the mounting points at both ends of the transmission line and their projections on a given reference ellipsoid, and the coordinates of the center point of the scattering spot of the transmission line, and calculating the sag state of the transmission line at the time of synthetic aperture radar image capture, including: obtaining a transmission line expression of the transmission line at the time of synthetic aperture radar image capture based on the coordinates of the center point of the scattering spot of the transmission line and the radar coordinate coordinates of the hanging points at both ends of the transmission line; A straight line equation is constructed based on the radar coordinate system coordinates of the projection points of the mounting points at both ends of the transmission line on the ellipsoid reference plane at a given elevation, and the elevation function of the transmission line is obtained by combining the transmission line expression. The sag function of the transmission line at the time of synthetic aperture radar image shooting in three-dimensional space is determined by the range Doppler equation based on the transmission line expression obtained at the time of synthetic aperture radar image shooting and the calculated elevation function of the transmission line.

2. The method for remote sensing monitoring of transmission line sag according to claim 1, characterized in that: Determining the positioning deviation of the synthetic aperture radar image according to the ground control point includes: Obtaining the actual measured geographic coordinates of the ground control points; Calculate the geometric positioning coordinates of the ground control point by converting the actual measured geographical coordinates into the radar coordinate system using the geographical coordinates and the range Doppler equation; The positioning deviation value of the synthetic aperture radar image is determined based on the radar scattering imaging center point coordinates of the ground control point and the geometric positioning coordinates, wherein the radar scattering imaging center point coordinates of the ground control point are the coordinates of the scattering intensity extreme point within a preset range of the ground control point target, and the positioning deviation value of the radar image is used to correct the geometric positioning of the synthetic aperture radar image.

3. The method for remote sensing monitoring of transmission line sag according to claim 1, characterized in that: The radar coordinates of the mounting points at both ends of the transmission line and their projection points on a given reference ellipsoid are determined based on the corrected geometric positioning parameters, including: Acquiring imaging parameters of the synthetic aperture radar image; Determining the coordinates of the mounting points at both ends of the transmission line according to the imaging parameters, the positioning deviation and the range Doppler model; Defining an ellipsoidal datum at a given elevation, wherein the given elevation is lower than the lowest point of suspension of the transmission line, and determining the geographic coordinates of corresponding projection points of the mounting points at both ends of the transmission line vertically projected onto the ellipsoidal datum at the given elevation; The radar coordinate system coordinates of the mounting points at both ends of the transmission line and the corresponding projection points of the mounting points at both ends projected onto the ellipsoid reference plane at the given elevation are determined according to the imaging parameters, the positioning deviation and the range Doppler model.

4. The method for remote sensing monitoring of transmission line sag according to claim 1, characterized in that: In the plane of the radar coordinate system, the transmission line expression of the transmission line at the time of synthetic aperture radar image capture is obtained based on the coordinates of the center point of the scattering spot of the transmission line and the radar coordinate system coordinates of the suspension points at both ends of the transmission line, including: Obtaining the coordinates of the center point of the scattering spot of the transmission line, where the coordinates of the center point of the scattering spot of the transmission line are the coordinates of the extreme value point of the scattering intensity within a preset range of the scattering spot; Using the radar coordinate system coordinates of the center point of the scattering spot of the transmission line and the mounting points at both ends of the line, and under the condition that the tangent equation of the sag state function at the center point of the scattering spot is zero or an extreme value exists in the distance direction, a transmission line expression of the transmission line in the radar coordinate system is obtained, and the transmission line expression is a parabolic equation or a hyperbolic equation.

5. The method for remote sensing monitoring of transmission line sag according to claim 1, characterized in that: The step of constructing a straight line equation based on the radar coordinate system coordinates of the projection points of the mounting points at both ends of the transmission line on the ellipsoid reference plane at a given elevation, and obtaining the elevation function of the transmission line in combination with the transmission line expression, includes: Obtaining the geographic coordinates of the projection points of the mounting points at both ends of the transmission line on an ellipsoidal reference plane at a given elevation, obtaining the coordinates of the two projection points in the radar coordinate system using the range-Doppler equation, and constructing the equation of a straight line connecting the two projection points; Solving the range deviation function between the straight line equation of the two projection points and the transmission line expression point by point along the azimuth direction, and obtaining the incident angle and range resolution parameters of the synthetic aperture radar image; An elevation function of the transmission line is determined based on the range deviation function, the incident angle, and the range resolution parameter.

6. The method for remote sensing monitoring of transmission line sag according to claim 1, characterized in that: Calculating the sag state of the transmission line at the time of synthetic aperture radar image capture according to the transmission line expression and the elevation function includes: Solving the three-dimensional sag state of the transmission line in the geographic coordinate system according to the transmission line expression, the elevation function, the range Doppler equation and the ellipsoid equation; According to the three-dimensional sag state of the transmission line in the geographic coordinate system and the conversion parameters of the local rectangular coordinate system, the sag state of the transmission line in the local rectangular coordinate system is obtained, and its maximum sag point and minimum sag point are calculated.

7. A device for remotely sensing and monitoring the sag of a transmission line, characterized in that: include: a determination module for determining the positioning deviation of the synthetic aperture radar image based on the ground control points; a correction module, configured to correct the geometric positioning error of the synthetic aperture radar image according to the positioning deviation, determine the radar coordinates of the mounting points at both ends of the transmission line and their projections on a given reference ellipsoid according to the corrected geometric positioning error, and extract the coordinates of the center point of the scattering spot of the transmission line; a calculation module, configured to construct an expression for the transmission line and an elevation function in the radar coordinate system based on the radar coordinates of the mounting points at both ends of the transmission line and their projections on a given reference ellipsoid, and the coordinates of the center point of the scattering spot of the transmission line, and calculate the sag state of the transmission line at the time of synthetic aperture radar image capture based on the expression for the transmission line and the elevation function; The calculation module is further configured to: obtain a transmission line expression of the transmission line at the time when the synthetic aperture radar image is captured based on the coordinates of the center point of the scattering spot of the transmission line and the radar coordinate system coordinates of the hanging points at both ends of the transmission line; construct a straight line equation based on the radar coordinate system coordinates of the projection points of the hanging points at both ends of the transmission line on an ellipsoid reference plane of a given elevation, and obtain the elevation function of the transmission line in combination with the transmission line expression; and determine the sag function of the transmission line at the time when the synthetic aperture radar image is captured in three-dimensional space using the range Doppler equation based on the transmission line expression obtained at the time when the synthetic aperture radar image is captured and the calculated elevation function of the transmission line.

8. An electronic device, characterized in that: include: 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 method for remotely sensing and monitoring the sag of a transmission line according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instruction is executed, the method for remotely sensing and monitoring the sag of a transmission line according to any one of claims 1 to 6 is implemented.

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