Information processing apparatus, information processing method, and information processing program

Abstract

To perform high accuracy time-sequence interference analysis by excluding an image pair that is inappropriate as an image pair used for time-sequence interference analysis.SOLUTION: An image pair generation unit 110 generates a plurality of image pairs 41 that are used for time-sequence interference analysis from a plurality of radar images 31 having different observation periods. A pair index value calculation unit 120 calculates an index representing a relationship between radar images included in each image pair, and calculates a pair index value 51 being used for determining whether it is appropriate that the image pair is used for the time-sequence interference analysis by performing statistical analysis of an index. A selection unit 130 excludes the image pairs which are inappropriate from the plurality of image pairs 41 using a threshold value 151 set on the basis of total pair index values of the plurality of image pairs. A time-sequence interference analysis unit 140 performs the time-sequence interference analysis using residual image pairs in which inappropriate image pairs are excluded.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an information processing device, an information processing method, and an information processing program. [Background technology]

[0002] In SAR, a flying object irradiates microwaves onto the ground surface while moving, receives the echoes reflected from the ground surface, and generates SAR images by signal processing the received echoes. Radar images obtained by SAR have amplitude and phase for each pixel. SAR is an abbreviation for Synthetic Aperture Radar. In SAR, by artificially synthesizing an aperture, it is possible to obtain radar images equivalent to those obtained by an antenna with a large aperture.

[0003] In recent years, time-series interferometry analysis has been conducted using multiple radar images obtained at different observation times by SAR. By conducting time-series interferometry analysis, it is possible to measure minute relative displacements on the ground surface. For example, by conducting time-series interferometry analysis using data sets from satellite SAR observations on different observation dates, it is possible to measure ground subsidence caused by construction work or slope deformation caused by landslides.

[0004] In the multiple radar images used in the time-series interference analysis, the conditions at the time of observation of the SAR satellite data are different for each radar image. Therefore, the variation in phase difference or coherence is different for each image pair of radar images used in the time-series interference analysis. The conditions at the time of observation of the SAR satellite data are, for example, differences in weather, ionospheric conditions, or land cover conditions. Generally, the results of time-series interference analysis depend on the quality of the interference analysis results input into the process. Therefore, if there is a large variation in phase difference or coherence, the quality of the results of time-series interference analysis also decreases. Therefore, it was necessary to visually check the interference analysis results and manually remove those with large variations in phase or coherence. With such visual checks, the judgment criteria depended on the operator, which posed an issue of unstable quality. Another issue was that it was difficult to automate the system when expanding the scope of application of time-series interference analysis.

[0005] Patent Document 1 discloses a radar image processing device that can easily select an image with high coherence when performing interference processing on SAR images. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-205146 A Summary of the Invention [Problem to be solved by the invention]

[0007] Patent Document 1 describes the selection of radar images using a predetermined index that affects the interference processing of radar images. However, simply selecting radar images using a predetermined index does not make it clear whether the image pair is a valid image pair compared to all image pairs used in the time-series interference analysis. Therefore, there is a risk that valid image pairs will be excluded, or that invalid image pairs will not be excluded.

[0008] The present disclosure aims to perform more accurate time-series interference analysis by excluding image pairs that are determined to be inappropriate compared to the entire set of image pairs used in the time-series interference analysis. [Means for solving the problem]

[0009] The information processing device according to the present disclosure includes: an image pair generation unit that generates a plurality of image pairs to be used for time-series interference analysis from a plurality of radar images observed at different times; a pair index value calculation unit that calculates an index representing a relationship between radar images included in each of the plurality of image pairs and calculates a pair index value used to determine whether or not it is appropriate to use the image pair in a time-series interference analysis by statistically analyzing the index; a selection unit that uses a threshold value that is set based on all pair index values ​​of the plurality of image pairs to exclude image pairs that are not appropriate as image pairs to be used in a time-series interference analysis from the plurality of image pairs; and a time-series interference analysis unit that performs a time-series interference analysis using the remaining image pairs after excluding the inappropriate image pairs from the plurality of image pairs. Effect of the Invention

[0010] In the information processing device according to the present disclosure, the pair index value calculation unit calculates a pair index value used to determine whether it is appropriate to use an image pair in a time-series interference analysis by statistically analyzing the index. The selection unit uses a threshold value set based on all pair index values ​​of the multiple image pairs to exclude image pairs that are inappropriate as image pairs to be used in the time-series interference analysis from the multiple image pairs. Thus, according to the information processing device according to the present disclosure, it is possible to exclude image pairs that are inappropriate for the entire image pairs from the multiple image pairs to be used in the time-series interference analysis, and to perform a highly accurate time-series interference analysis. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a diagram showing an example of a functional configuration of the information processing device according to the first embodiment. [Diagram 2] 4 is a flowchart showing the operation of the information processing device according to the first embodiment. [Diagram 3] FIG. 4 is a diagram showing an example of a selection process according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing an example of a hardware configuration of the information processing device according to the first embodiment. [Diagram 5]FIG. 4 is a diagram showing another example of the hardware configuration of the information processing device according to the first embodiment. [Figure 6] FIG. 11 is a flowchart showing an example of the operation of the information processing device according to the second embodiment. [Figure 7] FIG. 11 is a diagram showing an example of a functional configuration of an information processing device according to a third embodiment. [Figure 8] FIG. 11 is a flowchart showing the operation of the information processing device according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments will be described with reference to the drawings. In each drawing, the same or corresponding parts are given the same reference numerals. In the description of the embodiments, the description of the same or corresponding parts will be omitted or simplified as appropriate. The arrows in the drawings mainly indicate the flow of data or the flow of processing.

[0013] Embodiment 1 ***Configuration Description*** FIG. 1 is a diagram showing an example of a functional configuration of an information processing device 100 according to the present embodiment. The information processing device 100 is a device that acquires a plurality of radar images 31, performs time-series interference analysis using the plurality of radar images 31, and outputs an analysis result 80 such as the amount of displacement of the ground surface.

[0014] The information processing device 100 includes, as functional elements, an image pair generating unit 110, a pair index value calculating unit 120, a selecting unit 130, a time-series interference analyzing unit 140, and a storage unit 150. The following provides an overview of the functional elements of the information processing device 100.

[0015] The image pair generator 110 acquires a plurality of radar images 31 and generates a plurality of image pairs 41 from the plurality of radar images 31 to be used in time-series interference analysis. The pair index value calculation unit 120 calculates an index representing the relationship between the radar images included in each of the multiple image pairs 41. Then, the pair index value calculation unit 120 performs a statistical analysis of the calculated index to calculate a pair index value 51 used to determine whether or not it is appropriate to use the image pair in a time-series interference analysis. The selection unit 130 uses a threshold value 151 to exclude image pairs that are not appropriate as image pairs to be used in the time-series interference analysis from the multiple image pairs 41. The threshold value 151 is a value that is set based on all pair index values ​​of the multiple image pairs 41. The time-series interference analysis unit 140 executes a time-series interference analysis using selected image pairs 61 that are the remaining image pairs after excluding inappropriate image pairs from the plurality of image pairs 41. The storage unit 150 stores a threshold value 151. The threshold value 151 is a value that is determined in advance by an administrator or the like. The threshold value 151 is set based on the statistical distribution of all pair index values ​​51 of the multiple image pairs 41. Alternatively, the selection unit 130 may set the threshold value 151 based on the statistical distribution of all pair index values ​​51 of the multiple image pairs 41.

[0016] ***Explanation of Operation*** FIG. 2 is a flow diagram showing an example of the operation of information processing device 100 according to the present embodiment. The operation of information processing device 100 according to this embodiment will be described. The operation procedure of information processing device 100 corresponds to an information processing method. Also, a program that realizes the operation of information processing device 100 corresponds to an information processing program.

[0017] <Image pair generation process> In step S101, the image pair generator 110 acquires a plurality of radar images 31, and generates a plurality of image pairs 41 from the plurality of radar images 31 to be used in the time-series interference analysis. Each of the multiple radar images 31 is a SAR image obtained by SAR. The multiple radar images 31 are observed at different times. The multiple radar images 31 are radar images in a time series. Specifically, the following applies:

[0018] The image pair generator 110 acquires a plurality of radar images 31 in time series, and generates a plurality of image pairs 41 by combining each radar image of the plurality of radar images 31 in a round-robin manner. The method of generating the multiple image pairs 41 does not have to be a brute force method. For example, the image pair generating unit 110 may set a master image as a reference from among the multiple radar images 31 in time series, and generate multiple image pairs 41 by combining the master image with a slave image subordinate to the master image.

[0019] <Pair index value calculation process> In step S102, the pair index value calculation unit 120 calculates an index representing the relationship between radar images included in each of the multiple image pairs 41. Here, the index representing the relationship between radar images is an index that may affect the results of the time-series interference analysis. For example, an index representing the relationship between radar images is an index such as the phase difference or coherence between radar images. Then, the pair index value calculation unit 120 performs a statistical analysis of the calculated index to calculate a pair index value 51 used to determine whether the image pair is suitable for use in the time-series interference analysis. The pair index value 51 is a value used to determine whether or not the image pair is suitable for use in the time-series interference analysis. For example, the pair index value calculation unit 120 calculates a standard deviation of the indices of the image pair as the pair index value 51. Alternatively, the pair index value calculation unit 120 may calculate, as the pair index value 51, a statistical value such as the average value, the maximum-minimum range, the variance, or the mode of the indices of the image pair.

[0020] A specific example of this embodiment will be described below. The pair index value calculation unit 120 calculates the coherence as an index for each image pair of the multiple image pairs. The coherence of the image pair is calculated, for example, for each pixel. Then, the pair index value calculation unit 120 calculates the standard deviation of the coherence calculated for the image pair as the pair index value 51 of the image pair. Furthermore, the pair index value calculation unit 120 calculates the phase difference as an index for each of the multiple image pairs. The phase difference of the image pair is calculated, for example, for each pixel. Then, the pair index value calculation unit 120 calculates the standard deviation of the phase difference calculated for the image pair as the pair index value 51 of the image pair.

[0021] The pair index value calculation unit 120 may calculate only the standard deviation of the coherence for each of the multiple image pairs, or may calculate only the standard deviation of the phase difference, or may calculate the standard deviation for both the coherence and the phase difference.

[0022] <Selection process> In step S103, the selection unit 130 uses a threshold value 151 set based on all pair index values ​​of the multiple image pairs to exclude image pairs that are inappropriate as image pairs to be used in the time-series interference analysis from the multiple image pairs 41. The selection unit 130 passes the remaining image pairs, after excluding the inappropriate image pairs from the multiple image pairs 41, to the time-series interference analysis unit 140 as selected image pairs 61. Specifically, the following applies:

[0023] The selection unit 130 acquires the threshold value 151 from the storage unit 150. The threshold value 151 is a value set based on the statistical distribution of the pair index value 51 of each image pair of the multiple image pairs. The threshold value 151 may be set in advance by an administrator or the like. Alternatively, the selection unit 130 may set the threshold value 151 of the pair index value 51 based on the statistical distribution of the pair index value 51 of each image pair of the multiple image pairs.

[0024] An example of a method for setting the threshold 151 is as follows. The threshold value 151 is set based on the statistical distribution of the pair index values ​​of all the multiple image pairs. If the pair index value is the standard deviation of the index, the larger the value, the more spread out the index is, indicating a poor quality image pair. As the statistical distribution of the pair index values, for example, a histogram, a maximum / minimum width, a variance, or a mode is used. From the statistical distribution of the pair index values, the proportion of image pairs to be excluded as being inappropriate for the multiple image pairs is determined, and the threshold value 151 is set.

[0025] When the pair index value is the standard deviation of the index, an image pair whose pair index value 51 is greater than the threshold value 151 is an image pair that is not appropriate for use in time-series interference analysis for all of the multiple image pairs. Therefore, the selection unit 130 excludes image pairs whose pair index value 51 is greater than the threshold value 151 from the multiple image pairs 41. The selection unit 130 passes the remaining image pairs, after excluding the inappropriate image pairs from the multiple image pairs 41, to the time-series interference analysis unit 140 as selected image pairs 61.

[0026] FIG. 3 is a diagram illustrating an example of the selection process according to the present embodiment. 3, a number of radar images “1” to “7” are combined into a number of image pairs 41. For each image pair, the standard deviation of the phase difference and the standard deviation of the coherence are calculated as a pair index value 51. In the diagram of Fig. 3, image pairs marked with a circle indicate image pairs whose pair index value 51 is equal to or less than the threshold value 151. In other words, image pairs marked with a circle are appropriate for use in time-series interference analysis of all image pairs. In the diagram of Fig. 3, image pairs for which a circle is not marked are excluded, and image pairs marked with a circle are selected image pairs 61. The selection unit 130 may leave only image pairs in which a mark "o" is set for both the standard deviation of phase difference and the standard deviation of coherence as the selected image pairs 61. Alternatively, the selection unit 130 may leave image pairs in which a mark "o" is set for either the standard deviation of phase difference or the standard deviation of coherence as the selected image pairs 61. Leaving only image pairs in which a mark "o" is set for both the standard deviation of phase difference and the standard deviation of coherence as the selected image pairs 61 improves the accuracy of the time-series interference analysis.

[0027] <Time series interference analysis processing> In step S104, the time-series interference analysis unit 140 executes a time-series interference analysis using the selected image pair 61, and outputs an analysis result 80 such as the amount of displacement of the ground surface.

[0028] ***Other configurations*** <Variation 1> In the present embodiment, a specific example has been described in which the pair index value calculation unit 120 calculates both the standard deviation of coherence and the standard deviation of phase difference for each image pair of the multiple image pairs as the pair index value 51. However, the pair index value calculation unit 120 may calculate only the standard deviation of coherence for each image pair of the multiple image pairs as the pair index value 51. Alternatively, the pair index value calculation unit 120 may calculate only the standard deviation of phase difference for each image pair of the multiple image pairs as the pair index value 51.

[0029] ***Explanation of the Effects of the Present Embodiment*** As described above, the information processing device according to this embodiment statistically analyzes the indexes of the image pairs to calculate pair index values ​​used to determine whether the image pairs are appropriate for use in the time-series interference analysis. Then, the information processing device according to this embodiment uses a threshold value set based on all pair index values ​​of the multiple image pairs to exclude image pairs that are inappropriate as image pairs to be used in the time-series interference analysis from the multiple image pairs. Therefore, according to the information processing device of this embodiment, it is possible to appropriately remove image pairs that are not appropriate for all the image pairs from the multiple image pairs used in the time-series interference analysis, and to perform a highly accurate time-series interference analysis. In other words, according to the information processing device of this embodiment, it is possible to appropriately leave valid image pairs from all the image pairs used in the time-series interference analysis, and to perform a more accurate time-series interference analysis.

[0030] ***Hardware Configuration Description*** FIG. 4 is a diagram showing an example of a hardware configuration of information processing device 100 according to the present embodiment.

[0031] The information processing device 100 is a computer. The information processing device 100 includes a processor 910 and other hardware such as a memory 921, an auxiliary storage device 922, an input / output interface 930, and a communication interface 950. The processor 910 is connected to the other hardware via signal lines and controls the other hardware.

[0032] As described above, the information processing device 100 includes, as functional elements, the image pair generation unit 110, the pair index value calculation unit 120, the selection unit 130, the time-series interference analysis unit 140, and the storage unit 150. The functions of the image pair generation unit 110, the pair index value calculation unit 120, the selection unit 130, and the time-series interference analysis unit 140 are realized by software. The storage unit 150 is realized by the memory 921 or the auxiliary storage device 922. In the following description, the image pair generation unit 110, the pair index value calculation unit 120, the selection unit 130, and the time-series interference analysis unit 140 may be referred to as each unit of the information processing device 100.

[0033] The processor 910 is a device that executes an information processing program. The information processing program is a program that realizes the functions of the information processing device 100. The processor 910 is an IC that performs arithmetic processing. Specific examples of the processor 910 are a CPU, a DSP, and a GPU. IC is an abbreviation for Integrated Circuit. CPU is an abbreviation for Central Processing Unit. DSP is an abbreviation for Digital Signal Processor. GPU is an abbreviation for Graphics Processing Unit.

[0034] The memory 921 is a storage device that temporarily stores data. Specific examples of the memory 921 are SRAM and DRAM. SRAM is an abbreviation for Static Random Access Memory. DRAM is an abbreviation for Dynamic Random Access Memory. The auxiliary storage device 922 is a storage device that stores data. A specific example of the auxiliary storage device 922 is a HDD. The auxiliary storage device 922 may also be a portable storage medium such as an SD (registered trademark) memory card, CF, NAND flash, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD. Note that HDD is an abbreviation for Hard Disk Drive. SD (registered trademark) is an abbreviation for Secure Digital. CF is an abbreviation for CompactFlash (registered trademark). DVD is an abbreviation for Digital Versatile Disk.

[0035] The input / output interface 930 is an interface for connecting an input / output device. Specific examples of the input / output interface 930 include a USB and an HDMI (registered trademark) port. USB is an abbreviation for Universal Serial Bus. HDMI (registered trademark) is an abbreviation for High-Definition Multimedia Interface.

[0036] The communication interface 950 is an interface for communicating with an external device. Specific examples of the communication interface 950 include an Ethernet (registered trademark) port, or a device for performing wireless communication.

[0037] The information processing program is executed in the information processing device 100. The information processing program is read into the processor 910 and executed by the processor 910. In addition to the information processing program, the OS is also stored in the memory 921. The OS is an abbreviation for Operating System. The processor 910 executes the information processing program while executing the OS. The information processing program and the OS may be stored in the auxiliary storage device 922. The information processing program and the OS stored in the auxiliary storage device 922 are loaded into the memory 921 and executed by the processor 910. Note that a part or all of the information processing program may be incorporated into the OS.

[0038] The information processing device 100 may include a plurality of processors that replace the processor 910. These plurality of processors share the task of executing the information processing program. Each of the processors is a device that executes the information processing program, similar to the processor 910.

[0039] Data, information, signal values ​​and variable values ​​used, processed or output by the information processing program are stored in the memory 921, the auxiliary storage device 922, or a register or cache memory within the processor 910.

[0040] The "part" of each part of information processing device 100 may be read as a "circuit," "step," "procedure," "process," or "circuitry." The information processing program causes a computer to execute each process, with the "part" of each part of information processing device 100 read as a "process." The "process" of each process of information processing device 100 may be read as a "program," "program product," "computer-readable storage medium storing a program," or "computer-readable recording medium recording a program." In addition, the information processing method is a method performed by information processing device 100 executing an information processing program. The information processing program may be provided in a state stored in a computer-readable recording medium, or as a program product.

[0041] FIG. 5 is a diagram showing another example of the hardware configuration of information processing device 100 according to the present embodiment. An example in which the functions of each unit of the information processing device 100 are realized by software has been described with reference to Fig. 4. On the other hand, an example in which the functions of each unit of the information processing device 100 are realized by hardware will be described with reference to Fig. 5. Specifically, the information processing device 100 includes an electronic circuit 909 instead of a processor 910 .

[0042] The electronic circuit 909 is a dedicated electronic circuit that realizes the functions of each unit of the information processing device 100. Specifically, the electronic circuit 909 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA, an ASIC, or an FPGA. GA is an abbreviation for Gate Array. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field-Programmable Gate Array.

[0043] The functions of each unit of the information processing device 100 may be realized by one electronic circuit, or may be distributed across multiple electronic circuits.

[0044] As another modification, some of the functions of each unit of the information processing device 100 may be realized by electronic circuits, and the remaining functions may be realized by software. Also, some or all of the functions of each unit of the information processing device 100 may be realized by firmware.

[0045] Each of the processor and the electronic circuit is also called a processing circuitry. That is, the functions of each unit of the information processing device 100 are realized by the processing circuitry.

[0046] Embodiment 2 In this embodiment, differences from and additions to the first embodiment will be mainly described. In this embodiment, components having the same functions as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0047] ***Configuration Description*** The configuration of information processing device 100 according to this embodiment is similar to that described in the first embodiment. In the specific example of the first embodiment, the standard deviation of an index such as the phase difference or coherence of an image pair is calculated as the pair index value 51. On the other hand, in the present embodiment, a specific example in which the most frequent value of an index is calculated as the pair index value 51 will be described.

[0048] ***Explanation of Operation*** FIG. 6 is a flow diagram showing an example of the operation of information processing device 100 according to the present embodiment. The process of step S101 is the same as in the first embodiment.

[0049] In step S102a, the pair index calculation unit 120 calculates the phase difference of each of the multiple image pairs as an index, and calculates the most frequent phase difference as the pair index value 51. In this embodiment, the threshold 151 is, for example, "0." The threshold 151 is set based on all pair index values ​​of a plurality of image pairs. The threshold 151 may be set to a value other than "0" based on all pair index values ​​of a plurality of image pairs.

[0050] In step S103a, the selection unit 130 excludes image pairs with a phase difference mode other than the threshold value "0" as inappropriate image pairs from the multiple image pairs 41. Image pairs with a phase difference mode other than "0" may have the effects of the atmosphere or ionosphere added to the entire image. Therefore, image pairs with a phase difference mode other than "0" are excluded because they are likely to contain noise components. The selection unit 130 removes inappropriate image pairs from the plurality of image pairs 41 and passes the remaining image pairs to the time-series interference analysis unit 140 as selected image pairs 61 .

[0051] The process in step S104 is the same as in the first embodiment.

[0052] ***Explanation of the Effects of the Present Embodiment*** As described above, the information processing device according to this embodiment analyzes the most frequent value of the phase difference of each image pair, and excludes image pairs whose most frequent value of the phase difference is not 0. As a result, the information processing device according to this embodiment can obtain the same effect as that of the first embodiment with a small amount of calculation.

[0053] Embodiment 3 In this embodiment, differences from the first and second embodiments and additional features to the first and second embodiments will be mainly described. In this embodiment, components having the same functions as those in the first and second embodiments are given the same reference numerals, and the description thereof will be omitted.

[0054] ***Configuration Description*** FIG. 7 is a diagram showing an example of a functional configuration of the information processing device 100 according to the present embodiment. The information processing device 100 according to this embodiment includes an intensity analysis unit 160 in addition to the functional configuration in Fig. 1. The storage unit 150 also includes an intensity threshold value 152 that is a threshold value of the standard deviation of the intensity. The intensity analysis unit 160 acquires a plurality of radar images and calculates the standard deviation of the intensity of each radar image. Then, the intensity analysis unit 160 uses the standard deviation of the intensity of each radar image and the intensity threshold 152 to remove inappropriate radar images from the plurality of radar images 31. The intensity analysis unit 160 passes the remaining radar images, after removing the inappropriate radar images from the plurality of radar images 31, to the image pair generation unit 110 as a plurality of radar images 31a.

[0055] ***Explanation of Operation*** FIG. 7 is a flow diagram showing an example of the operation of information processing device 100 according to the present embodiment. The processes from step S101 to step S104 are similar to those in embodiment 1. In this embodiment, a strength analysis process in step S100 is executed before step S101.

[0056] <Strength analysis processing> In step S100, the intensity analysis unit 160 acquires a plurality of radar images 31. The intensity analysis unit 160 calculates a standard deviation of the intensity of each radar image of the plurality of radar images 31. Using the standard deviation of the intensity of each radar image and the intensity threshold 152, the intensity analysis unit 160 removes radar images having an intensity standard deviation greater than the intensity threshold 152 as inappropriate radar images from the plurality of radar images 31. The intensity analysis unit 160 passes the remaining plurality of radar images 31a from which the inappropriate radar images have been removed to the image pair generation unit 110. A radar image with a large standard deviation of intensity may have stripe noise on the image due to the influence of the ionosphere, etc. For this reason, the intensity analysis unit 160 excludes radar images with a large standard deviation of intensity in advance, since they are not appropriate as radar images to be used in time-series interference analysis. It is assumed that the intensity threshold 152, which is the threshold of the standard deviation of the intensity, is set in advance by an administrator or the like.

[0057] In step S101, the image pair generation unit 110 acquires a plurality of radar images 31a from the intensity analysis unit 160, and generates a plurality of image pairs 41 to be used for time-series interference analysis from the plurality of radar images 31a. The image pair generation process is the same as that of the first embodiment, except that inappropriate radar images have already been removed from the plurality of radar images 31.

[0058] In the present embodiment, the strength analysis process of step S100 is added to the process of embodiment 1. On the other hand, the strength analysis process of step S100 may be added to the process of embodiment 2. In that case, in the flow diagram of FIG. 3, the strength analysis process of step S100 is executed before step S101.

[0059] ***Explanation of the Effects of the Present Embodiment*** As described above, the information processing device according to this embodiment excludes radar images with a large standard deviation of intensity in advance as radar images that are not appropriate for use in time-series interference analysis, thereby enabling the information processing device according to this embodiment to perform a more accurate time-series interference analysis.

[0060] In the above first to third embodiments, each unit of the information processing device has been described as an independent functional block. However, the configuration of the information processing device does not have to be as in the above-mentioned embodiments. The functional blocks of the information processing device may have any configuration as long as they can realize the functions described in the above-mentioned embodiments. Furthermore, the information processing device may not be a single device, but may be a system composed of multiple devices. In addition, it is acceptable to combine two or more parts of the first to third embodiments. Alternatively, it is acceptable to implement only one part of these embodiments. In addition, it is acceptable to combine these embodiments in any way, either as a whole or in part. That is, in the first to third embodiments, the embodiments can be freely combined, any of the components in each embodiment can be modified, or any of the components in each embodiment can be omitted.

[0061] The above-described embodiment is essentially a preferred example, and is not intended to limit the scope of the present disclosure, the scope of application of the present disclosure, and the scope of use of the present disclosure. The above-described embodiment can be modified in various ways as necessary. For example, the procedure described using a flow chart or sequence chart may be modified as appropriate.

[0062] Various aspects of the present disclosure are summarized below as appendices.

[0063] (Appendix 1) an image pair generation unit that generates a plurality of image pairs to be used for time-series interference analysis from a plurality of radar images observed at different times; a pair index value calculation unit that calculates an index representing a relationship between radar images included in each of the plurality of image pairs and calculates a pair index value used to determine whether or not it is appropriate to use the image pair in a time-series interference analysis by statistically analyzing the index; a selection unit that uses a threshold value that is set based on all pair index values ​​of the plurality of image pairs to exclude image pairs that are not appropriate as image pairs to be used in a time-series interference analysis from the plurality of image pairs; a time-series interference analysis unit that performs a time-series interference analysis using the remaining image pairs obtained by excluding the inappropriate image pairs from the plurality of image pairs; An information processing device comprising: (Appendix 2) The pair index value calculation unit 2. The information processing device according to claim 1, wherein the standard deviation of the index is calculated as the pair index value. (Appendix 3) 3. The information processing device according to claim 1, wherein the threshold is set based on a statistical distribution of all pair index values ​​of the plurality of image pairs. (Appendix 4) The pair index value calculation unit The information processing device according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the coherence of each image pair of the plurality of image pairs is calculated as the index. (Appendix 5) The pair index value calculation unit 5. The information processing device according to claim 1, further comprising: a phase difference between each of the plurality of image pairs calculated as the index. (Appendix 6) The pair index value calculation unit Calculating a phase difference between each image pair of the plurality of image pairs as the index, and calculating a mode of the phase differences as the pair index value; The selection unit is The information processing device according to claim 1, wherein the threshold value is set to 0, and image pairs having a phase difference mode other than 0 are excluded as the inappropriate image pairs. (Appendix 7) The information processing device further includes: an intensity analysis unit that calculates a standard deviation of an intensity of each of the plurality of radar images and removes the inappropriate radar image from the plurality of radar images using the standard deviation of the intensity; The image pair generation unit 7. The information processing device according to claim 1, further comprising: generating the plurality of image pairs from the plurality of radar images from which the inappropriate radar image has been excluded. (Appendix 8) 8. The information processing device according to claim 1, wherein each of the plurality of radar images is a Synthetic Aperture Radar (SAR) image. (Appendix 9) A computer generates a plurality of image pairs to be used for time-series interference analysis from a plurality of radar images observed at different times; a computer calculates an index representing a relationship between radar images included in each of the plurality of image pairs, and performs statistical analysis of the index to calculate a pair index value used to determine whether or not it is appropriate to use the image pair in a time-series interference analysis; a computer using a threshold value set based on all pair index values ​​of the plurality of image pairs to exclude image pairs that are not appropriate as image pairs to be used in the time-series interference analysis from the plurality of image pairs; An information processing method in which a computer performs a time-series interference analysis using the remaining image pairs after excluding the inappropriate image pairs from the plurality of image pairs. (Appendix 10) an image pair generation process for generating a plurality of image pairs to be used for time-series interference analysis from a plurality of radar images observed at different times; a pair index value calculation process for calculating an index representing a relationship between radar images included in each of the plurality of image pairs and calculating a pair index value used to determine whether or not it is appropriate to use the image pair in a time-series interference analysis by statistically analyzing the index; a selection process of excluding image pairs that are not appropriate as image pairs to be used in the time-series interference analysis from the plurality of image pairs using a threshold value set based on all pair index values ​​of the plurality of image pairs; a time-series interference analysis process for performing a time-series interference analysis using the remaining image pairs obtained by excluding the inappropriate image pairs from the plurality of image pairs; An information processing program that causes a computer to execute the above. [Explanation of symbols]

[0064] 31, 31a multiple radar images, 41 multiple image pairs, 51 pair index value, 61 selected image pair, 80 analysis result, 100 information processing device, 110 image pair generation unit, 120 pair index value calculation unit, 130 selection unit, 140 time series interference analysis unit, 150 memory unit, 151 threshold, 152 intensity threshold, 160 intensity analysis unit, 909 electronic circuit, 910 processor, 921 memory, 922 auxiliary storage device, 930 input / output interface, 950 communication interface.

Claims

1. an image pair generation unit that generates a plurality of image pairs to be used for time-series interference analysis from a plurality of radar images observed at different times; a pair index value calculation unit that calculates an index representing a relationship between radar images included in each of the plurality of image pairs and calculates a pair index value used to determine whether or not it is appropriate to use the image pair in a time-series interference analysis by statistically analyzing the index; a selection unit that uses a threshold value that is set based on all pair index values ​​of the plurality of image pairs to exclude image pairs that are not appropriate as image pairs to be used in a time-series interference analysis from the plurality of image pairs; a time-series interference analysis unit that performs a time-series interference analysis using the remaining image pairs obtained by excluding the inappropriate image pairs from the plurality of image pairs; An information processing device comprising:

2. The pair index value calculation unit The information processing apparatus according to claim 1 , wherein a standard deviation of the index is calculated as the pair index value.

3. The information processing apparatus according to claim 1 , wherein the threshold value is set based on a statistical distribution of all pair index values ​​of the plurality of image pairs.

4. The pair index value calculation unit The information processing apparatus according to claim 1 , wherein the coherence of each of the plurality of image pairs is calculated as the index.

5. The pair index value calculation unit The information processing apparatus according to claim 1 , wherein a phase difference between each of the plurality of image pairs is calculated as the index.

6. The pair index value calculation unit Calculating a phase difference between each image pair of the plurality of image pairs as the index, and calculating a mode of the phase differences as the pair index value; The selection unit is The information processing apparatus according to claim 1 , wherein the threshold value is set to 0, and image pairs having a phase difference mode other than 0 are excluded as the inappropriate image pairs.

7. The information processing device further includes: an intensity analysis unit that calculates a standard deviation of an intensity of each of the plurality of radar images and removes the inappropriate radar image from the plurality of radar images using the standard deviation of the intensity; The image pair generation unit The information processing apparatus according to claim 1 , wherein the plurality of image pairs are generated from the plurality of radar images from which the inappropriate radar images have been excluded.

8. The information processing device according to claim 1 or 2, wherein each of the plurality of radar images is a Synthetic Aperture Radar (SAR) image.

9. A computer generates a plurality of image pairs to be used for time-series interference analysis from a plurality of radar images observed at different times; a computer calculates an index representing a relationship between radar images included in each of the plurality of image pairs, and performs statistical analysis of the index to calculate a pair index value used to determine whether or not it is appropriate to use the image pair in a time-series interference analysis; a computer using a threshold value set based on all pair index values ​​of the plurality of image pairs to exclude image pairs that are not appropriate as image pairs to be used in the time-series interference analysis from the plurality of image pairs; An information processing method in which a computer performs a time-series interference analysis using the remaining image pairs after excluding the inappropriate image pairs from the plurality of image pairs.

10. an image pair generation process for generating a plurality of image pairs to be used for time-series interference analysis from a plurality of radar images observed at different times; a pair index value calculation process for calculating an index representing a relationship between radar images included in each of the plurality of image pairs and calculating a pair index value used to determine whether or not it is appropriate to use the image pair in a time-series interference analysis by statistically analyzing the index; a selection process of excluding image pairs that are not appropriate as image pairs to be used in the time-series interference analysis from the plurality of image pairs using a threshold value set based on all pair index values ​​of the plurality of image pairs; a time-series interference analysis process for performing a time-series interference analysis using the remaining image pairs obtained by excluding the inappropriate image pairs from the plurality of image pairs; An information processing program that causes a computer to execute the above.

Images