Mountain volume change analysis method and explosion equivalent calculation method

Abstract

The invention provides a mountain volume change analysis method and an explosion equivalent analysis method. According to the method, an initial three-dimensional model of a target mountain is established on the basis of DEM data; obtaining at least three interferograms formed by at least three pairs of SAR images of the target mountain in different sight directions by using the InSAR, reading coordinate information of each pixel point in a difference result corresponding to each interferogram, and obtaining displacement vector matrixes in three respective directions; calculating each single value in the displacement vector matrix to obtain a deformation component of each pixel point in a space rectangular coordinate system; establishing a new three-dimensional model of the target mountain according to the deformation component of each pixel point in the space rectangular coordinate system; and the initial three-dimensional model of the target mountain and the new three-dimensional model of the target mountain are subtracted to obtain the volume change of the target mountain. The problem that the explosion range boundary cannot be clearly distinguished in a traditional method is solved.

Description

Technical Field

[0001] The invention relates to the field of microwave remote sensing technology, and in particular to a mountain volume change analysis method and an explosion equivalent analysis method. Background Art

[0002] At present, the InSAR method is usually used to study the settlement changes of the ground surface. In the process of using the InSAR method, although the InSAR technology can achieve millimeter-level accuracy when processing high-quality microwave remote sensing images, researchers can only obtain the surface changes in the direction of image shooting with this technology. This change cannot replace the technical elements such as elevation, horizontal displacement, and volume change uniformly used by engineering departments. For example, when it is necessary to analyze the explosive equivalent of explosives, the explosives are detonated on the target mountain. Although the deformation of each surface unit in the direction of image shooting can be calculated by InSAR, it cannot effectively show the horizontal displacement and vertical settlement caused by the explosion. Therefore, when judging the impact range of nuclear tests, it will encounter the situation that the explosion range boundary cannot be clearly distinguished and the volume change caused by the explosion cannot be estimated. Summary of the invention

[0003] In order to overcome the defects existing in the above-mentioned prior art, the purpose of the present invention is to provide a mountain volume change analysis method and an explosion equivalent analysis method.

[0004] In order to achieve the above-mentioned object of the present invention, the present invention provides a mountain volume change analysis method, comprising the following steps:

[0005] Based on DEM data, an initial three-dimensional model of the target mountain is established;

[0006] Using InSAR to obtain at least three interference patterns formed by at least three pairs of SAR images of the target mountain in different sight directions, reading the coordinate information of each pixel point in the differential result corresponding to each interference pattern, and obtaining the displacement vector matrix in three respective directions;

[0007] Calculate each value in the displacement vector matrix separately to obtain the deformation component of each pixel in the spatial rectangular coordinate system;

[0008] A new three-dimensional model of the target mountain is established according to the deformation component of each pixel point in the spatial rectangular coordinate system;

[0009] The volume change of the target mountain is obtained by subtracting the initial three-dimensional model of the target mountain from the new three-dimensional model of the target mountain.

[0010] Optionally, a transformation matrix L between three interference pattern coordinate systems and a spatial rectangular coordinate system is obtained according to the angular relationship between the three pairs of SAR images;

[0011] The transformation matrix L is used to transform the displacement vector matrix of each pixel point in the three interference pattern coordinate systems into the spatial rectangular coordinate system:

[0012] D=L -1 R,

[0013] D is the coordinate in the spatial rectangular coordinate system, and R is the displacement vector matrix.

[0014] Optionally, select a point that corresponds one-to-one to each pixel of dem, and calculate the deformation component of each point in the spatial rectangular coordinate system.

[0015] Optionally, the conversion matrix is:

[0016]

[0017] Among them, θ i (i=1, 2, 3) corresponds to the local incident angle of each pair of SAR images in the three pairs of SAR images, α i (i=1, 2, 3) are the satellite headings projected on the horizontal plane measured clockwise from the north, respectively.

[0018] The present invention also proposes an explosion equivalent analysis method, which calculates the volume change of the target mountain before and after the explosion according to the above-mentioned mountain volume change calculation method, and calculates the explosion equivalent according to the volume change.

[0019] The beneficial effects of the present invention are:

[0020] The present invention combines DEM data and the InSAR method, establishes an initial three-dimensional model of a target mountain and a new three-dimensional model of the target mountain, and obtains the volume difference between the two three-dimensional models to realize the analysis of the volume change of the mountain. It can understand the detailed geographical information changes of a certain area without contacting the area, and overcomes the problems of the mismatch between the results of the InSAR method and the coordinate system used daily by the engineering department, the difficulty in quantifying the volume change, and the inability to clearly distinguish the boundaries of the explosion range.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 It is a schematic diagram of the process of the present invention;

[0024] Figures 2 to 4It is the mountain subsidence maps in different directions generated by three pairs of ALOS-2 images at the same location (one pair is descending and needs to be inverted);

[0025] Figure 5 It is a schematic diagram of the initial three-dimensional model of the target mountain before the explosion;

[0026] Figure 6 It is a three-dimensional model of the target mountain after the explosion;

[0027] Figure 7 It is a visual graph of the volume change of the target mountain after the explosion. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, 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 only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0030] Embodiment 1

[0031] like Figure 1 As shown, this embodiment provides a method for calculating the volume change of a mountain, which is used to calculate the volume change of a mountain after an explosion, and specifically includes the following steps:

[0032] In this embodiment, the available DEM data involving the deformation part in the target mountain area consists of only 40,000 to 50,000 pixels. Therefore, 40,000 points of 200×200 are extracted from the explosion area according to the average rule as representatives of the deformation of the deformation area.

[0033] First, based on the DEM data, the initial three-dimensional model of the target mountain is established using the DEM data before the explosion of the target mountain, such as Figure 5 Read the position and elevation information represented by each pixel in the initial 3D model.

[0034] Then, InSAR is used to obtain at least three interferograms formed by at least three pairs of SAR images of the target mountain in different sight directions, such as Figures 2 to 4As shown. Read the coordinate information of each pixel point in the differential result corresponding to each interference pattern to obtain at least three displacement vector matrices in respective directions. Since each number in the displacement vector matrix represents the displacement of a single pixel in the line of sight direction, and the position represented by the number can correspond to the longitude and latitude of this pixel, the coordinate information of each pixel point is the position of the longitude and latitude of each pixel point. The x-axis and y-axis of the spatial rectangular coordinate system are formed by the longitude and latitude grid. The pixel is the smallest unit that can be calculated for high-resolution images. The displacement vector value of the pixel point is calculated to obtain the value of the z-axis change in the spatial rectangular coordinate system. Therefore, each displacement vector matrix is ​​calculated to obtain the deformation component of each pixel point in the spatial rectangular coordinate system. The specific calculation steps are:

[0035] Taking three displacement vector matrices as an example, the displacement vectors of the three interference patterns obtained from three pairs of SAR images can be expressed as a matrix, which is a one-column and three-row matrix, denoted by R, R = [r1, r2, r3] T , r1, r2, r3 are the values ​​of the pixels, representing the displacement in a specific direction of the interference pattern. The matrix does not include coordinates, that is, it does not include longitude and latitude. There are only three numbers in the matrix. For example, in this embodiment, there are 40,000 pixels, and there are 40,000 matrices. These 40,000 matrices need to be calculated separately.

[0036] According to the angular relationship between the three pairs of SAR images, the transformation matrix L between the three interference pattern coordinate systems and the spatial rectangular coordinate system is obtained.

[0037]

[0038] Among them, θ i (i=1, 2, 3) corresponds to the local incident angle of each pair of SAR images in the three pairs of SAR images, α i (i=1, 2, 3) are the satellite headings projected on the horizontal plane measured clockwise from the north, respectively.

[0039] The transformation matrix L is used to transform the displacement vector matrix of each pixel point in the three interference pattern coordinate systems into the spatial rectangular coordinate system:

[0040] D=L -1 R,

[0041] D is the coordinate in the spatial rectangular coordinate system [xyz] T , R is the displacement vector matrix.

[0042] In this embodiment,

[0043] For the data set of this embodiment, L is calculated from the spatial position relationship of three interference patterns, namely, the ascending pair obtained on July 27, 2017 and September 7, 2017, the ascending pair obtained on August 29, 2017 and September 12, 2017, and the descending pair obtained on August 31, 2017 and September 28, 2017. In this case, the specific formula for calculating the deformation of a single pixel in the three directions of x, y, and z in the spatial rectangular coordinate system is:

[0044]

[0045] After InSAR processing of SAR image pairs in three different directions, the ArgGIS tool is used to select points that correspond to each pixel of the DEM, that is, pixels with the same longitude and latitude, and calculate the deformation component of each corresponding pixel in the spatial rectangular coordinate system.

[0046] A new three-dimensional model of the target mountain is established based on the deformation component of each pixel in the spatial rectangular coordinate system, such as Figure 6 shown.

[0047] The volume change of the target mountain is obtained by subtracting the initial 3D model of the target mountain from the new 3D model of the target mountain, such as Figure 7 The volume change of the area before and after the explosion was calculated to be 0.058 cubic kilometers.

[0048] Embodiment 2

[0049] This embodiment provides a method for calculating an explosion equivalent, which calculates the volume change of a target mountain before and after the explosion according to the mountain volume change calculation method described in the first embodiment, and calculates the explosion equivalent according to the calculated volume change.

[0050] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", 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 invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for calculating mountain volume change, characterized in that: The following steps are involved: Based on DEM data, an initial three-dimensional model of the target mountain is established; At least three interference patterns formed by at least three pairs of SAR images of the target mountain in different sight directions are obtained by using InSAR, and the coordinate information of each pixel point in the differential result corresponding to each interference pattern is read to obtain the displacement vector matrix in three respective directions; Calculate each value in the displacement vector matrix to obtain the deformation component of each pixel in the spatial rectangular coordinate system; A new three-dimensional model of the target mountain is established according to the deformation component of each pixel point in the spatial rectangular coordinate system; The volume change of the target mountain is obtained by subtracting the initial three-dimensional model of the target mountain from the new three-dimensional model of the target mountain.

2. The mountain volume change calculation method according to claim 1, characterized in that: According to the angular relationship between the three pairs of SAR images, the transformation matrix L between the three interferogram coordinate systems and the spatial rectangular coordinate system is obtained; The transformation matrix L is used to transform the displacement vector matrix of each pixel point in the three interference pattern coordinate systems into the spatial rectangular coordinate system: D=L -1 R, D is the coordinate in the spatial rectangular coordinate system, and R is the displacement vector matrix.

3. The method for calculating mountain volume change according to claim 2, characterized in that: Select the points that correspond to each pixel of dem one by one, and calculate the deformation component of each point in the spatial rectangular coordinate system.

4. The mountain volume change calculation method according to claim 2, characterized in that: The conversion matrix is: Among them, θ i (i=1, 2, 3) corresponds to the local incident angle of each pair of SAR images in the three pairs of SAR images, α i (i=1, 2, 3) are the satellite headings projected on the horizontal plane measured clockwise from the north, respectively.

5. A method for calculating explosion equivalent, characterized in that: The mountain volume change calculation method according to any one of claims 1 to 4 is used to calculate the target mountain volume change before and after the explosion, and the explosion equivalent is calculated based on the volume change.

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