Radar imaging focusing method, device, computing device and storage medium

Abstract

The present invention provides a radar imaging focusing method, device, computing equipment and storage medium, the method comprising: obtaining echo data and motion data of a target radar; performing radar imaging according to the echo data and motion data to obtain an initial image; dividing the initial image into at least two sub-images according to at least two pre-set calibrators; wherein each sub-image corresponds to a calibrator; calculating the phase error of the sub-image according to the calibrator and its corresponding sub-image; performing error compensation on the sub-image according to the phase error to obtain a focused sub-image; splicing the focused sub-images to obtain a target radar image. The radar imaging focusing method provided by the scheme can improve the image focusing effect and the imaging quality of the radar image.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of radar imaging technology, and in particular to a radar imaging focusing method, device, computing device and storage medium. Background Art

[0002] In recent years, near-field radar imaging technology has gradually become a hot research topic in the radar field. It belongs to the field of active radar detection and has important application backgrounds in the civil and military fields, such as airport security, non-destructive testing, medical diagnosis, security screening, aerial imaging, military reconnaissance, vehicle-mounted platform warning, etc. After a long period of development, near-field radar imaging technology has made great breakthroughs in array structure, imaging algorithm and other directions.

[0003] With the commissioning of stealth equipment, the diagnosis and evaluation of stealth performance of equipment by radar near-field measurement in the maintenance field environment has attracted more and more attention. This method generally uses a two-dimensional plane scanning frame to obtain a two-dimensional scattering center distribution image at a specific attitude angle of the equipment. Compared with the traditional near-field measurement method, the near-field radar scanning measurement system based on the unmanned aerial platform is not limited by the hardware conditions such as the lack of turntable / guide rails and low-scattering metal brackets in the test site. It has the advantages of strong mobility and low cost in the scattering characteristics test of full-size targets. However, when the SAR mode of the unmanned aerial vehicle radar platform moving around the target is directly used for testing, the image directly imaged will produce defocusing due to the limitation of the motion accuracy of the platform flight trajectory; and the higher the resolution of the imaging, the more serious the impact of motion error. When the motion error reaches the wavelength level, it will seriously affect the quality of the radar image. Summary of the invention

[0004] The embodiments of the present invention provide a radar imaging focusing method, apparatus, computing device and storage medium, which improve the image focusing effect, thereby improving the imaging quality of the radar image, and do not require a high-precision motion sensor, further reducing the system cost.

[0005] In a first aspect, an embodiment of the present invention provides a radar imaging focusing method, comprising:

[0006] Obtain target radar echo data and motion data;

[0007] Perform radar imaging according to the echo data and the motion data to obtain an initial image;

[0008] According to at least two preset calibrators, the initial image is divided into at least two sub-images; wherein each of the sub-images corresponds to a calibrator;

[0009] According to the predetermined track of the target radar, the calibrator and the corresponding sub-image, a phase error of the sub-image is calculated;

[0010] Performing error compensation on the sub-image according to the phase error to obtain a focused sub-image;

[0011] The focused sub-images are stitched together to obtain a target radar image.

[0012] Optionally, performing radar imaging according to the echo data and the motion data to obtain an initial image includes:

[0013] performing phase compensation on the echo data according to the predetermined trajectory and the motion data to obtain compensated echo data;

[0014] The compensated echo data is used to perform radar imaging to obtain an initial image.

[0015] Optionally, the number of the calibrators is the same as the number of the sub-images.

[0016] Optionally, the initial image is equally divided into at least 2 sub-images.

[0017] Optionally, the calibrators are evenly distributed around the target object to be measured.

[0018] Optionally, the calculating the phase error of the sub-image according to the predetermined track of the target radar, the calibrator and the corresponding sub-image includes:

[0019] For each sub-image, execute:

[0020] extracting a complex image corresponding to the calibrator from the sub-image;

[0021] Performing echo reconstruction on the complex image to obtain first reconstructed echo data of the calibrator;

[0022] Determining the ideal point position of the calibrator according to the position of the calibrator in the sub-image, the motion data and the predetermined trajectory of the target radar;

[0023] Acquire second reconstructed echo data corresponding to the calibrator at the ideal point position;

[0024] A phase error is obtained according to the first reconstructed echo data and the second reconstructed echo data. Optionally, the first reconstructed echo data is determined by the following formula:

[0025] S r (θ, K) = ∫∫ xy g ε (x, y)·exp(-j2KR xy (θ))dxdy

[0026] Among them, S r(θ, K) is used to characterize the first reconstructed echo data; g ε (x, y) is used to represent the complex image, wherein (x, y) is used to represent the pixel coordinates in the complex image; R xy (θ) is used to characterize the distance from the pixel point in the complex image to the target radar; K is used to characterize the range wave number;

[0027] The second reconstructed echo data is determined by the following formula:

[0028] H A (θ, K) = exp(-j2KR Ae (θ)

[0029] Among them, H A (θ, K) is used to characterize the second reconstructed echo data; R Ae (θ) is used to characterize the distance from the ideal point position to the predetermined trajectory of the target radar; K is used to characterize the range wave number.

[0030] Optionally, the phase error is determined by the following formula:

[0031]

[0032] in, Used to characterize the phase error; S r (θ, K) is used to characterize the first reconstructed echo data; H A (θ, K) is used to characterize the second reconstructed echo data; * represents conjugation; K is used to characterize the range wave number.

[0033] Optionally, performing error compensation on the sub-image according to the phase error to obtain a focused sub-image includes:

[0034] For each sub-image, execute:

[0035] Acquire the echo data and phase error corresponding to the sub-image;

[0036] Conjugate multiplying the echo data with the phase error to obtain target echo data;

[0037] Imaging is performed according to the target echo data to obtain a focused sub-image.

[0038] Optionally, the imaging adopts a filtering-back projection algorithm.

[0039] Optionally, the target echo data is determined by the following formula:

[0040]

[0041] Among them, S1 (θ, K) is used to characterize the target echo data; S 0 (θ, K) is used to characterize the echo data; It is used to characterize the phase error; K is used to characterize the range wave number.

[0042] In a second aspect, an embodiment of the present invention further provides a radar imaging focusing device, comprising:

[0043] An acquisition module is used to acquire the echo data and motion data of the target radar;

[0044] A first imaging module, used for performing radar imaging according to the echo data and the motion data to obtain an initial image;

[0045] A division module, used for dividing the initial image into at least two sub-images according to at least two preset calibrators; wherein each of the sub-images corresponds to one calibrator;

[0046] A processing module, used for calculating the phase error of the sub-image according to the predetermined track of the target radar, the calibrator and the corresponding sub-image;

[0047] A second imaging module, used for performing error compensation on the sub-image according to the phase error to obtain a focused sub-image;

[0048] The stitching module is used to stitch the focused sub-images to obtain a target radar image.

[0049] In a third aspect, an embodiment of the present invention further provides a computing device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the radar imaging focusing method described in any one of the above items is implemented.

[0050] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to execute any of the above-mentioned radar imaging focusing methods.

[0051] The embodiment of the present invention provides a radar imaging focusing method, device, computing device and storage medium. The method pre-places multiple calibrators in the imaging scene, uses the motion data of the target radar motion sensor and the echo data in the imaging scene received by the target radar motion sensor to perform coarse imaging to obtain an initial image; then the initial image is divided according to the calibrator, and imaging focusing processing is performed on each sub-image respectively. The calculated phase error is added to the original echo data of the sub-image to achieve focusing of all sub-images, and finally a complete target radar image with good imaging quality is obtained by splicing. The present invention provides a radar imaging focusing method based on sub-image division, which does not require a high-precision motion sensor, improves the radar imaging focusing efficiency, simplifies the algorithm, further improves the image focusing effect, improves the imaging quality, and reduces the system cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 is a flow chart of a radar imaging focusing method provided by one embodiment of the present invention;

[0054] Figure 2 is a flow chart of another radar imaging focusing method provided by one embodiment of the present invention;

[0055] Figure 3 It is a schematic diagram of a geometric model for data acquisition of a SAR system based on an unmanned aerial vehicle radar platform provided by an embodiment of the present invention;

[0056] Figure 4 is a schematic diagram of dividing an initial image provided by an embodiment of the present invention;

[0057] Figure 5 is a hardware architecture diagram of a computing device provided by an embodiment of the present invention;

[0058] Figure 6 It is a structural diagram of a radar imaging focusing device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0060] Please refer to Figure 1 , an embodiment of the present invention provides a radar imaging focusing method, the method comprising:

[0061] Step 100, acquiring echo data and motion data of the target radar;

[0062] Step 102, performing radar imaging according to the echo data and the motion data to obtain an initial image;

[0063] Step 104, dividing the initial image into at least two sub-images according to at least two preset calibrators; wherein each sub-image corresponds to one calibrator;

[0064] Step 106, calculating the phase error of the sub-image according to the predetermined trajectory of the target radar, the calibrator and the corresponding sub-image;

[0065] Step 108, performing error compensation on the sub-image according to the phase error to obtain a focused sub-image;

[0066] Step 110: stitching the focused sub-images to obtain a target radar image.

[0067] It should be noted that the target radar can be a drone-mounted radar platform.

[0068] In the embodiment of the present invention, a plurality of calibrators are placed in advance in the imaging scene, and rough imaging is performed using the motion data of the target radar motion sensor and the echo data in the imaging scene received by the target radar motion sensor to obtain an initial image; then the initial image is divided according to the calibrator, and imaging focusing processing is performed on each sub-image respectively, and the calculated phase errors are added to the original echoes of the sub-images respectively to achieve focusing of all sub-images, and finally a complete target radar image with good imaging quality is obtained by splicing. The present invention provides a radar imaging focusing method based on sub-image division, which improves the radar imaging focusing efficiency, simplifies the algorithm, further improves the image focusing effect, and improves the imaging quality.

[0069] Described below Figure 1 How the various steps are performed.

[0070] First, for step 100, the echo data and motion data of the target radar are obtained, specifically, the motion data of the target radar in the imaging scene and the original echo data of the imaging scene received by the target radar are obtained. The imaging scene includes a target object and at least two calibrators.

[0071] With respect to step 102, radar imaging is performed according to the echo data and the motion data to obtain an initial image, including:

[0072] Performing phase compensation on the echo data according to the predetermined trajectory and motion data to obtain compensated echo data;

[0073] The compensated echo data is used for radar imaging to obtain an initial image.

[0074] In the present invention, since the uncertainty of the target radar platform movement causes motion error, thereby generating echo data phase error, error analysis and motion compensation for the unmanned aerial vehicle SAR platform movement are the key to obtaining high-quality SAR images. In step 102, the motion data measured by the motion sensor of the target radar and the original radar echo data both contain information about the motion trajectory of the target radar platform. By analyzing and processing the two, the phase error caused by the residual motion error can be estimated, and it can be compensated to the echo data obtained in step 100 to obtain compensated echo data, thereby reducing motion error, improving imaging quality, achieving image focusing, and obtaining an initial image.

[0075] In the present invention, the influence of residual motion error is eliminated by phase compensation. Therefore, the radar imaging focusing method provided by the present invention does not require a high-precision motion sensor, which not only reduces the system cost and improves the imaging quality, but also the imaging quality is no longer limited by the accuracy of the motion sensor.

[0076] In step 104, the number of scalers is the same as the number of sub-images.

[0077] Specifically, for example, the number of sub-images may be 4, 5, 6, 8, etc. The more calibrators there are, the more sub-images there are, and the more refined the division of the initial image is, so that the phase error corresponding to the sub-image is more accurate, and the imaging quality is higher.

[0078] In step 104, the initial image is equally divided into at least two sub-images.

[0079] In step 104, the calibrators are evenly distributed around the target object to be measured.

[0080] It should be noted that when the initial image is divided into a number of sub-images, the target object in the imaging scene is also divided into a number of sub-images.

[0081] With respect to step 106, the phase error of the sub-image is calculated based on the predetermined trajectory of the target radar, the calibrator and the corresponding sub-image, including:

[0082] For each sub-image, execute:

[0083] extracting a complex image corresponding to the calibrator from the sub-image;

[0084] Performing echo reconstruction on the complex image to obtain first reconstructed echo data of the calibrator;

[0085] Determining an ideal point position of the calibrator according to the position of the calibrator in the sub-image, the motion data and the predetermined trajectory of the target radar;

[0086] Acquire second reconstructed echo data corresponding to the calibrator at the ideal point position;

[0087] A phase error is obtained according to the first reconstructed echo data and the second reconstructed echo data.

[0088] In the present invention, the calibrator image in each sub-image is windowed and extracted to reduce the interference of clutter, and the echo is reconstructed. The reconstructed echo data of each calibrator is compared with the ideal echo signal data (i.e., the second reconstructed echo data) to obtain the phase error in the entire wave number domain K, which corresponds to the phase error compensation function of each sub-image. In the present invention, the method does not rely on the calibrator echo to have a high signal-to-clutter ratio. The separation of the echo signal and the clutter is achieved by windowing in the image domain, and the estimation accuracy of the phase error is improved, thereby further improving the final radar imaging quality.

[0089] Specifically, in step 106, the calculation formula of the first reconstructed echo data is as follows:

[0090] S r (θ, K) = ∫∫ xy g ε (x, y)·exp(-j2KR xy (θ))dxdy (1)

[0092] The calculation formula of the second reconstructed echo data is as follows:

[0093] H A (θ,K)=exp(-j2KR Ae (θ) (2)

[0095] The phase error is calculated as follows:

[0096]

[0097] Among them, Sr (θ, K) is used to characterize the first reconstructed echo data; g ε (x, y) is used to represent the complex image, where (x, y) is used to represent the pixel coordinates in the complex image; R xy (θ) is used to represent the distance from the pixel point in the complex image to the target radar; K is used to represent the range wave number; H A (θ, K) is used to characterize the second reconstructed echo data; R Ae (θ) is used to characterize the distance from the ideal point position to the predetermined trajectory of the target radar; Used to characterize phase error; * indicates conjugate; j is the unit of imaginary part.

[0098] Then, for step 108, error compensation is performed on the sub-image according to the phase error to obtain a focused sub-image, including:

[0099] For each sub-image, execute:

[0100] Acquire the echo data and phase error corresponding to the sub-image;

[0101] Conjugate multiplying the echo data with the phase error to obtain target echo data;

[0102] Imaging is performed according to the target echo data to obtain a focused sub-image.

[0103] In a preferred embodiment, the imaging is performed using a filter-backprojection algorithm.

[0104] In step 108, the target echo data is calculated as follows:

[0105]

[0106] Among them, S 1 (θ, K) is used to characterize the target echo data; S 0 (θ, K) is used to characterize the echo data of the target radar; Used to characterize phase error; K is used to characterize the range wave number.

[0107] It should be noted that in formulas (1) to (4), θ is used to represent the observation angle; for example, S 1 (θ, K) is the target echo data at the observation angle θ and the observation frequency K.

[0108] In the present invention, error compensation is the echo data S of the corresponding sub-image obtained in advance in step 100. 0 (θ, K), and the phase error of the sub-image Conjugate multiplication is used as the target echo data S for the sub-image imaging process. 1(θ, K), which can further eliminate the influence of residual motion errors, and then directly use the imaging algorithm to obtain the focused sub-image.

[0109] Finally, in step 110, the focused sub-image corresponding to each sub-image is processed using an image stitching algorithm to obtain a complete target radar image.

[0110] In the present invention, a SAR image focusing method based on a motion sensor and a SAR image focusing method based on echo data are combined to further enhance the image focusing effect of the algorithm and improve the imaging quality.

[0111] In order to more clearly illustrate the technical solutions and advantages of the present invention, Figure 2 As shown, a radar imaging focusing method provided by an embodiment of the present invention is described in detail below, specifically including:

[0112] Step 200: Acquire the echo data, motion data and predetermined trajectory of the target radar.

[0113] Specifically, the target radar is a drone-mounted radar platform, and the imaging scene includes a target and four calibrators (calibration body A, calibration body B, calibration body C, and calibration body D).

[0114] Step 201: Perform radar imaging according to the echo data and motion data to obtain an initial image.

[0115] Specifically, Figure 3 The schematic diagram of the geometric model of SAR system data acquisition based on the unmanned aerial vehicle radar platform is shown in the figure, P (x0, y0, 0) is a point target, A (x, y, z) is the ideal position of the unmanned aerial vehicle radar platform, A1 (x1, y1, z1) is the actual position of the unmanned aerial vehicle radar platform. The two are inconsistent due to the existence of motion errors. Therefore, the echo data is phase compensated according to the predetermined trajectory and motion data to obtain compensated echo data; the compensated echo data is used for radar imaging to obtain the initial image, thereby reducing the motion error and improving the imaging quality.

[0116] Step 202: Divide the initial image into four sub-images according to four preset scalers.

[0117] Specifically, Figure 4 The schematic diagram of the division of the initial image shown in FIG. 1 shows a calibration object A in each sub-image, a calibration object B in sub-image 2, a calibration object C in sub-image 3, and a calibration object D in sub-image 4.

[0118] Step 203: According to the predetermined track of the target radar, the calibrator and the corresponding sub-image, the phase error of the sub-image is calculated.

[0119] Specifically, for each sub-image, execute:

[0120] extracting a complex image corresponding to the calibrator from the sub-image;

[0121] Perform echo reconstruction on the complex image, and obtain the first reconstructed echo data of the calibrator by the aforementioned formula (1);

[0122] Determining an ideal point position of the calibrator according to the position of the calibrator in the sub-image, the motion data and the predetermined trajectory of the target radar;

[0123] According to the aforementioned formula (2), the second reconstructed echo data corresponding to the calibrator at the ideal point position is obtained;

[0124] According to the first reconstructed echo data and the second reconstructed echo data, the phase error is obtained by the aforementioned formula (3).

[0125] Step 204: performing error compensation on the sub-image according to the phase error to obtain a focused sub-image.

[0126] Specifically, for each sub-image, execute:

[0127] Acquire the echo data and phase error corresponding to the sub-image;

[0128] The echo data is conjugate-multiplied with the phase error, and the target echo data is obtained by the aforementioned formula (4);

[0129] The filter-back projection algorithm is used to perform imaging according to the target echo data to obtain a focused sub-image.

[0130] Step 205: stitching the focused sub-images to obtain a target radar image.

[0131] Specifically, an image stitching algorithm is used to stitch the four focused sub-images to obtain a target radar image.

[0132] like Figure 5 , Figure 6 As shown, an embodiment of the present invention provides a radar imaging focusing device. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, Figure 5 As shown, it is a hardware architecture diagram of a computing device where a radar imaging focusing device provided by an embodiment of the present invention is located, except Figure 5 In addition to the processor, memory, network interface, and non-volatile memory shown in the figure, the computing device in which the device is located in the embodiment may also generally include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking software implementation as an example, Figure 6As shown, as a device in a logical sense, the CPU of the computing device in which it is located reads the corresponding computer program in the non-volatile memory into the memory and runs it. A radar imaging focusing device provided in this embodiment includes: an acquisition module 600, a first imaging module 602, a division module 604, a processing module 606, a second imaging module 608 and a splicing module 610;

[0133] An acquisition module 600 is used to acquire echo data and motion data of a target radar;

[0134] A first imaging module 602, configured to perform radar imaging according to the echo data and the motion data to obtain an initial image;

[0135] A division module 604 is used to divide the initial image into at least two sub-images according to at least two preset calibrators; wherein each sub-image corresponds to one calibrator;

[0136] The processing module 606 is used to calculate the phase error of the sub-image according to the predetermined track of the target radar, the calibrator and the corresponding sub-image;

[0137] A second imaging module 608, configured to perform error compensation on the sub-image according to the phase error to obtain a focused sub-image;

[0138] The stitching module 610 is used to stitch the focused sub-images to obtain a target radar image.

[0139] In some specific embodiments, the acquisition module 600 can be used to execute the above step 100, the first imaging module 602 can be used to execute the above step 102, the division module 604 can be used to execute the above step 104, the processing module 606 can be used to execute the above step 106, the second imaging module 608 can be used to execute the above step 108, and the stitching module 610 can be used to execute the above step 110.

[0140] In some specific implementations, the first imaging module 602 is configured to perform the following operations:

[0141] Performing phase compensation on the echo data according to the predetermined trajectory and motion data to obtain compensated echo data;

[0142] The compensated echo data is used for radar imaging to obtain an initial image.

[0143] In some specific implementations, the partitioning module 604 is used to perform the following operations:

[0144] The initial image is equally divided into at least 2 sub-images, and the number of calibrators is the same as the number of sub-images.

[0145] In some specific implementations, the processing module 606 is configured to perform the following operations:

[0146] For each sub-image, execute:

[0147] extracting a complex image corresponding to the calibrator from the sub-image;

[0148] Performing echo reconstruction on the complex image to obtain first reconstructed echo data of the calibrator;

[0149] Determining an ideal point position of the calibrator according to the position of the calibrator in the sub-image, the motion data and the predetermined trajectory of the target radar;

[0150] Acquire second reconstructed echo data corresponding to the calibrator at the ideal point position;

[0151] Obtaining a phase error according to the first reconstructed echo data and the second reconstructed echo data;

[0152] The first reconstructed echo data is determined by the following formula:

[0153] S r (θ,K)=∫∫ xy g ε (x, y)·exp(-j2KR xy (θ))dxdy

[0154] Among them, S r (θ, K) is used to characterize the first reconstructed echo data; g ε (x, y) is used to represent the complex image, where (x, y) is used to represent the pixel coordinates in the complex image; R xy (θ) is used to characterize the distance from the pixel point in the complex image to the target radar; K is used to characterize the range wave number;

[0155] The second reconstructed echo data is determined by the following formula:

[0156] H A (θ,K)=exp(-j2KR Ae (θ)

[0157] Among them, H A (θ, K) is used to characterize the second reconstructed echo data; R Ae (θ) is used to characterize the distance from the ideal point position to the predetermined trajectory of the target radar; K is used to characterize the range wave number;

[0158] The phase error is determined by the following formula:

[0159]

[0160] in, Used to characterize phase error; S r (θ, K) is used to characterize the first reconstructed echo data; H A (θ, K) is used to characterize the second reconstructed echo data; * represents conjugation; K is used to characterize the range wave number.

[0161] In some specific implementations, the second imaging module 608 is configured to perform the following operations:

[0162] For each sub-image, execute:

[0163] Acquire the echo data and phase error corresponding to the sub-image;

[0164] Conjugate multiplying the echo data with the phase error to obtain target echo data;

[0165] Perform imaging according to the target echo data to obtain a focused sub-image;

[0166] The target echo data is determined by the following formula:

[0167]

[0168] Among them, S 1 (θ, K) is used to characterize the target echo data; S 0 (θ, K) is used to characterize the echo data of the target radar; Used to characterize phase error; K is used to characterize the range wave number.

[0169] In some specific implementations, the second imaging module 608 uses a filtering-back projection algorithm to perform imaging.

[0170] It is to be understood that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on a radar imaging focusing device. In other embodiments of the present invention, a radar imaging focusing device may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0171] The information interaction, execution process and other contents between the modules in the above-mentioned device are based on the same concept as the embodiment of the method of the present invention. For the specific contents, please refer to the description in the embodiment of the method of the present invention, and no further description is given here.

[0172] An embodiment of the present invention further provides a computing device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, a radar imaging focusing method in any embodiment of the present invention is implemented.

[0173] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor executes a radar imaging focusing method in any embodiment of the present invention.

[0174] Specifically, a system or device equipped with a storage medium can be provided, on which software program code that implements the functions of any of the above-mentioned embodiments is stored, and a computer (or CPU or MPU) of the system or device can be enabled to read and execute the program code stored in the storage medium.

[0175] In this case, the program code itself read from the storage medium can realize the function of any one of the above-mentioned embodiments, and thus the program code and the storage medium storing the program code constitute a part of the present invention.

[0176] The storage medium embodiments for providing the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), a magnetic tape, a non-volatile memory card, and a ROM. Alternatively, the program code can be downloaded from a server computer by a communication network.

[0177] In addition, it should be clear that the functions of any of the above embodiments can be implemented not only by executing the program code read by the computer, but also by enabling an operating system operating on the computer to complete part or all of the actual operations based on instructions from the program code.

[0178] In addition, it can be understood that the program code read from the storage medium is written to a memory provided in an expansion board inserted into the computer or to a memory provided in an expansion module connected to the computer, and then based on the instructions of the program code, a CPU installed on the expansion board or expansion module is enabled to perform part or all of the actual operations, thereby realizing the functions of any of the above-mentioned embodiments.

[0179] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical factors in the process, method, article or device including the elements.

[0180] A person of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, etc., various media that can store program codes.

[0181] 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 radar imaging focusing method, characterized in that: include: Obtain target radar echo data and motion data; Perform radar imaging according to the echo data and the motion data to obtain an initial image; According to at least two preset calibrators, the initial image is divided into at least two sub-images; wherein each of the sub-images corresponds to a calibrator; According to the predetermined track of the target radar, the calibrator and the corresponding sub-image, a phase error of the sub-image is calculated; Performing error compensation on the sub-image according to the phase error to obtain a focused sub-image; The focused sub-images are stitched together to obtain a target radar image.

2. The method according to claim 1, characterized in that The performing radar imaging according to the echo data and the motion data to obtain an initial image includes: performing phase compensation on the echo data according to the predetermined trajectory and the motion data to obtain compensated echo data; The compensated echo data is used to perform radar imaging to obtain an initial image.

3. The method according to claim 1, characterized in that The number of the scalers is the same as the number of the sub-images; and / or, Dividing the initial image into at least two sub-images; and / or, The calibrators are evenly distributed around the target object to be measured.

4. The method according to claim 1, characterized in that: The step of calculating the phase error of the sub-image according to the predetermined track of the target radar, the calibrator and the sub-image corresponding thereto comprises: For each sub-image, execute: extracting a complex image corresponding to the calibrator from the sub-image; Performing echo reconstruction on the complex image to obtain first reconstructed echo data of the calibrator; Determining the ideal point position of the calibrator according to the position of the calibrator in the sub-image, the motion data and the predetermined trajectory of the target radar; Acquire second reconstructed echo data corresponding to the calibrator at the ideal point position; A phase error is obtained according to the first reconstructed echo data and the second reconstructed echo data.

5. The method according to claim 4, characterized in that The first reconstructed echo data is determined by the following formula: S r (θ, K)=∫∫ xy g ε (x,y)·exp(-j2KR xy (i))dxdy Among them, S r (θ, K) is used to characterize the first reconstructed echo data; g ε (x, y) is used to represent the complex image, wherein (x, y) is used to represent the pixel coordinates in the complex image; R xy (θ) is used to characterize the distance from the pixel point in the complex image to the target radar; K is used to characterize the range wave number; The second reconstructed echo data is determined by the following formula: H A (θ,K)=exp(-j2KR Ae (i)) Among them, H A (θ, K) is used to characterize the second reconstructed echo data; R Ae (θ) is used to characterize the distance from the ideal point position to the predetermined track of the target radar; K is used to characterize the range wave number; and / or, The phase error is determined by the following formula: in, Used to characterize the phase error; S r (θ, K) is used to characterize the first reconstructed echo data; H A (θ, K) is used to characterize the second reconstructed echo data; * represents conjugation; K is used to characterize the range wave number.

6. The method according to any one of claims 1 to 5, characterized in that: The step of performing error compensation on the sub-image according to the phase error to obtain a focused sub-image comprises: For each sub-image, execute: Acquire the echo data and phase error corresponding to the sub-image; Conjugate multiplying the echo data with the phase error to obtain target echo data; Imaging is performed according to the target echo data to obtain a focused sub-image.

7. The method according to claim 6, characterized in that The imaging adopts a filtering-back projection algorithm; and / or, The target echo data is determined by the following formula: Wherein, S1(θ, K) is used to characterize the target echo data; S0(θ, K) is used to characterize the echo data; It is used to characterize the phase error; K is used to characterize the range wave number.

8. A radar imaging focusing device, characterized in that: include: An acquisition module is used to acquire the echo data and motion data of the target radar; A first imaging module, used for performing radar imaging according to the echo data and the motion data to obtain an initial image; A division module, used for dividing the initial image into at least two sub-images according to at least two preset calibrators; wherein each of the sub-images corresponds to one calibrator; A processing module, used for calculating the phase error of the sub-image according to the predetermined track of the target radar, the calibrator and the corresponding sub-image; A second imaging module, used for performing error compensation on the sub-image according to the phase error to obtain a focused sub-image; The stitching module is used to stitch the focused sub-images to obtain a target radar image.

9. A computing device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 7.

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