Railway line embankment settlement monitoring method and system based on space-borne InSAR remote sensing

Abstract

The application discloses a high-speed rail line roadbed settlement monitoring method based on a space-borne InSAR remote sensing, first, a wide range of settlement monitoring is carried out on a wide area along a high-speed rail line by using a space-borne InSAR technology, settlement information of the whole high-speed rail line roadbed is acquired, and a key area with a high settlement rate is identified; then, high-precision small-range observation is carried out on the key area by using an unmanned aerial vehicle-borne InSAR and LiDAR technology, and more detailed settlement data are acquired; then, long-term and regular key monitoring is carried out on the early warning area by using a ground monitoring device, and high precision and continuity of the settlement monitoring data are ensured; finally, the settlement monitoring result is displayed through a visual platform, and early warning information is sent to a high-speed rail operation monitoring center and related safety monitoring mechanisms in time. The application can monitor the settlement change of the high-speed rail line roadbed in a wide range and a long period, simultaneously improves the observation precision of the key monitoring area, and provides strong technical support for the safe operation of the high-speed rail line.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-speed railway line embankment settlement monitoring, and particularly relates to a high-speed railway line embankment settlement change monitoring method based on a space-borne InSAR (Interferometric Synthetic Aperture Radar) remote sensing technology, which can be widely applied to the fields of railway line embankment settlement monitoring, line maintenance and operation safety guarantee, etc. BACKGROUND

[0002] With the continuous expansion of the high-speed railway (high-speed rail) network, the stability and safety of high-speed railway lines have become one of the core problems to ensure the smooth operation of high-speed railways. The embankment settlement of high-speed railway lines is a key factor affecting the track structure and train operation safety. Track deformation caused by settlement may cause train operation instability, and even cause safety accidents. At present, the embankment settlement monitoring of high-speed railway lines mostly relies on traditional ground monitoring equipment such as settlement marks, total stations, GPS and levels, etc. However, these methods have limited monitoring accuracy, poor real-time performance, small spatial coverage, high labor cost and high labor intensity, etc. Especially in some complex terrain and harsh environment areas, it is difficult to efficiently and comprehensively monitor.

[0003] In addition, due to the large range of high-speed railway lines, which usually cross cities, mountains, rivers and other complex geographical environments, many areas have the characteristics of inconvenient transportation, difficult facility layout, extensive monitoring area, etc. It is particularly difficult to monitor comprehensively and accurately by traditional ground sensor layout. Moreover, the monitoring data are mostly point-like distribution, which makes it difficult to achieve timely, comprehensive and effective settlement monitoring of large-scale, long-line high-speed railway line embankment settlement in complex environments, and cannot reflect the dynamic changes of embankment settlement.

[0004] In recent years, with the continuous progress of remote sensing technology, especially the development of synthetic aperture radar (SAR) technology, space-borne InSAR (Interferometric Synthetic Aperture Radar) technology has gradually shown great potential in the field of ground settlement monitoring. InSAR technology uses satellite radar data for interferometric measurement, which can accurately obtain ground deformation information on a large scale and long time series basis, and has unique advantages such as all-weather, all-day, non-contact and wide coverage.

[0005] InSAR technology has been successfully applied in the field of large-scale infrastructure construction, such as urban land subsidence, landslide monitoring, dam deformation and other fields. For example, using PS-DInSAR (Permanent Scatterer Synthetic Aperture Radar Differential Interferometry) technology, researchers have successfully monitored land subsidence in many regions, especially in complex terrain and areas with frequent human activities. However, the existing InSAR technology still has certain limitations in the application of high-speed railway embankment settlement monitoring, mainly in the difficulty of meeting the high-precision and timeliness requirements of embankment settlement monitoring. Especially in the geological environment of frequent changes of high-speed railway lines and areas with poor transportation, how to realize high-precision and real-time monitoring of the settlement body is still a problem to be solved in current technology. SUMMARY

[0006] In order to solve the problems existing in the current high-speed railway embankment settlement monitoring method, the present application provides a kind of high-speed railway embankment settlement monitoring method based on space-borne InSAR remote sensing, which can realize large-scale, high-precision and high-timeliness high-speed railway embankment settlement monitoring, and provide real-time early warning and decision support for railway operation safety.

[0007] According to one aspect of the present application, a high-speed railway embankment settlement monitoring method based on space-borne InSAR remote sensing is provided, comprising:

[0008] Using space-borne InSAR technology to monitor the target high-speed railway line along the monitoring area, obtaining InSAR image data of the monitoring area;

[0009] Dividing the monitoring area along the target high-speed railway line into sections, combining the InSAR image data to obtain the settlement state of each section, and then screening out potential abnormal sections with continuous settlement trend and dynamic amplification;

[0010] Implementing unmanned aerial vehicle carrying InSAR and LiDAR sensing system monitoring on the screened potential abnormal sections, and performing risk evolution analysis based on the monitoring data to determine the settlement warning area;

[0011] Setting up several ground monitoring points in the determined settlement warning area to perform real-time deformation monitoring.

[0012] As a further technical solution, obtaining InSAR image data of the monitoring area further comprises:

[0013] Selecting multi-orbit, multi-temporal SAR satellite image data covering the entire monitoring area of the target high-speed railway line to obtain long-time sequence deformation information of the monitoring area, wherein the monitoring area is the sensitive zone of the main line of the target high-speed railway line and the range set on both sides.

[0014] As a further technical solution, the monitoring area is divided into sections along the target high-speed rail line, and the settlement state of each section is obtained by combining InSAR image data, which also includes:

[0015] The monitoring area is divided into several small range sections according to the actual line state, and the SAR image data obtained is registered, interferogram generated, phase unwrapping and time series inversion processing by using multi-temporal satellite InSAR interferogram and least squares time series processing method, to obtain the deformation rate and time series settlement covering the entire monitoring area, so as to obtain the settlement state of each section.

[0016] As a further technical solution, the potential abnormal section with continuous settlement trend and dynamic amplification is screened out, which also includes:

[0017] According to the monitoring of the expected target, double thresholds are set: average annual settlement rate > T1 and rate change rate > T2;

[0018] The spatial distribution and evolution trend of the settlement rate abnormal point are analyzed, and the potential abnormal section with continuous settlement trend and dynamic amplification is screened out according to the set double thresholds, as the next step of detection object.

[0019] As a further technical solution, the potential abnormal section screened out is monitored by unmanned aerial vehicle carrying InSAR and LiDAR sensing system, and risk evolution analysis is carried out based on the monitoring data, which also includes:

[0020] According to the terrain point cloud obtained by airborne LiDAR, digital elevation model refinement processing is carried out to enhance the phase unwrapping accuracy of InSAR image data;

[0021] According to the terrain point cloud obtained by airborne LiDAR, digital surface model and building / vegetation shielding information are generated to provide prior model for InSAR interference centering process;

[0022] The obtained InSAR image data is registered, interferogram generated, phase unwrapping and time series inversion processing, to obtain InSAR deformation time series data;

[0023] The obtained InSAR deformation time series data is input into the time series analysis module for risk evolution analysis to evaluate the local maximum settlement rate and settlement acceleration, and the maximum settlement risk section in the section is set as the settlement warning area.

[0024] As a further technical solution, the time series analysis module adopts Kalman filter or Bayesian variable point detection algorithm.

[0025] As a further technical solution, the method further includes:

[0026] The obtained subsidence data of InSAR large-scale monitoring is fused with the GIS data of the target high-speed rail line, and the spatial distribution, development trend of the subsidence and the potential influence on the track safety are analyzed by combining the GIS data, meteorological data and historical subsidence records.

[0027] As a further technical solution, the method further comprises:

[0028] The monitored subsidence data is converted into a three-dimensional visualization model, and the dynamic change process of the subsidence is displayed in combination with a time axis.

[0029] As a further technical solution, when a plurality of ground monitoring points are arranged in the determined subsidence warning area:

[0030] The ground monitoring equipment used includes but is not limited to a total station, a ground-based synthetic aperture radar, a GNSS receiving device, a digital level and a ground surface crack monitoring sensor.

[0031] According to an aspect of the present application, a high-speed rail line embankment subsidence monitoring system based on spaceborne InSAR remote sensing is provided, comprising:

[0032] The spaceborne InSAR device is used for obtaining a large-scale background deformation field and preliminarily screening an abnormal section.

[0033] The unmanned aerial vehicle carries InSAR and LiDAR sensing devices, which are used for mesoscale high-resolution three-dimensional reconstruction and deformation refinement identification.

[0034] The ground fixed monitoring device is arranged in a high-risk or key structure area and is used for high-frequency and long-term deformation monitoring.

[0035] Compared with the prior art, the present application has the following beneficial effects:

[0036] The high-speed rail line embankment subsidence monitoring method based on spaceborne InSAR remote sensing provided by the present application can be implemented on a large range of high-speed rail lines. First, the subsidence of the entire line is monitored by using spaceborne InSAR, then high-precision observation of unmanned aerial vehicle-borne InSAR and LiDAR is carried out for the area with a large subsidence rate, and finally ground monitoring equipment is arranged at the observation points in the key monitoring area for detailed subsidence change monitoring. Through the multi-dimensional collaborative monitoring mode, accurate subsidence data can be provided to help management personnel realize efficient decision support.

[0037] The application can help high-speed rail operation managers to find potential settlement risks in time, avoid serious influence of foundation settlement on the track, ensure train operation safety, and reduce disaster losses by combining GIS data and three-dimensional visual display. The method can not only realize long-term monitoring of high-speed rail lines, but also provide important data support for subsequent high-speed rail construction and maintenance. The application of InSAR technology in the transportation industry is of great significance, and has important economic and social benefits. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0039] Figure 1 A flowchart of a high-speed rail line subgrade settlement monitoring method based on satellite-borne InSAR remote sensing provided by the embodiment of the present application is shown.

[0040] Figure 2 A principle diagram of a high-speed rail line subgrade settlement monitoring method based on satellite-borne InSAR remote sensing provided by the embodiment of the present application is shown.

[0041] In the figure: 1-satellite-borne InSAR, 2-unmanned aerial InSAR and LiDAR, and 3-ground monitoring equipment. DETAILED DESCRIPTION

[0042] In view of the fact that the prior art cannot meet the high-precision and high-timeliness subgrade settlement monitoring, especially the monitoring problems in the frequently changing geological environment of high-speed rail lines and the areas with inconvenient transportation, the present application provides a high-speed rail line subgrade settlement monitoring method based on satellite-borne InSAR remote sensing. The method can not only realize all-weather, large-range, non-contact monitoring of a wide area, but also meet the monitoring needs of high-speed rail line safe operation in terms of high precision and timeliness, and has important practical significance for improving the operation safety of high-speed rail lines and early warning of settlement risks.

[0043] The overall technical concept of the present application is that satellite-borne InSAR technology, unmanned aerial InSAR and LiDAR technology, and ground monitoring equipment are used to perform multi-dimensional collaborative monitoring on the subgrade along the high-speed rail line, and the monitoring results are displayed through three-dimensional visualization technology, so as to help managers to quickly and intuitively master the settlement information of a large range of lines and make decisions in time.

[0044] Specifically, the multi-dimensional cooperative monitoring includes: firstly, using the spaceborne InSAR technology to carry out large-range settlement monitoring along the target high-speed rail line, and screening out key areas with high settlement rates; then, using the unmanned aerial InSAR and LiDAR technology to carry out high-precision small-range observation on the key areas, and screening out early warning areas; and then, using the ground monitoring equipment to carry out periodic and long-term key monitoring on the early warning areas, and obtaining real-time data of settlement changes.

[0045] The large-range settlement monitoring of the high-speed rail line using the spaceborne InSAR technology refers to: firstly, combining the high-speed rail line infrastructure data, geographic information and meteorological data to pre-process the spaceborne InSAR data; and then, carrying out inversion analysis on the settlement information obtained by the spaceborne InSAR, and obtaining the settlement size, rate and distribution of the entire line.

[0046] The observation on the key areas using the unmanned aerial InSAR and LiDAR technology refers to: according to the monitoring results of the spaceborne InSAR, selecting areas with high settlement rates or potential safety hazards, and using the unmanned aerial InSAR and LiDAR to carry out high-precision and local-range observation, and further obtaining detailed roadbed settlement and surrounding environment change data.

[0047] The ground monitoring equipment includes a ground-based SAR, a total station, a GPS and the like, and is used for long-term and fixed-point observation on the early warning areas, real-time acquisition of settlement change data, and ensuring the accuracy and continuity of the monitoring data.

[0048] The intuitive display of the monitoring results in a three-dimensional visualization manner refers to: combining the data collected from the spaceborne InSAR, the unmanned aerial InSAR and the LiDAR, and the ground monitoring equipment, generating a three-dimensional settlement monitoring model, and displaying the settlement change process according to a time axis, and helping the management personnel to clearly and intuitively understand the settlement dynamics.

[0049] The early warning information is transmitted to the high-speed rail operation monitoring center and the related safety monitoring mechanism through an application program, so as to realize rapid transmission and emergency response of the information.

[0050] The application also combines the geographic information system (GIS) data of the high-speed rail line for comprehensive analysis: fusing the settlement data obtained by the InSAR monitoring and the GIS data of the high-speed rail line, combining the geographic information, meteorological data and historical settlement records, and analyzing the spatial distribution, development trend and potential influence on the track safety of the settlement.

[0051] For long time series of subsidence data obtained by space-borne InSAR technology, through spatial registration and fusion processing with GIS data of target high-speed rail line, further combined with regional meteorological data (such as precipitation, groundwater level change, ground temperature, etc.) and existing historical subsidence records, the spatial distribution characteristics, time evolution trend of subsidence and its potential impact on the safety of track structure are comprehensively analyzed.

[0052] Specifically includes the following steps: the subsidence rate map and the subsidence time series map obtained by InSAR inversion are spatially aligned with the high-speed rail line GIS vector data (including line center line, track mileage, structure position, etc.) based on a unified coordinate system (such as WGS84 or Gauss-Kruger projection), so that all kinds of data have consistent spatial reference system. According to the high-speed main line center line, buffer zones such as 20m, 50m, 100m are constructed, and the line is divided into several monitoring sections according to the section length (such as every 500m or every structure unit). The average, maximum and standard deviation of the subsidence rate corresponding to the InSAR data in each section are counted. The historical subsidence event database (such as the record of track disease treatment in previous years) is matched with the current InSAR subsidence hotspot area in position to determine whether the anomaly is repeated. At the same time, the regional meteorological data (precipitation, temperature, groundwater level) are inputted, and the correlation analysis, grey correlation analysis or multivariate linear regression method is used to quantify the influence of natural environmental factors on the subsidence trend.

[0053] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application. In addition, the technical features in each embodiment or single embodiment provided by the present application can be combined with each other to form new technical scheme, and the combination is not restricted by the order of steps and / or structure composition mode, but should be based on the realization by those skilled in the art, when the combination of technical scheme appears contradictory or cannot be realized, it should be considered that the combination of technical scheme does not exist, and is not within the protection scope required by the present application.

[0054] This invention discloses a method for monitoring subgrade settlement of high-speed railway lines based on spaceborne InSAR remote sensing. First, spaceborne InSAR technology is used to conduct long-distance, large-scale deformation monitoring of the monitoring area along the target high-speed railway line, acquiring InSAR image data of the monitoring area. Next, the monitoring area is divided into sections along the target high-speed railway line, and the settlement status of each section is obtained by combining the InSAR image data, thereby screening out potential abnormal sections with continuous settlement trends and dynamic amplification. Subsequently, the screened potential abnormal sections are monitored using UAVs equipped with InSAR and LiDAR sensing systems, and risk evolution analysis is performed based on the monitoring data to determine settlement warning areas. Finally, several ground monitoring points are set up in the determined settlement warning areas to perform real-time deformation monitoring.

[0055] like Figure 1 As shown, the method of the present invention specifically includes the following steps:

[0056] First, spaceborne synthetic aperture radar interferometry (InSAR) technology is used to conduct long-distance, large-scale deformation monitoring of a wide area along the target high-speed railway line.

[0057] Specifically, multi-orbit, multi-temporal SAR satellite imagery data covering the entire route and a certain buffer zone around it are selected to obtain long-term deformation information of the target areas, including roadbed, bridges, tunnel entrances, and soft soil sections. For example... Figure 2 As shown, AA' represents the overall observation range covered by the monitoring during this stage, including the main line of the high-speed railway and a certain range of sensitive areas on both sides. The acquired monitoring data has the characteristics of strong spatial continuity, long time span, and short observation period, making it suitable for identifying long-term settlement trends of high-speed railway subgrade and initial screening of abnormal sections.

[0058] Next, the overall observation range (i.e., the monitoring area) is divided into n smaller segments a1...a2 based on the actual line conditions. n Using multi-temporal spaceborne InSAR interferometric images, least squares time-series processing methods (such as SBAS-InSAR and PS-InSAR) were employed to register, generate interferograms, unwrap phases, and perform time-series inversion processing on the acquired SAR image data. This yielded deformation rates and time-series subsidence covering the entire monitoring area, thus obtaining the subsidence status of each segment. Based on the expected monitoring targets, dual thresholds were set: average annual subsidence rate > T1 (e.g., 5 mm / year) and rate of change (acceleration) > T2 (e.g., 2 mm / year²). By analyzing the spatial distribution and evolution trend of subsidence rate anomalies, potential anomaly segments with continuous subsidence trends and dynamic amplification were screened and marked as preliminary key monitoring areas. i As the next detection target, corresponding to... Figure 2B1B1', B2B2' shown in FIG. 1.

[0059] Then, the key section screened out is monitored by a high-resolution InSAR carried by a drone, and a DEM (digital elevation model) is refined by combining the terrain point cloud obtained by the LiDAR, so as to enhance the phase unwrapping precision. The LiDAR data is used to generate a higher-precision DSM (digital surface model) and building / vegetation shielding information, to provide a high-quality prior model for the InSAR interference process, and significantly reduce noise interference. The obtained InSAR deformation time series data is input into a time series analysis module (such as a Kalman filter or a Bayesian Change Point Detection algorithm) for risk evolution analysis, so as to evaluate the local maximum settlement rate and settlement acceleration, clarify the settlement development trend, and set the maximum settlement risk section in the section as a warning area, such as Figure 2 The section corresponding to C1C1', C2C2' shown in FIG. 1.

[0060] Finally, a plurality of ground monitoring points are further arranged in the settlement warning area, such as Figure 2 The observation points E1, E2 shown in FIG. 1 are used to carry out higher-precision and more real-time deformation monitoring. The above monitoring points are mainly arranged in structural sensitive sections, such as bridges, culverts, tunnel entrances and exits, soft foundation sections and other key parts prone to settlement or uneven deformation. The ground monitoring equipment used can include but is not limited to a total station, a ground-based synthetic aperture radar (GBSAR), a GNSS receiving device, a digital level and a ground surface crack monitoring sensor, etc. Among them, the total station and the GNSS receiving device are mainly used to provide high-precision three-dimensional displacement data, the GBSAR can realize large-area continuous monitoring without physical contact, has the ability to work all-weather, and is suitable for dynamic settlement evaluation of structural members such as bridge piers and abutments. The ground monitoring data is subjected to time series analysis by a data processing module (which can combine polynomial fitting, Kalman filter or deformation rate fitting algorithms), to form a long-term continuous settlement change curve, cross-verify with the previous InSAR and LiDAR detection results, supplement high-precision data and effectively identify data anomalies, and further improve the settlement rate prediction precision and warning sensitivity.

[0061] In the implementation process, the application adopts three types of cooperative equipment systems: equipment 1 is a spaceborne InSAR system, which is used for obtaining a large-scale background deformation field and preliminarily screening an abnormal section; equipment 2 is an unmanned aerial vehicle (UAV) carrying an InSAR and LiDAR sensing system, which is used for medium-scale high-resolution three-dimensional reconstruction and deformation refinement identification; and equipment 3 is a ground fixed monitoring device, which is mainly deployed in a high-risk or key structure area and is responsible for carrying out high-frequency and long-term deformation monitoring work. The three types of equipment form an air-ground integrated hierarchical monitoring system, in which the ground monitoring equipment undertakes the role of confirming a subsidence trend and supplementing local details in the application, and provides key timing support data for finally forming a subsidence warning model.

[0062] The high-speed rail line embankment subsidence monitoring method based on spaceborne InSAR remote sensing provided by the application can realize full-range, real-time and accurate monitoring of high-speed rail line embankment subsidence under complex environments through satellite remote sensing monitoring, and can effectively avoid safety hazards caused by subsidence problems. The method not only can monitor embankment subsidence in a large range and for a long time, but also can perform high-precision observation in key areas, effectively improves the monitoring accuracy and response timeliness, and provides reliable protection for high-speed rail operation safety.

[0063] Based on the same inventive concept as the foregoing embodiments, the application embodiment also provides a high-speed rail line embankment subsidence monitoring system based on spaceborne InSAR remote sensing, as shown in Figure 2 , first, the spaceborne InSAR equipment is used to monitor the subsidence of the entire line (such as the AA' area in Figure 2 ), then the unmanned aerial vehicle (UAV) InSAR and LiDAR equipment are used for high-precision observation of the area with a high subsidence rate (such as the B1B1', B2B2' part in Figure 2 ), and finally the ground monitoring equipment is deployed at the observation points (such as E1 and E2 in Figure 2 ) in the key monitoring area (such as the C1C1', C2C2' part in Figure 2 ) to perform detailed subsidence change monitoring. Through the multi-dimensional cooperative monitoring mode, accurate subsidence data can be provided to help management personnel achieve efficient decision support.

[0064] The implementation steps of the system are specifically described as follows:

[0065] First, the spaceborne InSAR equipment is used to monitor the large-scale subsidence of the target high-speed rail line embankment to obtain the ground deformation information along the line. The spaceborne InSAR equipment can perform high-precision interferometric measurement on the ground through satellite radar, and can cover a wide area of various terrains such as cities and mountainous areas. By analyzing the InSAR data of the overall observation line AA' area, the sections with a high subsidence rate are identified through segmented calculation, such as the a i , as shown in Figure 2B1B1' and B2B2' in FIG. 1B, and mark these areas as the objects of subsequent intensive monitoring.

[0066] For the intensive areas found in the satellite-borne InSAR device monitoring, further high-precision local observation is carried out using unmanned aerial InSAR and LiDAR devices. The unmanned aerial vehicle can enter the area with high precision requirements and use high-resolution radar images for detailed monitoring. The technical advantage of unmanned aerial InSAR and LiDAR devices lies in the ability to provide small-range, high-precision data collection, especially in some difficult-to-access areas (such as mountainous areas, near bridges, or complex urban environments), providing key subsidence dynamic data. The observation range of this part is shown in B1B1' and B2B2' in FIG. 1B. Figure 2

[0067] In the early warning area, intensive subsidence monitoring is carried out in combination with ground monitoring devices 3 (such as total station, ground-based SAR, GPS, etc.), to ensure the continuity and accuracy of the monitoring data. Ground-based devices are mainly used to obtain high-precision subsidence change data in real time and can provide rapid response in a short time. Near high-risk areas, install ground-based SAR, total station, and other ground monitoring devices 3 for all-weather, long-time sequential point observation to achieve continuous tracking and verification of subsidence. The observation points of this part are shown as E1 and E2 in FIG. 1C. Figure 2

[0068] Fuse and analyze the data collected by the satellite-borne InSAR device, unmanned aerial InSAR and LiDAR device, and ground monitoring device to generate subsidence monitoring results. Through geographic information system (GIS) and three-dimensional visualization technology, the subsidence data is intuitively displayed to the management personnel. Management personnel can view the subsidence changes of high-speed rail embankment in real time through three-dimensional models, and analyze the dynamic process of subsidence according to the time axis, so as to make scientific decisions quickly.

[0069] For the subsidence abnormal areas found, the system will automatically generate early warning information and send it to the high-speed rail operation monitoring center and relevant safety monitoring agencies through the application. In this way, the relevant monitoring center or agency can intervene and adjust in time to avoid further subsidence and cause safety hazards.

[0070] ​​In summary, the application discloses a high-speed rail line embankment settlement monitoring method based on a satellite-borne InSAR remote sensing, which first uses the satellite-borne InSAR technology to monitor the settlement of a wide area along the high-speed rail line, obtains the settlement information of the entire high-speed rail line embankment, and identifies the key area with a high settlement rate; then uses the unmanned aerial InSAR and LiDAR technologies to perform high-precision small-range observation on the key area, and obtains more detailed settlement data; then uses the ground monitoring equipment (such as a ground-based SAR, a total station, etc.) to perform long-term and regular monitoring on the warning area, and ensures the high precision and continuity of the settlement monitoring data; finally, the settlement monitoring result is displayed through a visual platform, and the warning information is sent to the high-speed rail operation monitoring center and the related safety monitoring mechanism in time, to help the management personnel make quick decisions and emergency responses. The technology can monitor the settlement change of the high-speed rail line embankment in a wide range and a long period, improves the observation precision of the key monitoring area, and provides strong technical support for the safe operation of the high-speed rail line.

[0071] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the application.

Claims

1. A high-speed rail line embankment settlement monitoring method based on spaceborne InSAR remote sensing, characterized in that, The method comprises the following steps: Monitoring the target high-speed rail line along the monitoring area by using the spaceborne InSAR technology to obtain InSAR image data of the monitoring area; Dividing the monitoring area into sections along the target high-speed rail line, obtaining the settlement state of each section by combining the InSAR image data, and then screening out potential abnormal sections with a continuous settlement trend and dynamic amplification, including: dividing the monitoring area into small range sections according to the actual line state, using multi-temporal spaceborne InSAR interferometric images, and using the least square time series processing method to perform registration, interferogram generation, phase unwrapping and time series inversion processing on the obtained SAR image data to obtain the deformation rate and time series settlement covering the entire monitoring area, thereby obtaining the settlement state of each section; further including: setting double thresholds according to the monitoring target: average annual settlement rate > T1 and rate change rate > T2; analyzing the spatial distribution and evolution trend of the settlement rate abnormal points, screening out potential abnormal sections with a continuous settlement trend and dynamic amplification according to the set double thresholds, and taking them as the next detection objects; Implementing unmanned aerial vehicle-mounted InSAR and LiDAR sensor system monitoring on the screened potential abnormal sections, and determining the settlement warning area based on the monitoring data; Setting a plurality of ground monitoring points in the determined settlement warning area to perform real-time deformation monitoring.

2. The method according to claim 1, wherein, Obtaining the InSAR image data of the monitoring area further comprises: Selecting multi-orbit, multi-temporal SAR satellite image data covering the entire monitoring area of the target high-speed rail line to obtain long time series deformation information of the monitoring area, wherein the monitoring area is a sensitive zone set on the main line of the target high-speed rail line and the range on both sides thereof.

3. The method according to claim 1, wherein, Implementing unmanned aerial vehicle-mounted InSAR and LiDAR sensor system monitoring on the screened potential abnormal sections, and performing risk evolution analysis based on the monitoring data, further comprising: Performing digital elevation model refinement processing on the terrain point cloud obtained by the airborne LiDAR to enhance the phase unwrapping accuracy of the InSAR image data; Generating a digital surface model and building / vegetation shielding information from the terrain point cloud obtained by the airborne LiDAR to provide a prior model for the InSAR interference centering process; Performing registration, interferogram generation, phase unwrapping and time series inversion processing on the obtained InSAR image data to obtain InSAR deformation time series data; The obtained InSAR deformation time series data is input into a time series analysis module for risk evolution analysis to evaluate the local maximum settlement rate and settlement acceleration, and the section with the maximum settlement risk is set as the settlement warning area.

4. The method according to claim 3, wherein, The time series analysis module is implemented by using a Kalman filter or a Bayesian variable point detection algorithm.

5. The method according to claim 1, wherein, The method further comprises: Fusing the settlement data obtained by the InSAR large-scale monitoring with the GIS data of the target high-speed rail line, combining the GIS data, meteorological data and historical settlement records to analyze the spatial distribution, development trend of the settlement and the potential impact on the track safety.

6. The method according to claim 1, wherein, The method further comprises: The monitored subsidence data is converted into a three-dimensional visualization model, and the dynamic change process of subsidence is shown in combination with a time axis.

7. The method according to claim 1, wherein, When setting a number of ground monitoring points in a determined subsidence early warning area: The ground monitoring equipment used includes but is not limited to a total station, a ground-based synthetic aperture radar, a GNSS receiving device, a digital level and a ground surface crack monitoring sensor.

8. A high-speed railway line embankment settlement monitoring system based on spaceborne InSAR remote sensing, characterized in that, It comprises: A space-borne InSAR device is used to obtain a large-scale background deformation field and preliminarily screen abnormal sections, and comprises: dividing a monitoring area into a plurality of small-scale sections according to an actual line state, using multi-temporal space-borne InSAR interferometric images, adopting a least square time series processing method to perform registration, interferogram generation, phase unwrapping and time series inversion processing on obtained SAR image data, obtaining a deformation rate and a time series subsidence covering the entire monitoring area, and thus obtaining a subsidence state of each section; further comprising: setting double thresholds according to a monitoring expected target: an average annual subsidence rate > T1 and a rate change rate > T2; analyzing a spatial distribution and an evolution trend of subsidence rate abnormal points, screening out potential abnormal sections with a continuous subsidence trend and a dynamic amplification as a next detection object according to the set double thresholds; An unmanned aerial vehicle is used to carry an InSAR and a LiDAR sensing device to obtain a mesoscale high-resolution three-dimensional reconstruction and deformation refinement identification; Ground fixed monitoring equipment is deployed in a high-risk or key structure area to perform high-frequency and long-term deformation monitoring.

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