Synthetic aperture radar positioning method and device

Abstract

The present invention provides a synthetic aperture radar positioning method and device, the method comprising: acquiring multiple SAR images, and extracting a single-view complex image and pixel data of a target object from each SAR image; each SAR image is obtained after the radar performs side-view imaging on the target object, and the side-view imaging incident angles of each SAR image are different; performing target object recognition on each single-view complex image to obtain the sub-pixel position of the target object in each SAR image; determining the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object and the slant range correction value; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located; and determining the positioning result of the target object based on the difference between the three-dimensional positions of each target object. The present invention can further improve the accuracy of the positioning result of the target object.

Description

Technical Field

[0001] The present invention relates to the technical field of image processing, and in particular to a synthetic aperture radar positioning method and device. Background Art

[0002] High-precision positioning using synthetic aperture radar images (SAR images) is one of the important technical ways to obtain basic geographic information. It has completely different characteristics from optical images. Synthetic aperture radar is an active remote sensing method with the characteristics of not being restricted by time. Using synthetic aperture radar images to obtain three-dimensional position information of ground targets has the advantages of high precision, all-day, all-weather, fast, and not being restricted by regional geography, climate and other conditions.

[0003] At present, positioning is mostly done by constructing a general positioning model or a special positioning model for SAR images. The general positioning model generally adopts an approximate processing method to directly simulate the geometric distortion of the image itself mathematically. Its accuracy mainly depends on the model's fit to the geometric deformation and the accuracy of the control information. However, when the maximum elevation difference of the average elevation surface is greater than the ground elevation difference, the positioning accuracy of the general positioning model is low. The special positioning model is mainly a model established for the geometric process of imaging. Its accuracy mainly depends on the rigor of the model and the accuracy of the parameters, including the collinear equation model and the range-Doppler positioning model. However, the positioning accuracy of the special positioning model is low when there is no ground control point in a single SAR image. Summary of the invention

[0004] The present invention provides a synthetic aperture radar positioning method and device, which are used to solve the defect of low synthetic aperture radar positioning accuracy in the prior art.

[0005] The present invention provides a synthetic aperture radar positioning method, comprising:

[0006] Acquire multiple SAR images, and extract the single-view complex image and pixel data of the target object from each SAR image; each SAR image is obtained after the radar performs side-view imaging of the target object, and the side-view imaging incident angle of each SAR image is different;

[0007] Perform target object recognition on each single-view complex image to obtain the sub-pixel position of the target object in each SAR image;

[0008] Determine the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object and the slant range correction value; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located;

[0009] Based on the difference between the three-dimensional positions of the target objects, the positioning results of the target objects are determined.

[0010] According to a synthetic aperture radar positioning method provided by the present invention, the three-dimensional position of the target object in each SAR image is determined based on each pixel data, the sub-pixel position of each target object and the slant range correction value, including:

[0011] The pixel data are grouped based on the side imaging incident angle of each SAR image;

[0012] Based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, the three-dimensional position of the target object in each group is determined.

[0013] According to a synthetic aperture radar positioning method provided by the present invention, the three-dimensional position of the target object in each group is determined based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, including:

[0014] Based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, a three-dimensional position equation group corresponding to each group is established;

[0015] The three-dimensional position equation group of each group is solved to obtain the three-dimensional position of the target object in each group.

[0016] According to a synthetic aperture radar positioning method provided by the present invention, the positioning result of the target object is determined based on the difference between the three-dimensional positions of each target object, including:

[0017] Determining the three-dimensional position accuracy of the target object in each SAR image based on the difference between the three-dimensional positions of the target object in each SAR image;

[0018] When the three-dimensional position accuracy of the target object in any SAR image is greater than a threshold, the three-dimensional position of the corresponding target object is used as the positioning result of the target object.

[0019] According to a synthetic aperture radar positioning method provided by the present invention, the difference between the three-dimensional positions of the target objects in each SAR image is determined based on the variance between the positions of the target objects.

[0020] According to a synthetic aperture radar positioning method provided by the present invention, the sub-pixel position of the target object in each SAR image is obtained, and then the method further includes:

[0021] Based on the sub-pixel position of each target object and the slant range correction value, the two-dimensional position of the target object in each SAR image is determined.

[0022] The present invention also provides a synthetic aperture radar positioning device, comprising:

[0023] An acquisition unit is used to acquire multiple SAR images and extract a single-view complex image and pixel data of the target object from each SAR image; each SAR image is obtained after the radar performs side-view imaging on the target object, and the side-view imaging incident angle of each SAR image is different;

[0024] The recognition unit is used to perform target object recognition on each single-view complex image to obtain the sub-pixel position of the target object in each SAR image;

[0025] A determination unit, configured to determine the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object, and a slant range correction value; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located;

[0026] The positioning unit is used to determine the positioning result of the target object based on the difference between the three-dimensional positions of the target objects.

[0027] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the synthetic aperture radar positioning method described above is implemented.

[0028] The present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the synthetic aperture radar positioning method as described in any one of the above is implemented.

[0029] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements any one of the synthetic aperture radar positioning methods described above.

[0030] The synthetic aperture radar positioning method and device provided by the present invention can accurately determine the three-dimensional position of the target object in each SAR image based on the pixel data corresponding to multiple SAR images, the sub-pixel position of the target object and the slant range correction value, thereby avoiding the problem that a single SAR image in the traditional method cannot accurately determine the phase center of the target object. At the same time, the present invention does not require ground control points to determine the three-dimensional position of the target object, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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.

[0032] Figure 1 This is one of the flow charts of the synthetic aperture radar positioning method provided by the present invention;

[0033] Figure 2 It is a schematic flow chart of a method for determining a three-dimensional position of a target object provided by the present invention;

[0034] Figure 3 This is the second flow chart of the synthetic aperture radar positioning method provided by the present invention;

[0035] Figure 4 It is a structural schematic diagram of the synthetic aperture radar positioning device provided by the present invention;

[0036] Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0038] At present, positioning is mostly carried out by constructing a general positioning model or a special positioning model for SAR images. The general positioning model generally adopts an approximate processing method to directly simulate the geometric distortion of the image itself mathematically. Its accuracy mainly depends on the model's fit to the geometric deformation and the accuracy of the control information. The general positioning model includes a general polynomial model and a rational function model. The general polynomial model is usually a second-order or third-order polynomial, and is only a transformation between two planes, but it does not consider the influence of terrain and is only suitable for SAR image positioning in flat areas. Therefore, when the maximum elevation difference between the ground point and the average elevation surface is greater than the ground elevation difference, the general polynomial model has low accuracy and relies on a large number of high-precision uniformly distributed control points during geometric correction; the rational function model (such as the generalized sensor model RFM) uses rational functions to approximate the mapping relationship between the two-dimensional image plane and the three-dimensional space for positioning, but there are many parameters in the model that have no physical meaning, and it is impossible to qualitatively explain the role of these parameters and the impact on positioning accuracy. The model is less stable and cannot guarantee the accuracy of images over a large range.

[0039] The dedicated positioning model is mainly a model established for the geometric process of imaging. Its accuracy mainly depends on the rigor of the model and the accuracy of the parameters, including the collinear equation model and the range-Doppler positioning model. The collinear equation model is a SAR image imaging model based on horizontal range projection, but the equation has a high positioning accuracy only for the image of horizontal range center projection, while it requires additional conversion for slant range SAR images, which not only increases the amount of calculation, but also requires a large number of control points, resulting in high cost. The range-Doppler positioning model mainly uses the distance equation, Doppler equation and earth ellipsoid equation for positioning solution, but the positioning accuracy is low for a single SAR image without ground control points. In addition, since the SAR image is a side-view imaging, the phase center of the object is offset during imaging, so the phase center on the image does not completely coincide with the actual phase center, so it is difficult to accurately determine the phase center of the object, resulting in low positioning accuracy.

[0040] To this end, the present invention provides a synthetic aperture radar positioning method. Figure 1 It is one of the flow charts of the synthetic aperture radar positioning method provided by the present invention, such as Figure 1 As shown, the method comprises the following steps:

[0041] Step 110, acquiring multiple SAR images, and extracting a single-view complex image and pixel data of the target object from each SAR image; each SAR image is obtained after the radar performs side-view imaging of the target object, and the side-view imaging incident angle of each SAR image is different.

[0042] Here, multiple SAR images are obtained after the radar performs side-view imaging on the target object, and the side-view imaging incident angles of each SAR image are different. It should be noted that since the SAR image is obtained after side-view imaging, the center of the target object in the SAR image will be offset, that is, the phase center of the target object on the SAR image does not completely coincide with the actual phase center of the target object. Therefore, the embodiment of the present invention performs stereo positioning of the target object by acquiring multiple SAR images with different side-view imaging incident angles, so that the phase center of the target object can be obtained more accurately. In addition, since there is a sufficient angular interval between the SAR images with different side-view imaging incident angles, the basic three-dimensional position of the target object can be accurately determined, so that a stereoscopic setting can be performed and the CR coordinates can be finally retrieved, thereby more accurately determining the height component, that is, more accurately obtaining the phase center of the target object.

[0043] A single look complex image (SLC image) is a SAR image formed by a synthetic aperture length without superposition with other SAR images. The synthetic aperture length used is usually long, so the azimuth resolution is high, which can facilitate subsequent accurate target object recognition. Pixel data (such as par data) can be used to characterize the aspect ratio of a single pixel in a SAR image.

[0044] Step 120: Perform target object recognition on each single-view complex image to obtain the sub-pixel position of the target object in each SAR image.

[0045] Specifically, after acquiring the SLC image, the target object in the SLC image can be identified, the actual position of the target object in the SLC image can be obtained, and then point target analysis can be performed based on the actual position to extract the sub-pixel position of the target object. The sub-pixel position of the target object can be extracted by performing complex fast Fourier transform oversampling and finding the maximum peak to detect the sub-pixel position of the target object through parabola fitting. The peak position detected represents the effective phase center of the target object.

[0046] Step 130: Determine the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object, and the slant range correction value; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located.

[0047] Specifically, the slant range correction value may include at least one of the earth solid tide correction value, the atmosphere correction value and the ionosphere correction value. Since synthetic aperture radar observations are affected by the interaction between radio signals and the atmosphere and the change of the target position by geophysical signals, there is a positioning error. Among them, the satellite dynamics during signal transmission and reception and the onboard timing system have an impact on the distance and azimuth directions, as do geodynamic signals, and the propagation delay caused by the atmosphere affects the distance observation value. At this time, in order to obtain high-precision positioning results, these influencing factors need to be corrected, so the earth solid tide correction value, the atmosphere correction value and the ionosphere correction value are introduced. The accuracy of the slant range-Doppler positioning algorithm mainly depends on the slant range measurement accuracy, the platform ephemeris error and the influence of terrain undulation. The radar system indirectly measures the geometric distance through the propagation time of the radar pulse from the radar transmitter to the ground and back to the radar receiver. Usually, the conversion from travel time to geometric distance refers to the vacuum speed of light. However, electrons in the ionosphere, dry air, and water vapor in the troposphere introduce additional signal delays, making the signal propagation speed less than the speed of light, so the atmospheric correction delay needs to be considered. Geodynamic effects, such as solid earth tides and continental drift, offset the true position of ground targets by several centimeters over a day or a few years, respectively, so solid earth tide corrections also need to be considered. Among them, the slant range correction value is determined based on the longitude and latitude of the area where the target object is located.

[0048] Optionally, the initial three-dimensional position of the target object can be determined in combination with each pixel data and the sub-pixel position of each target object. Since the atmosphere, ionosphere, etc. may cause signal delays, resulting in a deviation between the obtained initial three-dimensional position and the actual three-dimensional position of the target object, the initial three-dimensional position can be corrected by the slant range correction value to accurately obtain the three-dimensional position of the target object in each SAR image. That is, the embodiment of the present invention can determine the three-dimensional position of the target object without the need for ground control points, and the cost is low.

[0049] In addition, the traditional method mostly obtains the three-dimensional position of the target object through the multi-directional airborne SAR scene and the local Cartesian coordinate system, that is, the height of the target object is inferred from the change of the dwell time caused by different observation geometries. Specifically, the pixels of the inclined range SAR image are first geocoded, and then the CRs and the height of the target object are estimated by combining the scene pairs for stereo-based height estimation, but excessive attention is paid to the height component and the accuracy of other components is ignored. However, in the embodiment of the present invention, the initial three-dimensional position is corrected based on the slant range correction value to obtain the three-dimensional position of the target object without the need for external information assistance, thereby ensuring the accuracy of the three-dimensional position of the target object.

[0050] Step 140: Determine the positioning result of the target object based on the difference between the three-dimensional positions of the target objects.

[0051] Specifically, due to the different incident angles of the side-view imaging, the obtained three-dimensional positions of the target objects may differ. If the three-dimensional position of any target object differs greatly from the three-dimensional positions of all other target objects, it indicates that there is a high probability that the three-dimensional position of the target object has a deviation. Optionally, based on the difference between the three-dimensional positions of the target objects, the accuracy of the three-dimensional position of each target object can be determined, and the three-dimensional position of the target object corresponding to the maximum accuracy can be used as the positioning result of the target object.

[0052] The synthetic aperture radar positioning method provided by the embodiment of the present invention can accurately determine the three-dimensional position of the target object in each SAR image based on the pixel data corresponding to multiple SAR images, the sub-pixel position of the target object, and the slant range correction value, thereby avoiding the problem that a single SAR image in the traditional method cannot accurately determine the phase center of the target object. At the same time, the embodiment of the present invention does not require ground control points to determine the three-dimensional position of the target object, and the cost is low.

[0053] Based on the above embodiment, the three-dimensional position of the target object in each SAR image is determined based on each pixel data, the sub-pixel position of each target object and the slant range correction value, including:

[0054] The pixel data are grouped based on the side imaging incident angle of each SAR image;

[0055] Based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, the three-dimensional position of the target object in each group is determined.

[0056] Specifically, the side-view imaging incident angles of the SAR images are different, and the corresponding measurement errors will also be different, that is, the weights of the measurement errors are different. In this regard, the embodiment of the present invention groups the pixel data based on the side-view imaging incident angles of each SAR image, that is, the pixel data with the same side-view imaging incident angle are grouped, and the three-dimensional position of the target object in each group is obtained based on the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group. Since the weights of the measurement errors in the same group are the same, the three-dimensional position of the target object in each group can be accurately obtained based on the pixel data, sub-pixel position and slant range correction value in the same group.

[0057] like Figure 2As shown in the figure, when determining the three-dimensional position of the target object in the m SAR images, the m SAR images can be preprocessed to obtain the corresponding par data (pixel data), and the par data can be written into the text document in the storage order of the binary file corresponding to the point target in sequence, and the par data can be stored as SLC_par_table.txt. At the same time, the SLC images corresponding to the m SAR images with different incident angles are used to find the target objects at the same position, and the point target analysis is performed to extract the sub-pixel positions, and these sub-pixel positions are stored as a binary file named plists.bin. Then, the binary file of the slant range correction value corresponding to the m SLC images is input and named prd.bin. The par data is grouped according to the different incident angles, and the grouping information is written into the text document at one time according to the storage order of the binary file corresponding to the point target, named G_table.txt. Then, the three-dimensional coordinates of the target object in the image are determined according to the m SLC images, and stored as a binary file: pllh0.bin, and then the number of iterations is input, and finally the result file is named to obtain the three-dimensional position of the target object.

[0058] Based on any of the above embodiments, based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, determining the three-dimensional position of the target object in each group includes:

[0059] Based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, a three-dimensional position equation group corresponding to each group is established;

[0060] The three-dimensional position equation group of each group is solved to obtain the three-dimensional position of the target object in each group.

[0061] Specifically, the side-view imaging incident angle of the SAR image is different, and the corresponding measurement errors will also be different, that is, the weights of each measurement error are different. In this regard, the embodiment of the present invention groups the pixel data with the same side-view imaging incident angle into one group, and establishes a corresponding three-dimensional position equation group based on the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, so that the three-dimensional position of the target object in each group can be obtained by solving the equation group. Since the measurement errors in the same group have the same weight, the three-dimensional position of the target object in each group can be accurately obtained based on the pixel data, sub-pixel position and slant range correction value in the same group, further improving the positioning accuracy of the target object.

[0062] Based on any of the above embodiments, determining the positioning result of the target object based on the difference between the three-dimensional positions of each target object includes:

[0063] Determining the three-dimensional position accuracy of the target object in each SAR image based on the difference between the three-dimensional positions of the target object in each SAR image;

[0064] When the three-dimensional position accuracy of the target object in any SAR image is greater than a threshold, the three-dimensional position of the corresponding target object is used as the positioning result of the target object.

[0065] Specifically, due to the different incident angles of side-view imaging, there may be differences between the three-dimensional positions of the target objects obtained. If the three-dimensional position of any target object is significantly different from the three-dimensional positions of all other target objects, it indicates that there is a high probability that the three-dimensional position of the target object is deviated.

[0066] After determining the difference between the three-dimensional positions of each target object, the three-dimensional position accuracy of each target object can be determined. When the three-dimensional position accuracy of the target object in any SAR image is greater than a threshold, it indicates that the three-dimensional position reliability of the corresponding target object is high. At this time, the three-dimensional position of the corresponding target object can be used as the positioning result of the target object. Among them, the distribution of all three-dimensional positions can be determined based on the three-dimensional position of each target object, and then the center of the most densely distributed area is used as the three-dimensional position standard value of the target object, and the difference between the three-dimensional position of each target object and the three-dimensional position standard value is used as the three-dimensional position accuracy of each target object.

[0067] Based on any of the above embodiments, the difference between the three-dimensional positions of the target objects in each SAR image is determined based on the variance between the positions of each target object.

[0068] Specifically, in the process of solving the three-dimensional position of the target object using the three-dimensional position equation group, the diagonal value in the variance-covariance matrix of the three-dimensional position (that is, the variance between the positions of each target object) can be used as the difference between the three-dimensional positions of each target object. The smaller the variance, the higher the accuracy of the three-dimensional position of the corresponding target object, and vice versa.

[0069] Based on any of the above embodiments, the sub-pixel position of the target object in each SAR image is obtained, and then the following steps are further included:

[0070] The two-dimensional position of the target object in each SAR image is determined based on the sub-pixel position of each target object and the slant range correction value.

[0071] Specifically, when determining the two-dimensional position of the target object in each SAR image, the target object can be identified for each SLC image to obtain the actual position coordinates of the target object in the SLC image, and the actual position coordinates can be analyzed by point target to determine the corresponding sub-pixel position, and then the initial two-dimensional coordinates of the target object are determined based on the sub-pixel position, and the initial two-dimensional coordinates are corrected based on the slant range correction value to finally obtain the two-dimensional position of the target object. It can be understood that based on the two-dimensional position of the target object, the distribution of the two-dimensional position of the target object obtained in each SAR image can be obtained, for example, the two-dimensional position of the target object corresponding to the densely distributed area has a higher degree of credibility, and the two-dimensional position of the target object corresponding to the sparsely distributed area has a lower degree of credibility.

[0072] Based on any of the above embodiments, the present invention also provides a synthetic aperture radar positioning method, such as Figure 3 As shown, the method comprises the following steps:

[0073] Step a: receiving a plurality of SAR images; wherein the satellite-borne radar performs side-view imaging of the target object to obtain a plurality of SAR images;

[0074] Step b: Preprocess the SAR image to obtain multiple single-view complex image (SLC image) data and par data of the target object.

[0075] Step c: In two-dimensional positioning, select the above single SLC image, identify the target object, obtain the actual position of the target object in the SLC image, and perform point target analysis (PTA) to extract the sub-pixel position. The process is to perform complex fast Fourier transform oversampling and find the sub-pixel position of the maximum peak detection target through parabola fitting. This peak position represents the effective phase center of the target object.

[0076] Step d: Calculate the earth's solid tide correction value, atmosphere correction value, ionosphere correction value, etc. according to the current longitude and latitude and current time information.

[0077] Step e: Perform single SAR image positioning, and calculate the two-dimensional position of the target object in combination with the sub-pixel position in step c and the correction values ​​in step d, thereby realizing the positioning test of the single SAR image.

[0078] Step f: During three-dimensional positioning, use multiple SLC images with different incident angles to find the target objects at the same position, perform point target analysis (PTA) on each of them, extract the sub-pixel position, and combine the correction values ​​in step d and the pixel data of each SAR image (such as par data) to obtain the three-dimensional position of the target object, thereby realizing the stereo positioning test of multiple SAR images.

[0079] Step g: Evaluate the coordinate accuracy. The three-dimensional position accuracy of the target object can be defined as the difference between the ground truth value and the measured (or estimated) position. The three-dimensional position accuracy of the target object can be determined based on the size of the difference. The three-dimensional position accuracy can also be determined based on the diagonal values ​​in the variance-covariance matrix of the solved coordinates generated during the three-dimensional positioning process. The smaller the variance, the higher the accuracy.

[0080] The synthetic aperture radar positioning device provided by the present invention is described below. The synthetic aperture radar positioning device described below and the synthetic aperture radar positioning method described above can be referred to each other.

[0081] Based on any of the above embodiments, the present invention also provides a synthetic aperture radar positioning device, such as Figure 4 As shown, the device comprises:

[0082] The acquisition unit 410 is used to acquire multiple SAR images and extract the single-view complex image and pixel data of the target object from each SAR image; each SAR image is obtained after the radar performs side-view imaging on the target object, and the side-view imaging incident angle of each SAR image is different;

[0083] The recognition unit 420 is used to perform target object recognition on each single-view complex image to obtain the sub-pixel position of the target object in each SAR image;

[0084] A determination unit 430, configured to determine the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object, and a slant range correction value; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located;

[0085] The positioning unit 440 is used to determine the positioning result of the target object based on the difference between the three-dimensional positions of the target objects.

[0086] Based on any of the above embodiments, the determining unit 430 includes:

[0087] A grouping unit, used for grouping each pixel data based on the side imaging incident angle of each SAR image;

[0088] The first calculation unit is used to determine the three-dimensional position of the target object in each group based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group.

[0089] Based on any of the above embodiments, the first computing unit includes:

[0090] A construction unit, used to establish a three-dimensional position equation group corresponding to each group based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group;

[0091] The second calculation unit is used to solve the three-dimensional position equation group of each group to obtain the three-dimensional position of the target object in each group.

[0092] Based on any of the above embodiments, the positioning unit 440 includes:

[0093] an accuracy determination unit, configured to determine the accuracy of the three-dimensional position of the target object in each SAR image based on the difference between the three-dimensional positions of the target object in each SAR image;

[0094] The result determination unit is used to use the three-dimensional position of the corresponding target object as the positioning result of the target object when the three-dimensional position accuracy of the target object in any SAR image is greater than a threshold.

[0095] Based on any of the above embodiments, the difference between the three-dimensional positions of the target objects in each SAR image is determined based on the variance between the positions of each target object.

[0096] Based on any of the above embodiments, the device further includes:

[0097] The two-dimensional positioning unit is used to determine the two-dimensional position of the target object in each SAR image based on the sub-pixel position of each target object and the slant range correction value after obtaining the sub-pixel position of the target object in each SAR image.

[0098] Figure 5 is a schematic diagram of the structure of the electronic device provided by the present invention, such as Figure 5As shown, the electronic device may include: a processor 510, a memory 520, a communication interface 530 and a communication bus 540, wherein the processor 510, the memory 520 and the communication interface 530 communicate with each other through the communication bus 540. The processor 510 may call the logic instructions in the memory 520 to execute the synthetic aperture radar positioning method, which includes: acquiring multiple SAR images, and extracting a single-view complex image and pixel data of a target object from each SAR image; each SAR image is obtained after the radar performs side-view imaging on the target object, and the side-view imaging incident angles of each SAR image are different; performing target object recognition on each single-view complex image to obtain the sub-pixel position of the target object in each SAR image; determining the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object and the slant range correction value; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located; and determining the positioning result of the target object based on the difference between the three-dimensional positions of each target object.

[0099] In addition, the logic instructions in the above-mentioned memory 520 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0100] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the synthetic aperture radar positioning method provided by the above-mentioned methods, and the method includes: acquiring multiple SAR images, and extracting a single-view complex image and pixel data of a target object from each SAR image; each SAR image is obtained after the radar performs side-view imaging on the target object, and the side-view imaging incident angle of each SAR image is different; target object recognition is performed on each single-view complex image to obtain the sub-pixel position of the target object in each SAR image; based on each pixel data, the sub-pixel position of each target object and a slant range correction value, the three-dimensional position of the target object in each SAR image is determined; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located; based on the difference between the three-dimensional positions of each target object, the positioning result of the target object is determined.

[0101] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the synthetic aperture radar positioning methods provided above, the methods comprising: acquiring multiple SAR images, and extracting a single-view complex image and pixel data of a target object from each SAR image; each SAR image is obtained after a radar performs side-view imaging of the target object, and the side-view imaging incident angles of each SAR image are different; performing target object recognition on each single-view complex image to obtain a sub-pixel position of the target object in each SAR image; determining a three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object, and a slant range correction value; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located; and determining a positioning result of the target object based on the difference between the three-dimensional positions of each target object.

[0102] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0103] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0104] 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 synthetic aperture radar positioning method, characterized in that: include: Acquire multiple SAR images, and extract the single-view complex image and pixel data of the target object from each SAR image; each SAR image is obtained after the radar performs side-view imaging of the target object, and the side-view imaging incident angle of each SAR image is different; Perform target object recognition on each single-view complex image to obtain the sub-pixel position of the target object in each SAR image; Determine the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object and the slant range correction value; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located; Determining a positioning result of the target object based on a difference between the three-dimensional positions of the target objects; The method of determining the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object and the slant range correction value includes: Based on the side-view imaging incident angle of each SAR image, each pixel data is grouped; Determine the three-dimensional position of the target object in each group based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group; Determining the three-dimensional position of the target object in each group based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, includes: Based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, a three-dimensional position equation group corresponding to each group is established; The three-dimensional position equation group of each group is solved to obtain the three-dimensional position of the target object in each group.

2. The synthetic aperture radar positioning method according to claim 1, characterized in that: The determining the positioning result of the target object based on the difference between the three-dimensional positions of the target objects includes: Determining the three-dimensional position accuracy of the target object in each SAR image based on the difference between the three-dimensional positions of the target object in each SAR image; When the three-dimensional position accuracy of the target object in any SAR image is greater than a threshold, the three-dimensional position of the corresponding target object is used as the positioning result of the target object.

3. The synthetic aperture radar positioning method according to any one of claims 1 to 2, characterized in that: The difference between the three-dimensional positions of the target objects in each SAR image is determined based on the variance between the positions of the target objects.

4. The synthetic aperture radar positioning method according to any one of claims 1 to 2, characterized in that: The step of obtaining the sub-pixel position of the target object in each SAR image further includes: Based on the sub-pixel position of each target object and the slant range correction value, the two-dimensional position of the target object in each SAR image is determined.

5. A synthetic aperture radar positioning device, characterized in that: include: An acquisition unit, used for acquiring a plurality of SAR images, and extracting a single-view complex image and pixel data of a target object from each SAR image; Each SAR image is obtained after the radar performs side-view imaging of the target object, and the side-view imaging incident angle of each SAR image is different; The recognition unit is used to recognize the target object in each single-view complex image and obtain the sub-pixel position of the target object in each SAR image; A determination unit, configured to determine the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object, and a slant range correction value; the slant range correction value is determined based on the longitude and latitude of the area where the target object is located; A positioning unit, configured to determine a positioning result of the target object based on a difference between three-dimensional positions of the target objects; The method of determining the three-dimensional position of the target object in each SAR image based on each pixel data, the sub-pixel position of each target object and the slant range correction value includes: The pixel data are grouped based on the side imaging incident angle of each SAR image; Determine the three-dimensional position of the target object in each group based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group; Determining the three-dimensional position of the target object in each group based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, includes: Based on the pixel data in each group, and the sub-pixel position and slant range correction value of the target object corresponding to the pixel data in each group, a three-dimensional position equation group corresponding to each group is established; The three-dimensional position equation group of each group is solved to obtain the three-dimensional position of the target object in each group.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the synthetic aperture radar positioning method according to any one of claims 1 to 4 is implemented.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the synthetic aperture radar positioning method according to any one of claims 1 to 4 is implemented.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the synthetic aperture radar positioning method according to any one of claims 1 to 4 is implemented.

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