A method and device for solving the distance to the position of a scattering center

Abstract

The present invention relates to a method and device for solving the distance position of a scattering center. A specific implementation of the method includes: obtaining first scattering data and second scattering data of a target, thereby generating a first specific image and a second specific image; extracting initial parameters of multiple scattering centers from the first specific image; determining the pixel value of the corresponding position in the second specific image as the second complex amplitude of the scattering center based on the initial azimuth position data and initial distance position data of any scattering center extracted; using the first complex amplitude, the second complex amplitude and the initial distance position data of any scattering center to determine the distance fine-tuning data of the scattering center, and combining the distance fine-tuning data and the initial distance position data of the scattering center to obtain the accurate distance position data of the scattering center. This implementation can solve the problem that it is difficult to accurately estimate and extract the distance position parameters of the scattering center in the prior art.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic property technology, and in particular to a method and device for solving the distance position of a scattering center. Background Art

[0002] In the radar high frequency region, the total scattering field of an electrically large target can be regarded as a series of local position scattering fields, which are usually called scattering centers. The parameterized model of scattering centers can express the scattering characteristics of targets concisely and effectively, and has important applications in data compression and generation, radar target recognition and other fields.

[0003] For the application of target scattering characteristic data compression and generation, the accuracy of the distance position parameters in the scattering center model is particularly important. This is because the phase of the scattering field reconstructed by the scattering center is very sensitive to the distance position parameters of the scattering center (in the high-frequency region, due to the very high frequency of electromagnetic waves, a small position error of the scattering center will cause a huge change in the phase of the reconstructed scattering field), and the electromagnetic field is a coherent field. The phase error of the scattering field reconstructed by the scattering center will cause an erroneous coherent superposition relationship, resulting in a large error when multiple scattering centers synthesize the total scattering field of the target. Therefore, accurately estimating and extracting the distance position parameters of the scattering center is the basis for realizing this application.

[0004] At present, the data-based scattering center parameter extraction methods can be mainly divided into three categories: Fourier transform-based methods, super-resolution spectrum estimation methods, and iterative optimization methods. Among them, the Fourier transform-based method directly extracts the scattering center model parameters from the image domain, which can effectively reduce the complexity of the feature extraction problem and improve the efficiency of scattering center extraction, but the parameter extraction accuracy is limited by the image resolution; and although the super-resolution spectrum estimation method and iterative optimization method can improve the extraction accuracy of scattering center parameters, these two methods are relatively complex, with large computational complexity and low scattering center extraction efficiency. Summary of the invention

[0005] In view of the defects in the prior art, the present invention provides a method and device for solving the distance-to-position of a scattering center, which can solve the problem in the prior art that the distance-to-position parameters of the scattering center are difficult to accurately estimate and extract.

[0006] In order to solve the above technical problem, in one aspect, an embodiment of the present invention provides a method for solving the position of a scattering center distance.

[0007] The method for solving the distance position of a scattering center in an embodiment of the present invention includes: acquiring first scattering data and second scattering data of a target; generating a first specific image according to the first scattering data, and generating a second specific image according to the second scattering data; wherein the center frequencies of the first scattering data and the second scattering data are different; extracting initial parameters of multiple scattering centers from the first specific image; wherein the initial parameters of each scattering center include: first complex amplitude data, initial azimuth position data and initial distance position data of the scattering center; according to the initial azimuth position data and initial distance position data of any scattering center extracted from the first specific image, determining the pixel value of the corresponding position in the second specific image as the second complex amplitude data of the scattering center; using the first complex amplitude data, second complex amplitude data and initial distance position data of any scattering center to determine the distance fine-tuning data of the scattering center, and combining the distance fine-tuning data and the initial distance position data of the scattering center to obtain the precise distance position data of the scattering center.

[0008] Optionally, acquiring the first scattering data and the second scattering data of the target includes: setting an image resolution and an imaging range, and acquiring the first scattering data and the second scattering data by actual measurement or simulation calculation.

[0009] Optionally, the center frequency of the first scattered data and the center frequency of the second scattered data satisfy the following relationship:

[0010]

[0011] Where f1 is the center frequency of the first scattered data, f2 is the center frequency of the second scattered data, c represents the speed of light, y c Indicates the uncertainty range of the distance position.

[0012] Optionally, extracting the initial parameters of multiple scattering centers from the first specific image includes: determining the strongest pixel point in the first specific image as the first scattering center; determining the pixel value of the pixel point as the first complex amplitude data of the first scattering center, determining the azimuth position of the pixel point as the initial azimuth position data of the first scattering center, and determining the distance position of the pixel point as the initial distance position data of the first scattering center; reconstructing the scattering data according to the first complex amplitude data, initial azimuth position data and initial distance position data of the first scattering center, and generating a reconstructed image based on the reconstructed scattering data; subtracting the reconstructed image from the first specific image to generate a residual image; and finding the residual image The strongest pixel point in the image is determined, and when the pixel value of the pixel point is not less than a preset threshold value, the pixel point is determined as the second scattering center; the pixel value of the pixel point is determined as the first complex amplitude data of the second scattering center, the azimuth position of the pixel point is determined as the initial azimuth position data of the second scattering center, and the distance position of the pixel point is determined as the initial distance position data of the second scattering center; the steps of reconstructing the scattering data, generating a reconstructed image, generating a residual image, searching for the strongest pixel point, and comparing the strongest pixel point with the threshold value are repeatedly performed until the pixel value of the strongest pixel point in the generated residual image is less than the threshold value, thereby determining multiple scattering centers and the initial parameters of each scattering center.

[0013] Optionally, the determining the distance-direction fine-tuning data of any scattering center using the first complex amplitude data, the second complex amplitude data and the initial distance-direction position data of the scattering center comprises:

[0014] The distance fine-tuning data of any scattering center is calculated by the following formula:

[0015]

[0016] Among them, y p0 represents the distance fine-tuning data of the pth scattering center, where p is a positive integer; phase(g) represents the operation of solving the phase; A1 p ' represents the first complex amplitude data of the pth scattering center, A2 p ' represents the second complex amplitude data of the pth scattering center; k1 is the wave number corresponding to the center frequency of the first scattering data, k2 is the wave number corresponding to the center frequency of the second scattering data; y1 p Represents the initial distance position data of the pth scattering center.

[0017] Optionally, the combining the distance fine-tuning data and the initial distance position data of the scattering center to obtain the precise distance position data of the scattering center includes:

[0018] The initial distance position data of any scattering center is subtracted from the distance fine-tuning data of the scattering center to obtain the precise distance position data of the scattering center.

[0019] Optionally, the first specific image, the second specific image, the reconstructed image and the residual image are images of the same type; the type includes: synthetic aperture radar SAR image, inverse synthetic aperture radar ISAR image or one-dimensional range image; the uncertainty range of the range position is set to the size of the range resolution unit in the first specific image.

[0020] In order to solve the above technical problem, on the other hand, an embodiment of the present invention provides a device for solving the position of a scattering center distance.

[0021] The device for solving the distance position of a scattering center in an embodiment of the present invention may include: an image generating unit, used to: obtain first scattering data and second scattering data of a target; generate a first specific image according to the first scattering data, and generate a second specific image according to the second scattering data; wherein the center frequencies of the first scattering data and the second scattering data are different; a first parameter extracting unit, used to: extract initial parameters of multiple scattering centers from the first specific image; wherein the initial parameters of each scattering center include: first complex amplitude data, initial azimuth position data, and initial distance position data of the scattering center; a second parameter extracting unit, used to: determine the pixel value of the corresponding position in the second specific image as the second complex amplitude data of the scattering center based on the initial azimuth position data and initial distance position data of any scattering center extracted from the first specific image; a calculating unit, used to: determine the distance fine-tuning data of any scattering center using the first complex amplitude data, the second complex amplitude data, and the initial distance position data of the scattering center, and obtain the precise distance position data of the scattering center by combining the distance fine-tuning data and the initial distance position data of the scattering center.

[0022] To achieve the above objective, according to another aspect of the present invention, an electronic device is provided.

[0023] An electronic device of the present invention includes: one or more processors; a storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, the one or more processors implement the method for solving the scattering center distance to position provided by the present invention.

[0024] To achieve the above objective, according to yet another aspect of the present invention, a computer-readable storage medium is provided.

[0025] A computer-readable storage medium of the present invention stores a computer program, which, when executed by a processor, implements the method for solving the distance to the position of the scattering center provided by the present invention.

[0026] The method and device for solving the distance position of a scattering center of the present invention have the following beneficial effects: first, obtaining the first scattering data and the second scattering data of the target; generating a first specific image according to the first scattering data, and generating a second specific image according to the second scattering data; wherein the center frequencies of the first scattering data and the second scattering data are different; then, extracting the initial parameters of multiple scattering centers from the first specific image; wherein the initial parameters of each scattering center include: the first complex amplitude data, the initial azimuth position data and the initial distance position data of the scattering center; thereafter, according to the initial azimuth position data and the initial distance position data of any scattering center extracted from the first specific image, determining the pixel value of the corresponding position in the second specific image as the second complex amplitude data of the scattering center; finally, using the first complex amplitude data, the second complex amplitude data and the initial distance position data of any scattering center to determine the distance fine-tuning data of the scattering center, combining the distance fine-tuning data and the initial distance position data of the scattering center to obtain the accurate distance position data of the scattering center. In this way, under high signal-to-noise ratio conditions such as simulation or darkroom measurement, the above method can achieve efficient and accurate forward solution of the distance position of the scattering center, providing strong support for applications such as effective compression and rapid generation of target characteristic data based on scattering centers. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the main steps of the method for solving the distance to the position of the scattering center in an embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of the overall concept of the method for solving the distance to the position of the scattering center in an embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of a first specific image and a second specific image according to an embodiment of the present invention;

[0030] Figure 4 is a schematic diagram of initial parameter extraction of scattering centers according to an embodiment of the present invention;

[0031] Figure 5 It is a schematic diagram of components of a device for solving the distance to the position of a scattering center in an embodiment of the present invention;

[0032] Figure 6 It is a schematic diagram of the structure of an electronic device used to implement the method for solving the distance to the position of the scattering center in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Figure 1 Schematic diagram of main steps of the method for solving the distance to position of the scattering center according to an embodiment of the present invention.

[0035] like Figure 1 As shown, the method for solving the position of the scattering center distance in the embodiment of the present invention can be specifically performed according to the following steps:

[0036] Step S101: acquiring first scattering data and second scattering data of a target; generating a first specific image according to the first scattering data, and generating a second specific image according to the second scattering data.

[0037] In this step, two specific images with different center frequencies can be generated based on the scattering data of the target. The above specific images and the reconstructed images and residual images to be described later are all the same type of images; the above types may include: synthetic aperture radar SAR images, inverse synthetic aperture radar ISAR images or one-dimensional range images. The following mainly takes SAR images as an example for introduction.

[0038] In practical applications, the image resolution and imaging range can be set first, and then the target’s central angle at the synthetic aperture can be obtained through actual measurement or simulation calculation. In the following, there are two sets of scattered data with center frequencies f1 and f2 (the two are not equal): first scattered data and second scattered data.

[0039] In particular, to ensure the uniqueness of the subsequent distance-to-position solution, the two selected center frequencies f1 and f2 should satisfy the following relationship:

[0040]

[0041] Where c represents the speed of light; y c Indicates the uncertainty range of the range position, which can be set to the range resolution unit size in the SAR image (ie, the first specific image or the second specific image).

[0042] After the first scattering data and the second scattering data are obtained, an imaging algorithm may be used to image the first scattering data and the second scattering data to generate a first specific image and a second specific image, respectively.

[0043] Step S102: extracting initial parameters of multiple scattering centers from the first specific image; wherein the initial parameters of each scattering center include: first complex amplitude data, initial azimuth position data and initial range position data of the scattering center.

[0044] In this step, the CLEAN algorithm in image processing is used to extract the initial parameters of the target scattering center from the first specific image. Specifically, first, the strongest pixel in the first specific image is determined as the first scattering center; the pixel value of the pixel is determined as the first complex amplitude data of the first scattering center, the azimuth position of the pixel is determined as the initial azimuth position data of the first scattering center, and the distance position of the pixel is determined as the initial distance position data of the first scattering center.

[0045] Next, scattering data is reconstructed according to the first complex amplitude data of the first scattering center, the initial azimuth position data and the initial distance position data (the scattering data is wide-bandwidth angle scattering data, and the wide bandwidth and wide angle in this article can determine their accurate ranges according to actual needs), and a reconstructed image is generated based on the reconstructed scattering data; the reconstructed image is subtracted from the first specific image to generate a residual image.

[0046] Thereafter, the strongest pixel point in the residual image is found, and when the pixel value of the pixel point is not less than a preset threshold value, the pixel point is determined as the second scattering center; the pixel value of the pixel point is determined as the first complex amplitude data of the second scattering center, the azimuth position of the pixel point is determined as the initial azimuth position data of the second scattering center, and the distance position of the pixel point is determined as the initial distance position data of the second scattering center.

[0047] Afterwards, the steps of reconstructing the scattering data, generating a reconstructed image, generating a residual image, finding the strongest pixel point, and comparing the strongest pixel point with the threshold value are repeated until the pixel value of the strongest pixel point in the generated residual image is less than the threshold value, thereby determining multiple scattering centers and initial parameters of each scattering center.

[0048] After Q cycles of the above CLEAN algorithm, the initial parameters of Q scattering centers are finally extracted: SCM1' = [(A11', x11', y11'), ..., (A1 p ',x1 p ',y1 p '),...,(A1 Q ',x1 Q ',y1 Q ')]. Where p∈[1,Q] represents the number of the pth scattering center, A1 p ', x1 p ' and y1 p'represent the first complex amplitude data, initial azimuth position data and initial range position data of the pth scattering center respectively.

[0049] Step S103: according to the initial azimuth position data and the initial range position data of any scattering center extracted from the first specific image, the pixel value of the corresponding position in the second specific image is determined as the second complex amplitude data of the scattering center.

[0050] In this step, for the second specific image, according to the scattering center position (i.e., the initial azimuth position data and the initial range position data) extracted from the first specific image, the pixel value at the corresponding position in the second specific image is determined (the value is the second complex amplitude data of the scattering center): [A21',...,A2 p ',...,A2 Q '], A2 p ' represents the second complex amplitude data of the pth scattering center.

[0051] Step S104: Use the first complex amplitude data, the second complex amplitude data and the initial range position data of any scattering center to determine the range fine-tuning data of the scattering center, and combine the range fine-tuning data and the initial range position data of the scattering center to obtain the precise range position data of the scattering center.

[0052] In this step, the precise distance position parameters of the scattering center can be solved according to the difference between the complex amplitudes of the scattering center in the first specific image and the second specific image. The complex amplitude at a certain scattering center position in the SAR image is mainly contributed by the scattering center and is less affected by other scattering centers. Based on the above assumptions and the image domain expression of the scattering center, according to the initial parameters of the scattering center extracted in the previous step, the precise distance position data y of the pth scattering center can be obtained. p The following relationship should be satisfied:

[0053]

[0054] in represents the wave number corresponding to the two frequencies f1 and f2; y p represents the precise distance position of the scattering center; phase(g) represents the operation of solving the phase. The constraint relationship between the two frequencies in step S101 ensures the uniqueness of the solution of the above equation, so solving the above equation can obtain the distance fine-tuning data of the pth scattering center:

[0055]

[0056] Among them, y p0 Represents the distance fine-tuning data of the p-th scattering center, where p is a positive integer.

[0057] Thereafter, the distance fine-tuning data of any scattering center is subtracted from the initial distance position data of the scattering center to obtain the precise distance position data of the scattering center, that is:

[0058]

[0059] Figure 2 It is a schematic diagram of the overall concept of the method for solving the distance to position of the scattering center in an embodiment of the present invention, from which the technical concept of solving the distance to position of the scattering center of the present invention can be reflected.

[0060] A specific embodiment of the present invention is described below, and the embodiment performs the following steps:

[0061] 1. Data acquisition: Set the SAR image resolution to 0.1m and the imaging range to 5m. Use high-frequency electromagnetic calculation software to simulate and calculate two sets of wide-bandwidth angle scattering data of the target at a pitch angle of 45° and a central azimuth angle of 45°, with center frequencies of 8.5GHz and 10GHz respectively.

[0062] 2. SAR image generation: The filtered back projection imaging algorithm is used to perform SAR imaging on two sets of wide-bandwidth angular scattering data. Figure 3 The imaging results of two SAR images are given.

[0063] 3. Extraction of initial parameters of scattering centers: The complex amplitude and position parameters of the scattering centers in the first SAR image are extracted using the CLEAN algorithm, and the complex amplitude at the corresponding pixel position in the second SAR image is determined based on the extracted position. Figure 4 The initial parameter extraction results of the scattering center are given. Figure 3 and Figure 4 In the figure, the grayscale corresponding to different pixel values ​​is shown on the right side of the SAR image. Figure 4 In the figure, the dots in the SAR image are the two extracted scattering centers. The following table shows the initial parameters of the two extracted scattering centers, where the complex amplitude of image 1 is the first complex amplitude data, and the complex amplitude of image 2 is the second complex amplitude data.

[0064]

[0065] 4. Accurate solution of the distance position of the scattering center: For each scattering center, the two frequency parameters (8.5GHz and 10GHz) and the initial complex amplitude and position parameters of the scattering center extracted from the two SAR images are substituted into the accurate solution formula of the distance position, and finally the accurate distance position parameters of the scattering center are obtained. The final calculated accurate distance position data of the scattering center are shown in the following table:

[0066] Scattering center number Accurate distance position (m) 1 -1.4582 2 -0.6127

[0067] In summary, in the technical solution of the embodiment of the present invention, based on the target wide bandwidth angle scattering characteristic data, two SAR images with poor resolutions and different center frequencies are used to realize the super-resolution accurate forward solution of the distance position of the scattering center. The whole process is simple and efficient, and the distance position of the scattering center obtained by the solution is highly accurate, which can effectively describe the coupling phase relationship between the scattering centers of the target, and can provide strong support for applications such as effective compression and rapid generation of target characteristic data based on scattering centers.

[0068] It should be noted that, for the convenience of description, the aforementioned method embodiments are described as a series of action combinations, but those skilled in the art should be aware that the present invention is not limited by the described action sequence, and some steps can actually be performed in other sequences or simultaneously. In addition, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily necessary to implement the present invention.

[0069] In order to better implement the above-mentioned solution of the embodiment of the present invention, relevant devices for implementing the above-mentioned solution are also provided below.

[0070] See also Figure 5 As shown, the scattering center distance position solving device 500 provided in the embodiment of the present invention may include: an image generating unit 501, a first parameter extracting unit 502, a second parameter extracting unit 503 and a calculating unit 504.

[0071] The image generation unit 501 may be used to: obtain first scattering data and second scattering data of the target; generate a first specific image according to the first scattering data, and generate a second specific image according to the second scattering data; wherein the center frequencies of the first scattering data and the second scattering data are different; the first parameter extraction unit 502 may be used to: extract initial parameters of multiple scattering centers from the first specific image; wherein the initial parameters of each scattering center include: first complex amplitude data, initial azimuth position data, and initial distance position data of the scattering center; the second parameter extraction unit 503 may be used to: determine the pixel value of the corresponding position in the second specific image as the second complex amplitude data of the scattering center based on the initial azimuth position data and initial distance position data of any scattering center extracted from the first specific image; the calculation unit 504 may be used to: determine the distance fine-tuning data of any scattering center using the first complex amplitude data, the second complex amplitude data, and the initial distance position data of the scattering center, and obtain the precise distance position data of the scattering center by combining the distance fine-tuning data and the initial distance position data of the scattering center.

[0072] In the embodiment of the present invention, the image generating unit 501 may be further used to: set the image resolution and the imaging range, and obtain the first scattering data and the second scattering data through actual measurement or simulation calculation.

[0073] As a preferred solution, the center frequency of the first scattered data and the center frequency of the second scattered data satisfy the following relationship:

[0074]

[0075] Where f1 is the center frequency of the first scattered data, f2 is the center frequency of the second scattered data, c represents the speed of light, y c Indicates the uncertainty range of the distance position.

[0076] Preferably, the first parameter extraction unit 502 can be further used to: determine the strongest pixel point in the first specific image as the first scattering center; determine the pixel value of the pixel point as the first complex amplitude data of the first scattering center, determine the azimuth position of the pixel point as the initial azimuth position data of the first scattering center, and determine the distance position of the pixel point as the initial distance position data of the first scattering center; reconstruct the scattering data according to the first complex amplitude data, the initial azimuth position data and the initial distance position data of the first scattering center, and generate a reconstructed image based on the reconstructed scattering data; subtract the reconstructed image from the first specific image to generate a residual image; find the strongest pixel in the residual image A pixel point, when the pixel value of the pixel point is not less than a preset threshold value, the pixel point is determined as a second scattering center; the pixel value of the pixel point is determined as the first complex amplitude data of the second scattering center, the azimuth position of the pixel point is determined as the initial azimuth position data of the second scattering center, and the distance position of the pixel point is determined as the initial distance position data of the second scattering center; and the steps of reconstructing the scattering data, generating a reconstructed image, generating a residual image, finding the strongest pixel point, and comparing the strongest pixel point with the threshold value are repeatedly performed until the pixel value of the strongest pixel point in the generated residual image is less than the threshold value, thereby determining multiple scattering centers and the initial parameters of each scattering center.

[0077] In a specific application, the calculation unit 504 may be further used to calculate the distance fine-tuning data of any scattering center by using the following formula:

[0078]

[0079] Among them, y p0 represents the distance fine-tuning data of the pth scattering center, where p is a positive integer; phase(g) represents the operation of solving the phase; A1 p ' represents the first complex amplitude data of the pth scattering center, A2 p' represents the second complex amplitude data of the pth scattering center; k1 is the wave number corresponding to the center frequency of the first scattering data, k2 is the wave number corresponding to the center frequency of the second scattering data; y1 p Represents the initial distance position data of the pth scattering center.

[0080] In practical applications, the calculation unit 504 may be further configured to: subtract the distance fine-tuning data of any scattering center from the initial distance position data of the scattering center to obtain the precise distance position data of the scattering center.

[0081] In addition, in an embodiment of the present invention, the first specific image, the second specific image, the reconstructed image and the residual image are images of the same type; the type includes: synthetic aperture radar SAR image, inverse synthetic aperture radar ISAR image or one-dimensional range image; the uncertainty range of the range position is set to the size of the range resolution unit in the first specific image.

[0082] In the technical solution of the embodiment of the present invention, based on the target wide bandwidth angle scattering characteristic data, two SAR images with poor resolutions and different center frequencies are used to realize the super-resolution accurate forward solution of the distance position of the scattering center. The whole process is simple and efficient, the distance position of the scattering center obtained is highly accurate, and the coupling phase relationship between the scattering centers of the target can be effectively described, which can provide strong support for applications such as effective compression and rapid generation of target characteristic data based on scattering centers.

[0083] The present invention also provides an electronic device. The electronic device of an embodiment of the present invention includes: one or more processors; a storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, the one or more processors implement the scattering center distance position solution method provided by the present invention.

[0084] Reference below Figure 6 , which shows a schematic diagram of the structure of a computer system 600 of an electronic device suitable for implementing an embodiment of the present invention. Figure 6 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0085] like Figure 6As shown, the computer system 600 includes a central processing unit (CPU) 601, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage part 608 into a random access memory (RAM) 603. In the RAM 603, various programs and data required for the operation of the computer system 600 are also stored. The CPU 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0086] The following components are connected to the I / O interface 605: an input section 606 including a keyboard, a mouse, etc.; an output section 607 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 608 including a hard disk, etc.; and a communication section 609 including a network interface card such as a LAN card, a modem, etc. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to the I / O interface 605 as needed. A removable medium 611, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 610 as needed so that a computer program read therefrom is installed into the storage section 608 as needed.

[0087] In particular, according to the embodiments disclosed in the present invention, the process described in the main step diagram above can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the main step diagram. In the above embodiment, the computer program can be downloaded and installed from the network through the communication part 609, and / or installed from the removable medium 611. When the computer program is executed by the central processing unit 601, the above functions defined in the system of the present invention are executed.

[0088] It should be noted that the computer-readable medium shown in the present invention may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present invention, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer readable signal media may also be any computer readable medium other than computer readable storage media, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0089] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the above-mentioned module, program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0090] The units involved in the embodiments of the present invention may be implemented by software or hardware. The units described may also be arranged in a processor, for example, may be described as: a processor includes an image generation unit, a first parameter extraction unit, a second parameter extraction unit and a calculation unit. The names of these units do not constitute a limitation on the units themselves in some cases, for example, the image generation unit may also be described as a "unit that provides a first specific image to the first parameter extraction unit".

[0091] As another aspect, the present invention further provides a computer-readable medium, which may be included in the device described in the above embodiment; or may exist independently without being assembled into the device. The computer-readable medium carries one or more programs. When the one or more programs are executed by the device, the steps executed by the device include: acquiring first scattering data and second scattering data of the target; generating a first specific image according to the first scattering data, and generating a second specific image according to the second scattering data; wherein the center frequencies of the first scattering data and the second scattering data are different; extracting initial parameters of multiple scattering centers from the first specific image; wherein the initial parameters of each scattering center include: first complex amplitude data, initial azimuth position data and initial range position data of the scattering center; according to the initial azimuth position data and initial range position data of any scattering center extracted from the first specific image, determining the pixel value of the corresponding position in the second specific image as the second complex amplitude data of the scattering center; using the first complex amplitude data, the second complex amplitude data and the initial range position data of any scattering center to determine the range fine-tuning data of the scattering center, and combining the range fine-tuning data and the initial range position data of the scattering center to obtain the precise range position data of the scattering center.

[0092] According to the technical solution of the embodiment of the present invention, the problem that the distance position parameters of the scattering center are difficult to accurately estimate and extract in the prior art is solved. In the embodiment of the present invention, for the wide bandwidth angle scattering data of the target, two SAR images with different center frequencies are first generated, and then the complex amplitude and position parameters of the scattering center in one of the images are extracted by using the CLEAN algorithm, and the complex amplitude parameters of the scattering center in the other image are determined according to the extracted position information, and finally the precise value of the distance position of the scattering center is forward solved according to the difference in the complex amplitude of the scattering center in the two images. The present invention can realize the accurate and rapid solution of the distance position of the scattering center by using only two SAR images with poor resolution, and can provide strong support for applications such as effective compression and rapid generation of target characteristic data based on scattering centers.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for solving the distance to the position of a scattering center, characterized in that: include: Acquire first scattering data and second scattering data of the target; Generate a first specific image according to the first scattering data, and generate a second specific image according to the second scattering data; wherein the center frequencies of the first scattering data and the second scattering data are different; Extracting initial parameters of multiple scattering centers from the first specific image; wherein the initial parameters of each scattering center include: first complex amplitude data, initial azimuth position data and initial range position data of the scattering center; According to the initial azimuth position data and the initial range position data of any scattering center extracted from the first specific image, the pixel value of the corresponding position in the second specific image is determined as the second complex amplitude data of the scattering center; Determine the distance-direction fine-tuning data of any scattering center using the first complex amplitude data, the second complex amplitude data and the initial distance-direction position data of the scattering center, and obtain the accurate distance-direction position data of the scattering center by combining the distance-direction fine-tuning data and the initial distance-direction position data of the scattering center; The method of using the first complex amplitude data, the second complex amplitude data and the initial distance position data of any scattering center to determine the distance fine-tuning data of the scattering center comprises: The distance fine-tuning data of any scattering center is calculated by the following formula: in, Represents the distance fine-tuning data of the pth scattering center, where p is a positive integer; represents the operation of solving the phase; represents the first complex amplitude data of the pth scattering center, represents the second complex amplitude data of the pth scattering center; k1 is the wave number corresponding to the center frequency of the first scattering data, and k2 is the wave number corresponding to the center frequency of the second scattering data; Represents the initial distance position data of the pth scattering center; The step of combining the distance fine-tuning data and the initial distance position data of the scattering center to obtain the accurate distance position data of the scattering center includes: The initial distance position data of any scattering center is subtracted from the distance fine-tuning data of the scattering center to obtain the precise distance position data of the scattering center.

2. The method according to claim 1, characterized in that The acquiring first scattering data and second scattering data of the target comprises: The image resolution and imaging range are set, and the first scattering data and the second scattering data are acquired through actual measurement or simulation calculation.

3. The method according to claim 1, characterized in that: The central frequency of the first scattered data and the central frequency of the second scattered data satisfy the following relationship: in, is the center frequency of the first scattering data, is the center frequency of the second scattering data, represents the speed of light, Indicates the uncertainty range of the distance position.

4. The method according to claim 3, characterized in that The step of extracting initial parameters of a plurality of scattering centers from the first specific image comprises: The strongest pixel in the first specific image is determined as the first scattering center; the pixel value of the pixel is determined as the first complex amplitude data of the first scattering center, the azimuth position of the pixel is determined as the initial azimuth position data of the first scattering center, and the distance position of the pixel is determined as the initial distance position data of the first scattering center; reconstructing scattering data according to first complex amplitude data of the first scattering center, initial azimuth position data and initial range position data, and generating a reconstructed image based on the reconstructed scattering data; and subtracting the reconstructed image from the first specific image to generate a residual image; Find the strongest pixel point in the residual image, and when the pixel value of the pixel point is not less than a preset threshold value, determine the pixel point as the second scattering center; determine the pixel value of the pixel point as the first complex amplitude data of the second scattering center, determine the azimuth position of the pixel point as the initial azimuth position data of the second scattering center, and determine the distance position of the pixel point as the initial distance position data of the second scattering center; The steps of reconstructing scattering data, generating a reconstructed image, generating a residual image, finding the strongest pixel point, and comparing the strongest pixel point with the threshold value are repeatedly performed until the pixel value of the strongest pixel point in the generated residual image is less than the threshold value, thereby determining multiple scattering centers and initial parameters of each scattering center.

5. The method according to claim 4, characterized in that The first specific image, the second specific image, the reconstructed image and the residual image are images of the same type; the type includes: synthetic aperture radar SAR image, inverse synthetic aperture radar ISAR image or one-dimensional range image; The uncertainty range of the range position is set to the size of the range resolution unit in the first specific image.

6. A device for solving the distance position of a scattering center, characterized in that: include: An image generating unit is used to: acquire first scattering data and second scattering data of a target; Generate a first specific image according to the first scattering data, and generate a second specific image according to the second scattering data; wherein the center frequencies of the first scattering data and the second scattering data are different; A first parameter extraction unit is used to extract initial parameters of multiple scattering centers from the first specific image; wherein the initial parameters of each scattering center include first complex amplitude data, initial azimuth position data and initial range position data of the scattering center; A second parameter extraction unit is used to: determine the pixel value of the corresponding position in the second specific image as the second complex amplitude data of the scattering center according to the initial azimuth position data and the initial distance position data of any scattering center extracted from the first specific image; A calculation unit, used to: determine the distance fine-tuning data of any scattering center using the first complex amplitude data, the second complex amplitude data and the initial distance position data of the scattering center, and obtain the accurate distance position data of the scattering center by combining the distance fine-tuning data and the initial distance position data of the scattering center; The method of using the first complex amplitude data, the second complex amplitude data and the initial distance position data of any scattering center to determine the distance fine-tuning data of the scattering center comprises: The distance fine-tuning data of any scattering center is calculated by the following formula: in, Represents the distance fine-tuning data of the pth scattering center, where p is a positive integer; represents the operation of solving the phase; represents the first complex amplitude data of the pth scattering center, represents the second complex amplitude data of the pth scattering center; k1 is the wave number corresponding to the center frequency of the first scattering data, and k2 is the wave number corresponding to the center frequency of the second scattering data; Represents the initial distance position data of the pth scattering center; The step of combining the distance fine-tuning data and the initial distance position data of the scattering center to obtain the accurate distance position data of the scattering center includes: The initial distance position data of any scattering center is subtracted from the distance fine-tuning data of the scattering center to obtain the precise distance position data of the scattering center.

7. An electronic device, characterized in that: include: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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