Mountain area expressway geological line selection method based on time sequence InSAR technology

Abstract

The invention provides a mountain area highway geological line selection method based on a time sequence InSAR technology, and belongs to the technical field of road engineering, and the method comprises the following steps: S1, preparing before geological line selection, and collecting highway information data; s2, processing and analyzing InSAR data, and performing processing and deformation measurement on the InSAR data by using professional software; s3, geological line selection field work is carried out, and geological information and data in a route corridor zone are acquired by adopting geological plotting; s4, geological line selection interior work is carried out, unfavorable geologic characteristic distribution diagrams, tables and text reports in the corridor zone are formed, unfavorable geologic susceptible area diagrams are divided, route schemes and structure setting suggestions are provided for the proposed expressway, and geological line selection results are formed; s5, geological line selection effect analysis is carried out, and earth surface deformation monitoring is carried out along the highway construction and operation stage; and S6, ending the service life cycle of the expressway, and ending the geological line selection. The problems of precision, accuracy, breadth and reliability of geological line selection are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of road engineering, and in particular relates to a geological route selection method for mountain highways based on time-series InSAR technology. Background Art

[0002] Geological route selection is an important method, means and purpose for highway route selection. Compared with plain or hilly areas, mountain highway construction has higher requirements for geological route selection. At present, the defects and shortcomings of geological route selection for mountain highways are mainly reflected in the following aspects:

[0003] (1) The geological route selection ideas, experience and methods used in plain or hilly areas are often used to passively serve the highway route design and can no longer meet the actual needs of highway construction in mountainous areas.

[0004] (2) At present, the means of geological line selection are limited to geological survey, geophysical exploration and drilling within the ground range, which are relatively simple, narrow in vision, low in precision and efficiency, and the results of geological line selection are more qualitative than quantitative;

[0005] (3) In the process of geological route selection for mountain highways, various types of adverse geology (landslides, collapse accumulations and unstable slopes) encountered have complex boundaries and large development scales. Existing route selection methods cannot accurately identify them, and there is a risk of omission;

[0006] (4) The displacement and deformation of each unfavorable geological body is timely and long-term. At present, the geological line selection method is based on the current and discontinuous understanding of the displacement and deformation characteristics of each unfavorable geological body. There is a lack of continuous historical data, so the understanding is one-sided;

[0007] (5) Highway geological route selection should be integrated into the entire life cycle of highway design, construction and operation. However, it is currently only an idea and concept, mainly applicable to the highway design stage, and there is no unified and specific method and procedure guarantee system, so it is not very operational. Summary of the invention

[0008] The embodiment of the present invention provides a method for geological route selection of mountain highways based on time-series InSAR technology, which solves the problems of precision, accuracy, breadth and reliability of geological route selection.

[0009] In view of the above problems, the technical solution proposed by the present invention is:

[0010] The present invention provides a method for geological route selection of mountain highways based on time-series InSAR technology, comprising the following steps:

[0011] S1, the preparation work before geological route selection is to collect relevant information data along the proposed expressway. Among them, radar satellites should be selected for InSAR data acquisition to obtain image data with high resolution and short revisit period;

[0012] S2, InSAR data processing and analysis, using professional processing software to process InSAR data and measure deformation;

[0013] S3, geological route selection field work, using geological survey, geophysical exploration and drilling to obtain geological information and data of InSAR deformation areas within the route corridor;

[0014] S4, internal work of geological line selection, using geotechnical software to establish a geological model of the deformation zone, perform stability calculation and analysis, analyze and determine the deformation cause and trend of the deformation zone, and form a distribution map, table and text report of adverse geological characteristics in the corridor on the basis of the work in steps S2 and S3, divide the map of areas prone to adverse geological conditions, propose route plans and structure settings for the proposed expressway, and form geological line selection results;

[0015] S5, geological route selection effect analysis, monitoring of surface deformation along the expressway during construction and operation, guiding construction and operation maintenance, technical summary of geological route selection results, and forming a geological route selection case database;

[0016] S6, the life cycle of the expressway ends and the geological route selection ends;

[0017] The step S4 performs a spatial analysis function based on the information volume method. The specific steps of the information volume method are as follows:

[0018] S41, the information volume model extracts the distribution of geological disaster points in the area where geological disasters have occurred, selects a certain number of factors, and converts the measured data of the study area into quantifiable information volume values, which are used as quantitative indicators to measure the susceptibility of geological disasters. The information volume value is expressed by the formula:

[0019]

[0020] Among them, I ij is the information value of the jth category of the ith evaluation factor, N ij is the number of geological disasters of the jth type in the ith evaluation factor, N is the total number of geological disasters in the study area, S ij is the number of grid cells of the jth category with the ith evaluation factor, S is the total number of evaluation units in the study area, and after determining the total number of evaluation factors n, the total information value I of the evaluation unit is calculated by the following formula:

[0021]

[0022] The total information value I is used to determine the susceptibility level of the study unit. The larger the comprehensive information value of each evaluation index in the unit, the more favorable it is for the occurrence of geological disasters, and the higher its susceptibility level. The information amount is superimposed on each unit in the study area, and the units are divided into different levels of prone areas according to the size of the comprehensive information amount.

[0023] As a preferred technical solution of the present invention, the highway information data in step S1 includes the highway project proposal, engineering feasibility study report, topographic map of the proposed highway corridor, regional geological data, geological disaster prevention and control plan and geological disaster investigation and design documents.

[0024] As a preferred technical solution of the present invention, the specific steps of step S2 are as follows:

[0025] S21, satellite selection and data collection, select the appropriate radar satellite;

[0026] S22, extracting high-quality InSAR data at multiple time points, obtaining high-quality InSAR data at multiple time points, including two radar images acquired at different times by interferometry;

[0027] S23, image registration and correction, interferometric image registration, registration of the interferometric pair, including phase correction, geometric correction and atmospheric correction of the interferometric pair;

[0028] S24, filtering and noise processing, filtering the phase, removing noise and unstable signals, performing multi-time superposition, combining deformation graphs at multiple times, and obtaining deformation results;

[0029] S25, Verification, Ground Verification Use ground-based data to verify the InSAR results and perform time series analysis to track the evolution of surface deformation and identify seasonal and long-term deformation trends.

[0030] As a preferred technical solution of the present invention, the phase correction in step S23 is to use the phase information of the two images to perform phase analysis to obtain a phase difference map. The specific steps are as follows:

[0031] S231, remove the flat earth phase, simulate the flat earth model using DEM and subtract it from the interferogram to remove it;

[0032] S232, terrain phase correction, uses DEM to simulate the phase change caused by terrain and subtracts it from the interferogram to eliminate the influence of terrain on the phase;

[0033] S233, Phase Filtering, applies filtering techniques to reduce noise and outliers.

[0034] As a preferred technical solution of the present invention, the geometric correction in step S23 uses a phase difference map to calculate the deformation of the surface in the direction of the radar line of sight. The deformation amount is usually calculated by differential measurement, that is, the phase difference between two time points. The calculation steps of the deformation amount are as follows:

[0035] A, interferometric pair selection, selecting two InSAR images with similar time points as interferometric pairs;

[0036] B, Interference pattern generation, register the two InSAR images to generate the interference pattern;

[0037] C, geometric correction, converts the interferogram in the radar coordinate system to the geographic coordinate system and adjusts the size and shape of the pixels to correspond to the surface features;

[0038] D, deformation calculation, the deformation of the surface in the direction of the radar line of sight (ΔR) is calculated by the following formula:

[0039]

[0040] Among them, λ is the wavelength of the radar wave, Δφ is the phase difference between two time points, B is the baseline length (along the track direction), B⊥ is the vertical component of the baseline, and θ is the incident angle of the radar wave.

[0041] As a preferred technical solution of the present invention, the specific steps of the atmospheric correction in step S23 are as follows:

[0042] a. Use the atmospheric model to calculate the effect of the atmosphere on radar wave propagation and make corrections;

[0043] b. Using SAR data of different frequencies to separate the effects of atmospheric and non-atmospheric factors;

[0044] d. Identify and remove atmospheric noise by analyzing interference pairs at multiple time points and spatial locations.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] (1) The present invention utilizes InSAR technology to strengthen the existing means of geological route selection. By monitoring and analyzing the surface deformation of the proposed mountain highway corridor, the dimension, breadth, accuracy and precision of the geological route selection are increased, thereby improving the reliability and efficiency of the geological route selection.

[0047] (2) Based on the information quantity method, the present invention converts the measured data of each object element of geological line selection into a quantifiable information quantity value, which is used as a quantitative indicator to measure the susceptibility of adverse geological conditions. Combined with the adverse geological development of the proposed expressway in the mountainous area, based on the information quantity results, the density of adverse geological points or surface density is considered as an auxiliary basis, and the susceptibility is divided into high and low levels, which becomes the main achievement of geological line selection.

[0048] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a flow chart of a method for geological route selection of mountain highways based on time-series InSAR technology disclosed in the present invention;

[0050] Figure 2 It is a flow chart of step S2 of a method for geological route selection of mountain highways based on time-series InSAR technology disclosed in the present invention. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0054] Embodiment 1

[0055] See attached Figure 1-2As shown, the present invention provides a technical solution: a method for geological route selection of mountain highways based on time-series InSAR technology, comprising the following steps:

[0056] S1. Preparation work before geological line selection. Collect highway information data including highway project proposal, engineering feasibility study report, topographic map of the proposed highway corridor, regional geological data, geological disaster prevention and control plan and geological disaster survey and design documents. For InSAR data acquisition, radar satellites should be selected, such as TerraSAR-X, COSMO-SkyMed, SentInel-1, etc. Satellites provide high-resolution and short revisit period InSAR data, which are divided into free or paid. For example, SentInel satellite is the first satellite developed by Copernicus Global Earth Observation Project, which belongs to European Space Agency. SentInel-1 satellite uses C band as operating band, which has the advantages of all-day, all-weather, dual polarization and short revisit period. Its orbit altitude is about 700km, and the revisit period can reach 12 days.

[0057] S2, InSAR data processing and analysis, using professional processing software to process InSAR data, such as StaMPS, GMTSAR, SNAPHU, SARscape, etc., to perform data processing and deformation measurement, including:

[0058] S21, satellite selection and data collection, select appropriate radar satellites, such as TerraSAR-X, COSMO-SkyMed, SentInel-1, etc., to provide InSAR data with high resolution and short revisit period;

[0059] S22, extracting high-quality InSAR data at multiple time points, obtaining high-quality InSAR data at multiple time points, including two radar images acquired at different times by interferometry;

[0060] S23, image registration and correction, interferometric image registration, registering the interferometric pair, that is, registering two images collected at different times to ensure accurate spatial alignment of the two images, including phase correction, geometric correction and atmospheric correction of the interferometric pair;

[0061] S24, filtering and noise processing, filtering the phase to remove noise and unstable signals, which helps to improve the accuracy and reliability of the deformation results, and superimpose multiple moments to combine the deformation graphs at multiple moments to reduce the impact of temporary changes and obtain more stable deformation results;

[0062] S25, Verification, ground verification uses ground measured data, such as establishing a measurement control network, GNSS (Global Navigation Satellite System), etc., to verify the InSAR deformation results, improve the credibility of the results, and conduct time series analysis to track the evolution of surface deformation and identify seasonal and long-term deformation trends;

[0063] S3, geological route selection field work, using geological survey, geophysical exploration and drilling to obtain geological information and data within the route corridor, especially the InSAR deformation area;

[0064] S4, internal work of geological line selection, using geotechnical engineering software (such as Lizheng Geotechnical) to establish a geological model of the deformation zone, perform stability analysis and calculation, analyze and determine the deformation cause and trend of the deformation zone, and form a list of distribution of adverse geological features in the corridor, distribution map and text report based on the work of steps S2 and S3, use mapGIS, arcGIS and other software spatial analysis functions to divide the map of areas prone to adverse geology, propose route plans and structure settings for the proposed expressway, and form the results of geological line selection;

[0065] S5, geological route selection effect analysis, monitoring of surface deformation along the expressway during construction and operation, guiding construction and operation maintenance, technical summary of geological route selection results, and forming a geological route selection case database;

[0066] S6, the life cycle of the expressway ends and the geological route selection ends;

[0067] Step S4 uses the information volume method as the basis and adopts GIS software to perform spatial quantitative analysis. The specific steps of the information volume method are as follows:

[0068] S41, the information volume model is derived from the combination of statistical models and information theory. It was first used for mineral exploration. The idea of ​​using it in susceptibility evaluation is to extract the distribution of geological disaster points in the area where geological disasters have occurred, select a certain number of factors, and convert the measured data in the study area into quantifiable information volume values, so as to use it as a quantitative indicator to measure the susceptibility of geological disasters. The information volume value is expressed by the formula:

[0069]

[0070] Among them, I ij is the information value of the jth category of the ith evaluation factor, N ij is the number of geological disasters of the jth type in the ith evaluation factor, N is the total number of geological disasters in the study area, S ij is the number of grid cells of the jth category with the ith evaluation factor, S is the total number of evaluation units in the study area, and after determining the total number of evaluation factors n, the total information value I of the evaluation unit is calculated by the following formula:

[0071]

[0072] The total information value I is used to determine the susceptibility level of the study unit. The larger the comprehensive information value of each evaluation index in the unit, the more favorable it is for the occurrence of geological disasters, and the higher its susceptibility level. The information amount is superimposed on each unit in the study area, and the units are divided into different levels of prone areas according to the size of the comprehensive information amount.

[0073] The embodiment of the present invention is also implemented through the following technical solutions.

[0074] In the embodiment of the present invention, the phase correction in step S23 is to use the phase information of the two images to perform phase analysis to obtain a phase difference map, and the specific steps are as follows:

[0075] S231, remove the flat earth phase, simulate the flat earth model using DEM and subtract it from the interferogram to remove it;

[0076] S232, terrain phase correction, uses DEM to simulate the phase change caused by terrain and subtracts it from the interferogram to eliminate the influence of terrain on the phase;

[0077] S233, Phase Filtering, applies filtering techniques to reduce noise and outliers and improve the signal-to-noise ratio of phase data.

[0078] In the embodiment of the present invention, the geometric correction in step S23 uses the phase difference map to calculate the deformation of the ground surface in the direction of the radar line of sight. The deformation amount is usually calculated by differential measurement, that is, the phase difference between two time points. The calculation steps of the deformation amount are as follows:

[0079] A, interferometric pair selection, two InSAR images with similar time points are selected as interferometric pairs to ensure that the observed phase changes are mainly due to surface displacement rather than other factors such as seasonal changes, plant growth, etc.;

[0080] B, Interference pattern generation, register the two InSAR images to generate the interference pattern;

[0081] C, geometric correction, converts the interferogram in the radar coordinate system to the geographic coordinate system and adjusts the size and shape of the pixels to correspond to the surface features;

[0082] D, deformation calculation, the deformation of the surface in the direction of the radar line of sight (ΔR) is calculated by the following formula:

[0083]

[0084] Among them, λ is the wavelength of the radar wave, Δφ is the phase difference between two time points, B is the baseline length (along the track direction), B⊥ is the vertical component of the baseline, and θ is the incident angle of the radar wave.

[0085] In the embodiment of the present invention, the atmospheric correction in step S23 takes into account the atmospheric influence and performs atmospheric correction to reduce the interference of the atmospheric effect on the interference image. The specific steps are as follows:

[0086] a. Use the atmospheric model to calculate the effect of the atmosphere on radar wave propagation and make corrections;

[0087] b, using InSAR data of different frequencies to separate the effects of atmospheric and non-atmospheric factors;

[0088] d. Identify and remove atmospheric noise by analyzing interference pairs at multiple time points and spatial locations.

[0089] It should be noted that the software and contents involved in the above content are all examples to facilitate the understanding of the use of this application.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0091] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0092] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. A method for geological route selection of mountain highways based on time-series InSAR technology, characterized in that: The following steps are involved: S1, the preparation work before geological route selection is to collect relevant information data along the proposed expressway. Among them, radar satellites should be selected for InSAR data acquisition to obtain image data with high resolution and short revisit period; S2, InSAR data processing and analysis, using professional processing software to process InSAR data and measure deformation; S3, geological route selection field work, using geological survey, geophysical exploration and drilling to obtain geological information and data of InSAR deformation areas within the route corridor; S4, internal work of geological line selection, using geotechnical software to establish a geological model of the deformation zone, perform stability calculation and analysis, analyze and determine the deformation cause and trend of the deformation zone, and form a distribution map, table and text report of adverse geological characteristics in the corridor on the basis of the work in steps S2 and S3, divide the map of areas prone to adverse geological conditions, propose route plans and structure settings for the proposed expressway, and form geological line selection results; S5, geological route selection effect analysis, monitoring of surface deformation along the expressway during construction and operation, guiding construction and operation maintenance, technical summary of geological route selection results, and forming a geological route selection case database; S6, the life cycle of the expressway ends and the geological route selection ends; The step S4 performs a spatial analysis function based on the information volume method. The specific steps of the information volume method are as follows: S41, the information volume model extracts the distribution of geological disaster points in the area where geological disasters have occurred, selects a certain number of factors, and converts the measured data of the study area into quantifiable information volume values, which are used as quantitative indicators to measure the susceptibility of geological disasters. The information volume value is expressed by the formula: Among them, I ij is the information value of the jth category of the ith evaluation factor, N ij is the number of geological disasters of the jth type in the ith evaluation factor, N is the total number of geological disasters in the study area, S ij is the number of grid cells of the jth category with the ith evaluation factor, S is the total number of evaluation units in the study area, and after determining the total number of evaluation factors n, the total information value I of the evaluation unit is calculated by the following formula: The total information value I is used to determine the susceptibility level of the study unit. The larger the comprehensive information value of each evaluation index in the unit, the more favorable it is for the occurrence of geological disasters, and the higher its susceptibility level. The information amount is superimposed on each unit in the study area, and the units are divided into different levels of prone areas according to the size of the comprehensive information amount.

2. The method for geological route selection of mountain highways based on time series InSAR technology according to claim 1 is characterized in that: The expressway information data in step S1 includes expressway project proposals, engineering feasibility study reports, topographic maps within the proposed expressway corridor, regional geological data, geological disaster prevention and control plans, and geological disaster survey and design documents.

3. The method for geological route selection of mountain highways based on time-series InSAR technology according to claim 1 is characterized in that: The specific steps of step S2 are as follows: S21, satellite selection and data collection, select the appropriate radar satellite; S22, extracting high-quality SAR data at multiple time points, obtaining high-quality SAR data at multiple time points, including two radar images collected at different times by interferometry; S23, image registration and correction, interferometric image registration, registration of the interferometric pair, including phase correction, geometric correction and atmospheric correction of the interferometric pair; S24, filtering and noise processing, filtering the phase, removing noise and unstable signals, performing multi-time superposition, combining deformation graphs at multiple times, and obtaining deformation results; S25, Verification, Ground Verification Use ground measured data to verify the InSAR deformation results and perform time series analysis to track the evolution of surface deformation and identify seasonal and long-term deformation trends.

4. The method for geological route selection of mountain highways based on time-series InSAR technology according to claim 3 is characterized in that: The phase correction in step S23 is to use the phase information of the two images to perform phase analysis to obtain a phase difference map. The specific steps are as follows: S231, remove the flat earth phase, simulate the flat earth model using DEM and subtract it from the interferogram to remove it; S232, terrain phase correction, uses DEM to simulate the phase change caused by terrain and subtracts it from the interferogram to eliminate the influence of terrain on the phase; S233, Phase Filtering, applies filtering techniques to reduce noise and outliers.

5. The method for geological route selection of mountain highways based on time-series InSAR technology according to claim 3 is characterized in that: In step S23, the geometric correction uses the phase difference map to calculate the deformation of the ground surface in the direction of the radar line of sight. The deformation amount is usually calculated by differential measurement, that is, the phase difference between two time points. The calculation steps of the deformation amount are as follows: A, interferometric pair selection, selecting two InSAR images with similar time points as interferometric pairs; B, Interference pattern generation, register the two SAR images to generate the interference pattern; C, geometric correction, converts the interferogram in the radar coordinate system to the geographic coordinate system and adjusts the size and shape of the pixels to correspond to the surface features; D, deformation calculation, the deformation of the surface in the direction of the radar line of sight (ΔR) is calculated by the following formula: Among them, λ is the wavelength of the radar wave, Δφ is the phase difference between two time points, B is the baseline length (along the track direction), B⊥ is the vertical component of the baseline, and θ is the incident angle of the radar wave.

6. The method for geological route selection of mountain highways based on time-series InSAR technology according to claim 3 is characterized in that: The specific steps of the atmospheric correction in step S23 are as follows: a. Use the atmospheric model to calculate the effect of the atmosphere on radar wave propagation and make corrections; b, using InSAR data of different frequencies to separate the effects of atmospheric and non-atmospheric factors; d. Identify and remove atmospheric noise by analyzing interference pairs at multiple time points and spatial locations.

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