Degradation level-based extraction and analysis method and system for morphological parameters of mars impact craters

Abstract

The application provides a Mars impact crater shape parameter extraction and analysis method and system based on degradation grading, and relates to the technical field of planetary remote sensing and planetary geology. The method comprises the following steps: dividing impact craters into multiple grades according to degradation degrees, generating a three-dimensional surface of the entire study area; extracting depth data of the impact craters from the overall shape of the impact craters; extracting rim height data of the impact craters from the overall shape of the impact craters; performing linear regression analysis on the depth of each degradation grade impact crater and the diameter of the impact crater, and on the rim height of each degradation grade impact crater and the diameter of the impact crater, obtaining regression parameters, and analyzing the relationship between the shape parameters of the impact craters and the degradation degrees. The application extracts shape parameters from the overall three-dimensional profile of the impact craters, and performs correlation analysis and comparison of the shape parameters of the impact craters in the same grade according to the degradation degree grade, so that the accuracy and precision are higher.

Description

Technical Field

[0001] This invention belongs to the fields of planetary remote sensing and planetary geology, and particularly relates to a method and system for extracting and analyzing Martian impact crater morphology parameters based on degradation grading. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] The classification of impact crater degradation levels and the measurement of morphological parameters provide a powerful tool for analyzing Mars' past climate. Early studies of planetary impact crater morphology relied primarily on measurement techniques from two-dimensional remote sensing images, such as photoclimatology and shading. Later, Martian impact crater studies were based on digital elevation model (DEM) data obtained from the Mars Orbiter Laser Altimeter (MOLA). However, due to the relatively low resolution of MOLA data (~380 m / pixel), crater morphology analysis was mainly focused on craters larger than 5 km in diameter, and the resulting Martian impact crater morphological relationships are not applicable to smaller craters. With the advent of high-resolution cameras on orbital spacecraft, such as the High Resolution Imaging Science Experiment (HiRISE) images and derived DEM data aboard the Mars Reconnaissance Orbiter (MRO), it is possible to quantitatively characterize impact crater shapes at smaller scales, leading to a better understanding of crater formation and evolution. Extending the methods for measuring and analyzing the morphology of Martian impact craters to smaller scales (meter and hundred-meter scales), accurately extracting the morphological features of impact craters (such as diameter, depth, crater rim height, etc.), studying the correlation between morphological parameters, and discussing the geological evolution process and impact crater formation process in the study area are of great significance.

[0004] Due to the diversity of geological processes on planetary surfaces, the complexity of planetary evolution, and the variability of planetary climate, the degradation rate of impact craters on planetary surfaces is discontinuous in time and space. Impact craters are the most prominent morphological and structural features of planetary surfaces, distributed across various geological ages and units. Therefore, the parameter measurement and analysis of impact craters and the assessment of degradation rates can be used to study the evolution of planetary surface processes, the age of geological units, and Martian climate change, among other things. The measurement and analysis of impact crater morphology is of great significance for understanding near-surface stratigraphy, climate evolution, and degradation history. Previous studies on the morphology of Martian impact craters have mainly faced the following two problems:

[0005] (1) In extracting morphological parameters of impact craters, previous studies have mostly used manual profile analysis to measure the depth and rim height of Martian impact craters. First, topographic profiles of the impact crater in four directions (east-west, south-north, northeast-southwest, northwest-southeast) are constructed. The average rim elevation on the four profiles is subtracted from the elevation of the deepest point within the crater to obtain the average depth. The average rim height is obtained by subtracting the rim elevations on the four profiles from the elevations of the terrain outside the rim. Although this method is simple, the four profiles cannot fully reflect the morphological characteristics of the impact crater, and the obtained crater depth and rim height have a certain degree of bias.

[0006] (2) In analyzing the correlation of impact crater morphological parameters, existing methods often combine all impact craters in the study area to conduct correlation analysis of shape parameters (depth, crater rim height, etc.) and diameter, and then perform linear fitting. However, the impact craters in the study area were formed at different times, experienced different geological processes, and were subjected to different degrees of weathering and erosion on the Martian surface. Therefore, the crater rim height and depth will vary with the degree of erosion. Thus, it is necessary to evaluate and classify the degree of degradation of impact craters in the study area, conduct correlation analysis on the shape parameters of impact craters of the same degradation level, and compare the results with those of other degradation levels to obtain the variability of impact crater parameters over time. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, this invention provides a method and system for extracting and analyzing the morphological parameters of Martian impact craters based on degradation grading. The method extracts shape parameters from the overall three-dimensional cross-section of the impact crater and conducts correlation analysis and comparison of the shape parameters of impact craters of the same degradation level, which has higher accuracy and precision.

[0008] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0009] The first aspect of this invention provides a method for extracting and analyzing the morphological parameters of Martian impact craters based on degradation grading.

[0010] A method for extracting and analyzing Martian impact crater morphology parameters based on degradation gradation includes the following steps:

[0011] Step 1: Divide the impact craters into multiple levels according to their degree of degradation, and at the same time obtain a high-precision digital elevation model dataset of the study area to generate the three-dimensional surface of the impact craters in the entire study area.

[0012] Step 2: Based on the three-dimensional surface data of the impact craters in the entire study area, interpolate to establish the three-dimensional surface of each impact crater. Based on the three-dimensional surface of the impact crater established by interpolation, extract the depth data of the impact crater from the overall morphology of the impact crater.

[0013] Step 3: Based on the three-dimensional surface data of the impact craters in the entire study area, interpolate to establish the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater edge ring for each impact crater. Based on the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater edge ring, extract the crater edge height data from the overall morphology of the impact crater.

[0014] Step 4: Perform linear regression analysis on the depth and diameter of impact craters for each degradation level, and on the crater rim height and diameter of impact craters to obtain regression parameters and analyze the relationship between the shape parameters of impact craters and the degree of degradation.

[0015] Preferably, step one further includes generating a set of boundary lines for each impact crater edge in multiple degradation levels and measuring the diameter of each impact crater.

[0016] Preferably, step two specifically includes:

[0017] S201: Determine the diameter and crater boundary line of the impact crater to be extracted, and generate equally spaced points on its crater boundary line in proportion to the diameter of the impact crater to be extracted.

[0018] S202: Based on the three-dimensional surface data of the impact crater in the entire study area, find the elevation value of each equally spaced point, generate a set of crater edge elevation points, and use the linear interpolation function method to construct the three-dimensional surface of the impact crater to be extracted.

[0019] S203: Subtract the elevation values ​​of the three-dimensional surface data of the impact crater in the entire study area from the elevation values ​​of the impact crater three-dimensional surface generated by linear interpolation to obtain the impact crater depth dataset. Extract the maximum value from it, which is the depth of the impact crater.

[0020] S204: Extract the depth of all impact craters of multiple degradation levels using the methods described in S201-S203 above, to obtain the depth of all impact craters in the study area.

[0021] Preferably, step three specifically includes:

[0022] S301: Determine the diameter and crater edge boundary line of the impact crater to be extracted. Based on the crater edge boundary line of the impact crater to be extracted, generate a 1D buffer zone with the diameter of the impact crater outside the impact crater. The closed boundary line of the 1D buffer zone is the initial plain boundary line before the impact.

[0023] S302: Generate equally spaced points on the initial plain boundary line before the impact, proportional to the diameter of the impact crater, according to the parameters to be extracted.

[0024] S303: Based on the three-dimensional surface data of the impact crater in the entire study area, find the elevation values ​​of each equally spaced point on the boundary line of the initial plain before impact, generate the set of elevation points of the initial plain, and construct the three-dimensional surface of the initial plain before impact using the linear interpolation function method.

[0025] S304: Generate a 0.2D buffer zone with a diameter of 0.2 times the impact crater rim as the center, extending into and outward from the impact crater rim, and extract the boundary line of the 0.2D buffer zone;

[0026] S305: Subtract the elevation value of the initial plain three-dimensional surface before impact from the elevation value of the three-dimensional surface of the impact crater in the entire study area to obtain the crater edge height dataset. Extract the maximum value of the crater edge height dataset from the boundary line of the 0.2D buffer zone, which is the crater edge height.

[0027] S306: Extract the crater edge height of all impact craters of multiple degradation levels according to the methods described in S301-S305 above, and obtain the crater edge height of all impact craters in the study area.

[0028] Preferably, step four specifically includes:

[0029] A two-dimensional dot plot was constructed with the diameter of the impact crater as the independent variable and the depth of the impact crater as the dependent variable. The relationship between depth and diameter was studied using linear regression.

[0030] A two-dimensional dot plot was constructed with the crater diameter as the independent variable and the crater rim height as the dependent variable. The linear regression method was used to study the relationship between the crater rim height and the diameter.

[0031] All impact craters at multiple degradation levels were studied using the method described above, and linear regression parameters for the depth and diameter, and the crater rim height and diameter of impact craters at different degradation levels in the study area were obtained.

[0032] Preferably, step one further includes:

[0033] Draw the outline of the impact crater, identify the impact crater, and obtain the impact crater vector file. The vector file contains two types of data: the center point and the diameter of the impact crater.

[0034] Preferably, the impact craters are divided into seven degradation levels, named impact craters 1-7, with level 1 being the freshest impact crater and level 7 being the most degraded impact crater.

[0035] The second aspect of this invention provides a system for extracting and analyzing Martian impact crater morphology parameters based on degradation grading.

[0036] A system for extracting and analyzing Martian impact crater morphology parameters based on degradation grading includes:

[0037] The DEM 3D surface acquisition module is configured to: classify impact craters into multiple levels according to the degree of degradation, acquire a high-precision digital elevation model dataset of the study area, and generate the 3D surface of the impact craters in the entire study area.

[0038] The depth data extraction module is configured to: interpolate and establish a three-dimensional surface of each impact crater based on the three-dimensional surface data of the impact craters in the entire study area; and extract the depth data of the impact craters from the overall morphology of the impact craters based on the three-dimensional surface of the impact craters established by interpolation.

[0039] The crater rim height data extraction module is configured to: based on the three-dimensional surface data of the impact craters in the entire study area, interpolate to establish the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater rim for each impact crater; and extract the crater rim height data from the overall morphology of the impact crater based on the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater rim.

[0040] The linear regression analysis module is configured to perform linear regression analysis on the depth and diameter of impact craters, and the crater rim height and diameter of impact craters for each degradation level, to obtain regression parameters and analyze the relationship between the shape parameters of impact craters and the degree of degradation.

[0041] A third aspect of the present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps in the method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading as described in the first aspect of the present invention.

[0042] The fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps in the method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading as described in the first aspect of the present invention.

[0043] The above one or more technical solutions have the following beneficial effects:

[0044] (1) This invention provides a method and system for extracting and analyzing the morphological parameters of Martian impact craters based on degradation gradation. In the process of calculating and extracting the shape parameters (depth and edge height) of Martian impact craters, the spatial discontinuity of the crater shape is considered. A three-dimensional surface of the impact crater, a three-dimensional surface of the initial plain before impact, and a three-dimensional surface of the crater rim are established through interpolation of high-precision DEM data of the study area. The shape parameters of the impact crater are extracted based on the overall morphology of the crater. Compared with previous studies using the four-directional contour analysis method to measure the depth and rim height of impact craters, this method has higher accuracy and precision.

[0045] (2) This invention considers the uneven degradation and erosion of Martian impact craters when conducting correlation analysis of their shape parameters. The impact craters in the Martian study area have undergone long-term space weathering and geological evolution, exhibiting varying degrees of erosion and degradation. Based on the morphology and degradation degree of the impact craters, this invention classifies them into different degradation levels, and conducts correlation analysis on the depth, crater rim height, and diameter of each degradation level to obtain regression parameters. This method, compared to previous studies that combined all impact craters without considering degradation degree and conducted a single parameter correlation analysis, has higher accuracy and more reasonable scientific significance.

[0046] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0047] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0048] Figure 1 A classification map showing the impact craters identified in the study area and their degree of degradation.

[0049] Figure 2 This is a flowchart of the impact crater depth extraction process in Example 1.

[0050] Figure 3 This is a flowchart of the process for extracting the crater rim height in Example 1.

[0051] Figure 4 This is a graph showing the relationship between the maximum depth and diameter of impact craters from CII to CVII.

[0052] Figure 5 This is a graph showing the relationship between the maximum crater rim height and diameter of impact craters from CII to CVII.

[0053] Figure 6 This is a flowchart of the method in the first embodiment.

[0054] Figure 7 This is a system structure diagram of the second embodiment. Detailed Implementation

[0055] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0056] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0057] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0058] Example 1

[0059] This embodiment discloses a method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading.

[0060] like Figure 6 As shown, the method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading includes the following steps:

[0061] Step 1: Divide the impact craters into multiple levels according to their degree of degradation, and at the same time obtain a high-precision digital elevation model dataset of the study area to generate the three-dimensional surface of the impact craters in the entire study area.

[0062] Step 2: Based on the three-dimensional surface data of the impact craters in the entire study area, interpolate to establish the three-dimensional surface of each impact crater. Based on the three-dimensional surface of the impact crater established by interpolation, extract the depth data of the impact crater from the overall morphology of the impact crater.

[0063] Step 3: Based on the three-dimensional surface data of the impact craters in the entire study area, interpolate to establish the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater edge ring for each impact crater. Based on the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater edge ring, extract the crater edge height data from the overall morphology of the impact crater.

[0064] Step 4: Perform linear regression analysis on the depth and diameter of impact craters for each degradation level, and on the crater rim height and diameter of impact craters to obtain regression parameters and analyze the relationship between the shape parameters of impact craters and the degree of degradation.

[0065] Specifically, it includes:

[0066] Step 1: Mapping and classifying impact craters in the Mars research area.

[0067] The impact crater outline was drawn using a three-point circle method, selecting the highest points of the three crater edges, resulting in an impact crater vector file S. Each impact crater was manually edited to ensure optimal matching between the vector file and the edge geometry. Vector file S contains two types of data: the impact crater center point and the diameter D. The drawn impact craters were classified into seven degradation levels based on five descriptive factors: rocks, sand ripples, edge gaps, edge sharpness, and superimposed impact craters, ranging from CI to CVII (the middle five levels being CII, CIII, CIV, CV, and CVI), with the degradation level increasing sequentially.

[0068] Generate a set of impact crater rim boundary lines from SI to SVII. Each impact crater rim boundary is a closed circular or near-circular line segment, corresponding to seven levels of degradation. Measure the diameter D of each impact crater in the study area. The high-precision digital elevation model dataset corresponding to the study area is a DEM, and linear interpolation is used to generate the three-dimensional surface DEM_S of the impact craters throughout the study area.

[0069] Step 2: Depth extraction of impact craters in the study area.

[0070] The depth (d) of an impact crater is defined as the elevation difference between the highest point of the crater rim and the deepest point of the crater bottom; that is, the maximum difference between the three-dimensional elevation surface of the crater rim and the corresponding crater bottom elevation. The crater rim boundary line SI of the m-th impact crater CIm in the SI dataset with CI degradation levels is given. m For example.

[0071] (1) Based on the diameter CIm of the impact crater CIm m _D proportional to SI m Equally spaced points are generated along the boundary line. The number of spacing points is N_B = CI. m _D*k, where k is the proportionality coefficient.

[0072] (2) Based on the elevation data DEM_S of the study area, find the elevation value of each interval point on the edge boundary of the impact crater CIm, and generate the impact crater CI. m DEM_CI (Elevation Set of Pit Edges) m Then, the impact crater CI was constructed using a linear interpolation function method. m The three-dimensional surface Sur_C.

[0073] (3) Subtract the elevation value of the three-dimensional surface Sur_C at the edge of the impact crater from the elevation value of the three-dimensional surface DEM_S at the corresponding location to obtain the impact crater depth dataset, and extract the maximum value from it to obtain the depth CIm_d of the impact crater CIm.

[0074] (4) Apply this method to other impact craters in the SI dataset of CI degradation level, and to all impact craters from CII to CVII, to obtain the depth of all impact craters in the study area.

[0075] Step 3: Extract the rim height of the impact crater in the study area.

[0076] The crater rim height is defined as the height difference between the top of the crater rim and the initial plain (topography) before impact. Since impact and subsequent geological processes alter the elevation of the area surrounding the crater before its formation, it is necessary to construct an elevation surface of the initial plain before impact. Previous research indicates that the extent of Martian impact crater ejecta is related to its diameter, approximately one diameter (1D). Therefore, extending 1D outward from the crater rim boundary is precisely the boundary by which the crater can alter the pre-impact topography. The crater rim boundary line SI of the m-th crater CIm in the SI dataset with CI degradation levels is shown. m For example.

[0077] (1) Using the buffer analysis method, with SI m A buffer zone with a crater diameter of 1D is generated outside the crater based on the existing buffer zone. The closed boundary of this buffer zone is SI. m _Bur represents the initial plain boundary line before the impact.

[0078] (2) Based on the diameter CIm of the impact crater CIm m _D proportional to SI m Equally spaced points are generated on the _Bur boundary line, with the number of points being N_Bur = CI. m _D*k1, where k1 is the proportionality coefficient.

[0079] (3) Based on the elevation data DEM_S of the study area, find the elevation values ​​of each interval point on the initial plain boundary line before the impact, and generate the impact crater CI. m The initial plain elevation point set DEM_CI m Then, the three-dimensional surface Sur_Bur of the pre-impact plain is constructed using a linear interpolation function.

[0080] (4) Since the impact craters in the study area drawn in step one were generated through visual interpretation and manual selection of crater rim points, the crater rim boundary may not be exactly located at the highest point of the crater rim. According to previous research, the width of a Martian impact crater rim is approximately 0.2 times the diameter of the impact crater. Therefore, in order to ensure that the highest point of the crater rim can be obtained, a buffer analysis method is used, with SI... m A buffer zone of 0.2 times the diameter of the impact crater (0.2D) is generated centered on the impact crater, extending inwards and outwards, with a closed boundary of SI. m _Bur_1.

[0081] (5) Subtract the elevation value of the initial plain 3D surface Sur_Bur at the corresponding location from the DEM_S elevation value of the impact crater 3D surface, to obtain the impact crater rim height dataset, and extract it from the crater rim buffer SI. m The maximum value extracted from the range _Bur_1 is the crater edge height CIm_H of the impact crater CIm.

[0082] (6) The method was applied to other impact craters in the SI dataset of CI degradation level and all impact craters from CII to CVII to obtain the crater edge height of all impact craters in the study area.

[0083] Step 4: Correlation analysis of impact crater shape parameters (depth and crater rim height) based on degradation grading.

[0084] To investigate the relationship between the morphological parameters of impact craters and the degree of degradation over time, a correlation analysis of the shape parameters of impact craters at degradation levels CI to CVII was conducted. Specifically, two-dimensional scatter plots were created for the depth d and diameter D of impact craters at each degradation level, and linear regression analysis was performed on the crater rim height H and diameter D. All impact craters in the SI dataset at the CI degradation level were used as examples.

[0085] (1) A two-dimensional dot plot was constructed with the diameter D of the impact crater as the independent variable and the depth d of the impact crater as the dependent variable. The relationship between the depth and diameter of the impact crater in the CI degradation level of the study area was investigated using linear regression, with the formula d = a1 × D. Where a1 is the linear regression parameter of the impact crater depth and diameter in the CI degradation level.

[0086] (2) A two-dimensional dot plot was constructed with the diameter D of the impact crater as the independent variable and the crater rim height H as the dependent variable. The relationship between the crater rim height and diameter of the impact crater in the CI degradation level of the study area was investigated using linear regression, with the formula H = b1 × D. Where b1 is the linear regression parameter of the crater rim height and diameter in the CI degradation level.

[0087] (3) This method was applied to all impact craters in degradation grades CII to CVII, and linear regression parameters a2 to a7 for the depth and diameter of impact craters with different degradation levels in the study area, and linear regression parameters b2 to b7 for the crater rim height and diameter were obtained. The relationship between the shape parameters of the impact craters in the study area and the degree of degradation was compared and analyzed.

[0088] In this embodiment, the study area is selected as a 134 square kilometer region surrounding the "Zhurong" Mars rover:

[0089] Tianwen-1 was launched in July 2020, successfully entered Mars orbit in February 2021, and landed on the southern part of Utopia Planitia on the Martian surface on May 15. The landing site is located at... Figure 1 Marked with a red five-pointed star. On May 22 of the same year, the "Zhurong" Mars rover safely departed from the landing platform and reached the Martian surface, beginning its exploration. The example study area of ​​this invention selects a 134 square kilometer area around the "Zhurong" Mars rover ( Figure 1(As shown). The images obtained by the High Resolution Imaging Scientific Experiment Camera (HiRISE) have a resolution of approximately 0.25 meters per pixel. This invention selects HiRISE images covering the study area to identify the original impact crater and classify its degree of degradation.

[0090] When classifying impact craters based on their morphological characteristics and degradation levels in the study area:

[0091] First, original impact craters with a diameter of 20 meters or more in the study area were identified and mapped. For example... Figure 1 As shown, the circles of different colors represent the identified impact craters. In this invention, a total of 2,625 impact craters were identified in the study area.

[0092] Then, through visual interpretation using five descriptive factors and morphological features, the 2,625 identified impact craters were divided into seven degradation levels, including one Class CI impact crater, 63 Class CII impact craters, 123 Class CIII impact craters, 137 Class CIV impact craters, 225 Class CV impact craters, 515 Class CVI impact craters, and 1,561 Class CVII impact craters.

[0093] Measurement and analysis of impact crater depth and edge height:

[0094] like Figure 2 and Figure 3 As shown, using the impact crater shape parameter calculation method proposed in this invention, the depth and crater edge height of an impact crater with a CII level degradation are extracted as examples. Figure 2 This is a flowchart of the depth extraction of the impact crater in Example 1, where Figures a to d represent the steps corresponding to the extraction process, and Figure e is a three-dimensional display of the extraction result; Figure 3 This is a flowchart of the crater edge height extraction process in Example 1, where figures a to e represent the steps in the extraction process, and figure f is a three-dimensional display of the edge height extraction result.

[0095] like Figure 2 As shown, Figure 2 A schematic diagram illustrating the depth extraction of an impact crater at CII-level degradation. Figure 2 Figure a shows a CII-level degradation impact crater in the study area, with the red line representing the identified and extracted crater boundary. Figure 2 Figure b in the figure shows the surface generated by linear interpolation after setting spacing points and extracting elevation values ​​for the pit edge boundary line. Figure 2 Figure c shows the transformation of the surface into a raster image with the same resolution as the DEM of the study area. Figure 2 The d-figure in the figure shows the result of subtracting the DEM elevation values ​​of the study area from the surface elevation values ​​generated by the pit edge spacing points. Figure 2 The figure in e is Figure 2The 3D result of the d-plot is displayed.

[0096] like Figure 3 As shown, Figure 3 A schematic diagram illustrating the extraction of the rim height of an impact crater at a CII-level degradation level. Figure 3 Figure a shows a CII-level degraded impact crater in the study area. The blue and yellow lines are the boundary lines for identifying the crater rim and the initial plain boundary line before impact, which is one crater diameter, respectively. Figure 3 Figure b in the figure shows the surface generated by linear interpolation after setting spacing points and extracting elevation values ​​for the pit edge boundary line. Figure 3 Figure c shows the transformation of the surface into a raster image with the same resolution as the DEM of the study area. Figure 3 The d-figure in the figure shows the buffer zones of 0.2 impact crater diameters generated inward and outward from the boundary line of the impact crater rim. Figure 3 The figure in e is Figure 3 The result in Figure d shows the DEM elevation values ​​of the study area minus the surface elevation values ​​generated by the crater edge spacing points within the buffer zone of 0.2 impact crater diameters. Figure 3 The f-graph in the middle is Figure 3 The three-dimensional result of the e-plot is displayed.

[0097] The above method was then applied to depth extraction of 2625 impact craters in the study area. Due to overlapping / crossing edges with other landforms, or proximity to the study area boundary, 69 impact craters that did not meet the edge height calculation criteria were excluded. Therefore, edge height measurements were performed on 2556 impact craters in the study area. Finally, as... Figure 4 and Figure 5 As shown, two-dimensional point plots of impact crater depth and diameter, and impact crater edge height and diameter were generated and linear regression analysis was performed according to the degradation level of impact craters in the study area. The linear fitting results are listed in Table 1.

[0098] Figure 4 This is a graph showing the relationship between the maximum depth and diameter of impact craters from Class C1 to CVII. Figure 4 Figures a through f show the relationship between the maximum depth and diameter of impact craters from CII to CVII, respectively, with the linear fitting results of the d / D values ​​for each class shown in the figures.

[0099] Figure 5 This is a graph showing the relationship between the maximum crater rim height and diameter of impact craters from CII to CVII. Figure 5 Figures a through f in the figure show the relationship between the maximum crater rim height and diameter of impact craters from CII to CVII, respectively. The linear fitting results of the H / D values ​​for each grade are shown in the figure.

[0100] Table 1: Regression statistics of depth and diameter, and crater rim height and diameter for impact craters of classes CI to CVII in this invention.

[0101]

[0102] By comparing the fitting trends of depth, edge height and diameter of impact craters from Class CI to Class CVII, it was found that they are consistent with the degree of degradation of impact craters in the study area, that is, the depth and edge height decrease monotonically as the degree of impact crater degradation increases.

[0103] Example 2

[0104] This embodiment discloses a system for extracting and analyzing Martian impact crater morphology parameters based on degradation grading.

[0105] like Figure 7 As shown, the system for extracting and analyzing Martian impact crater morphology parameters based on degradation grading includes:

[0106] The DEM 3D surface acquisition module is configured to: classify impact craters into multiple levels according to the degree of degradation, acquire a high-precision digital elevation model dataset of the study area, and generate the 3D surface of the impact craters in the entire study area.

[0107] The depth data extraction module is configured to: interpolate and establish a three-dimensional surface of each impact crater based on the three-dimensional surface data of the impact craters in the entire study area; and extract the depth data of the impact craters from the overall morphology of the impact craters based on the three-dimensional surface of the impact craters established by interpolation.

[0108] The crater rim height data extraction module is configured to: based on the three-dimensional surface data of the impact craters in the entire study area, interpolate to establish the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater rim for each impact crater; and extract the crater rim height data from the overall morphology of the impact crater based on the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater rim.

[0109] The linear regression analysis module is configured to perform linear regression analysis on the depth and diameter of impact craters, and the crater rim height and diameter of impact craters for each degradation level, to obtain regression parameters and analyze the relationship between the shape parameters of impact craters and the degree of degradation.

[0110] Example 3

[0111] The purpose of this embodiment is to provide a computer-readable storage medium.

[0112] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading as described in Embodiment 1 of this disclosure.

[0113] Example 4

[0114] The purpose of this embodiment is to provide an electronic device.

[0115] An electronic device includes a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps in the method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading as described in Embodiment 1 of this disclosure.

[0116] The steps and methods involved in the apparatuses of Embodiments 2, 3, and 4 above correspond to those in Embodiment 1. For specific implementation details, please refer to the relevant description section of Embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood as including any medium capable of storing, encoding, or carrying an instruction set for execution by a processor and enabling the processor to perform any of the methods in this invention.

[0117] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0118] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading, characterized in that, Includes the following steps: Step 1: Divide the impact craters into multiple levels according to their degree of degradation, and at the same time obtain a high-precision digital elevation model dataset of the study area to generate the three-dimensional surface of the impact craters in the entire study area. Step 2: Based on the three-dimensional surface data of the impact craters in the entire study area, interpolate to establish the three-dimensional surface of each impact crater. Based on the three-dimensional surface of the impact crater established by interpolation, extract the depth data of the impact crater from the overall morphology of the impact crater. Specifically, this includes: S201: Determine the diameter and crater edge boundary line of the impact crater to be extracted, and generate equally spaced points on its crater edge boundary line in proportion to the diameter of the impact crater to be extracted. S202: Based on the three-dimensional surface data of the impact crater in the entire study area, find the elevation value of each equally spaced point, generate a set of crater edge elevation points, and use the linear interpolation function method to construct the three-dimensional surface of the impact crater to be extracted. S203: Subtract the elevation values ​​of the three-dimensional surface data of the impact crater in the entire study area from the elevation values ​​of the impact crater three-dimensional surface generated by linear interpolation to obtain the impact crater depth dataset. Extract the maximum value from it, which is the depth of the impact crater. S204: Extract the depth of all impact craters of multiple degradation levels using the methods described in S201-S203 above, to obtain the depth of all impact craters in the study area; Step 3: Based on the three-dimensional surface data of the impact craters throughout the study area, interpolation is used to establish the initial three-dimensional plain surface and the crater rim ring surface of each impact crater before impact. Based on the initial three-dimensional plain surface and the crater rim ring surface, the crater rim height data is extracted from the overall morphology of the impact crater, specifically including: S301: Determine the diameter and crater edge boundary line of the impact crater to be extracted. Based on the crater edge boundary line of the impact crater to be extracted, generate a 1D buffer zone with the diameter of the impact crater outside the impact crater. The closed boundary line of the 1D buffer zone is the initial plain boundary line before the impact. S302: Generate equally spaced points on the initial plain boundary line before the impact, proportional to the diameter of the impact crater, according to the parameters to be extracted. S303: Based on the three-dimensional surface data of the impact crater in the entire study area, find the elevation values ​​of each equally spaced point on the boundary line of the initial plain before impact, generate the set of elevation points of the initial plain, and construct the three-dimensional surface of the initial plain before impact using the linear interpolation function method. S304: Generate a 0.2D buffer zone with a diameter of 0.2 times the impact crater rim as the center, extending into and out of the impact crater, and extract the boundary line of the 0.2D buffer zone; S305: Subtract the elevation value of the initial plain three-dimensional surface before impact from the elevation value of the three-dimensional surface of the impact crater in the entire study area to obtain the crater edge height dataset. Extract the maximum value of the crater edge height dataset from the boundary line of the 0.2D buffer zone, which is the crater edge height. S306: Extract the crater edge height of all impact craters of multiple degradation levels according to the methods described in S301-S305 above, and obtain the crater edge height of all impact craters in the study area. Step 4: Perform linear regression analysis on the depth and diameter of impact craters for each degradation level, and on the crater rim height and diameter of impact craters to obtain regression parameters and analyze the relationship between the shape parameters of impact craters and the degree of degradation.

2. The method for extracting and analyzing Martian impact crater morphology parameters based on degradation gradation as described in claim 1, characterized in that, Step one also includes generating a set of boundary lines for each impact crater edge in multiple degradation levels and measuring the diameter of each impact crater.

3. The method for extracting and analyzing Martian impact crater morphology parameters based on degradation gradation as described in claim 1, characterized in that, Step four specifically includes: A two-dimensional dot plot was constructed with the diameter of the impact crater as the independent variable and the depth of the impact crater as the dependent variable. The relationship between depth and diameter was studied using linear regression. A two-dimensional dot plot was constructed with the crater diameter as the independent variable and the crater rim height as the dependent variable. The linear regression method was used to study the relationship between the crater rim height and the diameter. All impact craters at multiple degradation levels were studied using the method described above, and linear regression parameters for the depth and diameter, and the crater rim height and diameter of impact craters at different degradation levels in the study area were obtained.

4. The method for extracting and analyzing Martian impact crater morphology parameters based on degradation gradation as described in claim 1, characterized in that, Step one also includes: Draw the outline of the impact crater, identify the impact crater, and obtain the impact crater vector file. The vector file contains two types of data: the center point and the diameter of the impact crater.

5. The method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading as described in claim 4, characterized in that, The impact craters were classified into seven degradation levels, named 1-7, with level 1 being the newest and level 7 being the most degraded.

6. A system for extracting and analyzing Martian impact crater morphology parameters based on degradation grading, characterized in that: include: The DEM 3D surface acquisition module is configured to: classify impact craters into multiple levels according to the degree of degradation, acquire a high-precision digital elevation model dataset of the study area, and generate the 3D surface of the impact craters in the entire study area. The depth data extraction module is configured to: interpolate and establish a three-dimensional surface of each impact crater based on the three-dimensional surface data of the impact craters in the entire study area; and extract the depth data of the impact craters from the overall morphology of the impact craters based on the three-dimensional surface of the impact craters established by interpolation. Specifically, it includes: S201: determining the diameter and crater edge boundary line of the impact crater to be extracted, and generating equally spaced points on its crater edge boundary line in proportion to the diameter of the impact crater to be extracted. S202: Based on the three-dimensional surface data of the impact crater in the entire study area, find the elevation value of each equally spaced point, generate a set of crater edge elevation points, and use the linear interpolation function method to construct the three-dimensional surface of the impact crater to be extracted. S203: Subtract the elevation values ​​of the three-dimensional surface data of the impact crater in the entire study area from the elevation values ​​of the impact crater three-dimensional surface generated by linear interpolation to obtain the impact crater depth dataset. Extract the maximum value from it, which is the depth of the impact crater. S204: Extract the depth of all impact craters of multiple degradation levels using the methods described in S201-S203 above, to obtain the depth of all impact craters in the study area; The crater edge height data extraction module is configured to: based on the three-dimensional surface data of the impact crater in the entire study area, interpolate to establish the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater edge ring for each impact crater; based on the three-dimensional surface of the initial plain before impact and the three-dimensional surface of the crater edge ring, extract the crater edge height data of the impact crater from the overall morphology of the impact crater, specifically including: S301: determine the diameter and crater edge boundary line of the impact crater to be extracted, and generate a 1D buffer of the impact crater diameter outside the impact crater based on the crater edge boundary line of the impact crater to be extracted, and the closed boundary line of the 1D buffer is the boundary line of the initial plain before impact; S302: Generate equally spaced points on the initial plain boundary line before the impact, proportional to the diameter of the impact crater, according to the parameters to be extracted. S303: Based on the three-dimensional surface data of the impact crater in the entire study area, find the elevation values ​​of each equally spaced point on the boundary line of the initial plain before impact, generate the set of elevation points of the initial plain, and construct the three-dimensional surface of the initial plain before impact using the linear interpolation function method. S304: Generate a 0.2D buffer zone with a diameter of 0.2 times the impact crater rim as the center, extending into and out of the impact crater, and extract the boundary line of the 0.2D buffer zone; S305: Subtract the elevation value of the initial plain three-dimensional surface before impact from the elevation value of the three-dimensional surface of the impact crater in the entire study area to obtain the crater edge height dataset. Extract the maximum value of the crater edge height dataset from the boundary line of the 0.2D buffer zone, which is the crater edge height. S306: Extract the crater edge height of all impact craters of multiple degradation levels according to the methods described in S301-S305 above, and obtain the crater edge height of all impact craters in the study area. The linear regression analysis module is configured to perform linear regression analysis on the depth and diameter of impact craters, and the crater rim height and diameter of impact craters for each degradation level, to obtain regression parameters and analyze the relationship between the shape parameters of impact craters and the degree of degradation.

7. A computer-readable storage medium having a program stored thereon, characterized in that, When executed by the processor, the program implements the steps in the method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading as described in any one of claims 1-5.

8. An electronic device, comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps in the method for extracting and analyzing Martian impact crater morphology parameters based on degradation grading as described in any one of claims 1-5.

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