Target monitoring method and system combining advantages of real aperture radar and synthetic aperture radar
By combining the system of solid aperture radar and synthetic aperture radar, the phase difference processing and decomposition is used for SAR data, and motion compensation is performed, the target accurate positioning and rapid vibration characteristic monitoring are achieved, and the contradiction between positioning accuracy and vibration monitoring in the prior art is solved.
Patent Information
- Application Number
- CN202510194416.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-21
- Publication Date
- 2025-05-30
AI Technical Summary
It is difficult for the prior art to achieve the monitoring of target positioning accuracy and rapid vibration characteristics at the same time. Especially in the monitoring of fast motion or vibration targets, the resolution of the real aperture radar is insufficient, and the scanning period of the synthetic aperture radar is too long, resulting in ambiguity in the monitoring results.
A system combining solid aperture radar (RAR) and synthetic aperture radar (SAR) is used to obtain complex SAR image data multiple times, determine the distance and orientation of the target, and perform phase difference processing to obtain the long-term deformation or displacement of the target. Then, the SAR data is broken down into RAR-like data and motion compensation is performed to obtain the target's fast vibration information.
The positioning accuracy and rapid vibration characteristic monitoring at the same time are achieved, and the contradiction between target positioning and vibration monitoring in the prior art is solved, and the accuracy and efficiency of monitoring are improved.
Smart Images
Figure CN120065160A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a target monitoring method and system combining the advantages of real aperture and synthetic aperture radar, and belongs to the technical field of radar monitoring. Background Art
[0002] In traditional radar technology, synthetic aperture radar (SAR) can provide high-resolution target azimuth information and is suitable for imaging static or slowly moving targets. However, due to the long scanning period of SAR, it is difficult to capture the characteristics of fast-moving or vibrating targets. Real aperture radar (RAR), although having a short sampling period and being able to effectively monitor the fast vibration or deformation of targets, cannot distinguish multiple targets at the same distance due to its limited resolution. Currently, in the monitoring of fast-vibrating targets, if there are multiple targets in the RAR results of real aperture radar, it may be impossible to accurately determine the specific positions of the targets, resulting in ambiguity in the monitoring results. Therefore, there is an urgent need for a radar system that combines real aperture radar RAR and synthetic aperture radar SAR to take advantage of both and solve this technical problem. Summary of the Invention
[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a target monitoring method and system that combines the advantages of real aperture and synthetic aperture radar, which can achieve both the positioning accuracy of the target and the acquisition of the vibration characteristics of the target; To achieve the above object / to solve the above technical problem, the present invention is implemented by the following technical solutions: First aspect: A target monitoring method combining the advantages of real aperture and synthetic aperture radar, the method comprising: Step 1: Through synthetic aperture radar (SAR) imaging, obtain SAR complex image data multiple times to determine the distance and azimuth of the target; Step 2: Based on the distance and azimuth of the target, by performing phase difference processing on the SAR complex image, obtain the long-term deformation or displacement of the target; Step 3: Decompose the SAR complex image data to obtain data similar to RAR data, and use the data similar to RAR data as RAR data after motion compensation; Step 4: Integrate the distance, azimuth, amplitude, and phase information in the SAR complex image and the distance, amplitude, and phase information in the RAR data to obtain the exact azimuth of the target in the RAR data and obtain the fast vibration information of the target.
[0004] Optionally, in step 1, the synthetic aperture radar moves precisely on the synthetic aperture component according to a preset rule while collecting echo data, and the echo data is an array R i , where the range of i is from 0 to S*L / v.
[0005] Optionally, the size calculation formula of the array R is: S*L / v*N where the time to collect one scene of image is L / v, a total of S*L / v groups of data are collected, and the size of each group of data is N.
[0006] Optionally, process the array R according to the focusing method of synthetic aperture radar (SAR) i , focus on the synthetic aperture radar (SAR) complex image data to obtain a SAR image, and the SAR image contains the reflection intensity information and phase information of the targets in the field of view, as well as the spatial position of each target.
[0007] Optionally, for step 3, the motion compensation method is as follows: Perform fast Fourier transform (FFT) on each of the S*L / v groups of data in the array R i to obtain spectral data FR i , and find the peak point K of the spectral data FR i ; According to the distance D of the peak point target, combine with the SAR image to find the strongest pixel at the distance D of the target, and obtain the azimuth information T of this pixel; According to the acquisition time of each group of radar movement data, obtain the position of the radar when acquiring this group of data, obtain the distance difference between the radar and the target during movement, and calculate the phase difference P i ; According to P i calculate and generate a complex number array C with a phase angle of 2*P i and an amplitude of 1 i , use the conjugate complex number of the complex number array C i as the rotation factor to rotate the element at the peak point K in the spectral data FR i to compensate for the distance.
[0008] Optionally, the method for calculating the phase difference P i includes: Taking the center of the straight track as the coordinate origin, with the direction of the straight track from left to right as the X axis, establish a rectangular coordinate system. For the i-th group of data in FR, the position of the radar is expressed as: (-L / 2 + i*v / S, 0); For a stationary target with a distance D from the center of the radar track and an azimuth angle T of the target, when the radar is running, the distance R i between the target and the radar is: R i = (D*D + (-L / 2 + i*v / S)*(-L / 2 + i*v / S) - 2*D*(-L / 2 + i*v / S)*cos(2π - T)) 1 / 2, the resulting phase difference P i is: P i =R i / W.
[0009] Optionally, the motion compensation method further includes: For each peak point K, distance compensation is performed to obtain the compensated complex number array CFR i . For the complex number array CFR i , RAR processing is performed to obtain the target's fast displacement information, and the monitoring rate is S, which is S*L / v times that of the corresponding SAR.
[0010] Second aspect: A target monitoring system that combines the advantages of real aperture and synthetic aperture radar, the system includes: Radar module: Used to obtain SAR complex image data multiple times through synthetic aperture radar (SAR) imaging, and determine the distance and azimuth of the target; Data processing module: Used to obtain the long-term deformation or displacement of the target by performing phase difference processing on the SAR complex image based on the distance and azimuth of the target; Data decomposition module: Used to decompose the SAR complex image data to obtain data similar to RAR; Compensation module: Used to perform motion compensation on the data similar to RAR and then process it as RAR data to obtain the target's fast vibration information; Monitoring module: Used to comprehensively obtain the exact azimuth of the target in the RAR data by combining the distance, azimuth, amplitude, and phase information in the SAR complex image and the distance, amplitude, and phase information in the RAR data, and obtain the target's fast vibration information.
[0011] Third aspect: A computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the target monitoring method described in the first aspect that combines the advantages of real aperture and synthetic aperture radar.
[0012] Fourth aspect: A device, including: A memory for storing instructions; A processor for executing the instructions, so that the device performs the operations of implementing the target monitoring method described in the first aspect that combines the advantages of real aperture and synthetic aperture radar.
[0013] Compared with the prior art, the beneficial effects achieved by the present invention: The present invention combines a system of real aperture radar (RAR) and synthetic aperture radar (SAR) for target positioning and fast vibration monitoring; The present invention can simultaneously take into account the positioning accuracy of the target and monitor and obtain the vibration characteristics of the target. Description of the Drawings
[0014] Figure 1 The following is a schematic flowchart of Embodiment 1 of the present invention. Detailed implementation manners
[0015] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific implementation manners.
[0016] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.
[0017] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.
[0018] This embodiment provides a target monitoring method that combines the advantages of real aperture and synthetic aperture radar. Through the calculation and compensation processing of data, the precise positioning and characteristic analysis of fast-vibrating targets are realized. The method is as follows: Step 1: Operate the synthetic aperture radar (SAR) in its original mode, but process the acquired data in two forms: synthetic aperture radar (SAR) and real aperture radar (RAR) respectively. Step 2: Obtain the SAR complex image of the target area through synthetic aperture radar (SAR) imaging, determine the distance and azimuth of the target. By repeatedly acquiring SAR complex image data and performing interference processing on the SAR complex image, the long-term deformation or displacement of the exact target can be obtained.
[0019] Step 3: Decompose the raw data of SAR to obtain similar RAR data. However, the premise for the RAR radar to monitor target displacement is the stability of the radar itself, while the SAR radar is mobile. Therefore, motion compensation must be performed on the data and then processed as RAR data to obtain the rapid vibration information of the target, solving the problem that it is difficult for SAR to observe the rapid movement and vibration of the target.
[0020] Step 4: Integrate the range, azimuth, amplitude, and phase information in the SAR complex image and the range, amplitude, and phase information in the RAR data to obtain the exact azimuth of the target in the RAR data, and obtain the rapid vibration information of the target, determine the exact azimuth of the target in the RAR data, so as to obtain its spatial position, and solve the problem that RAR cannot obtain the azimuth information of the target.
[0021] In the specific implementation process of this embodiment, the SAR radar is controlled to operate in a conventional manner. The radar module moves precisely on the synthetic aperture component according to a preset rule, and at the same time, echo data is collected. Let this echo data be the array R i . It can be known that the time to collect one scene of imagery is L / v, and a total of S*L / v groups of data are collected, and the size of each group of data is N. Therefore, the size of R is: S*L / v*N, that is, the range of i is from 0 to S*L / v; Step 2. After collecting the data of one scene of SAR imagery, process the array R according to the conventional SAR focusing method i , focus the SAR data to obtain a SAR image, which contains the reflection intensity information and phase information of the targets in the field of view, as well as the spatial position of each target; Step 3. For the array R i , prepare to process it as RAR data. Before processing, perform motion compensation according to the following method: Assume that the start time of scanning this scene of data is t 0 , and the end time is t 1 For the S*L / v groups of data in the array R i , perform fast Fourier transform FFT on each group respectively to obtain the spectral data FR i Find the peak point K of FR i , which indicates that there is target reflection here. However, since RAR cannot obtain azimuth information, at this time, only the distance D of these targets (relative to the center of the straight track) can be known According to the distance D of these peak point targets, in the SAR image generated in Step 2, search for the strongest pixel at this target distance to obtain the azimuth information T (in radians) of this pixel.
[0022] Since the radar moves precisely in a predetermined manner, based on the acquisition time of each set of data, the position of the radar when the set of data is acquired can be obtained, and further the distance difference between the radar and the target when the radar is moving can be obtained. Based on this, the phase difference can be calculated: Taking the center of the straight-line orbit as the coordinate origin, with the direction of the straight-line orbit from left to right as the X-axis, a rectangular coordinate system is established (this coordinate system is consistent with the SAR image coordinate system). For the i-th set of data in FR (i ranges from 0 to S*L / v), the position of the radar can be expressed as: (-L / 2 + i*v / S, 0), and for a stationary target whose distance from the center of the radar orbit (i.e., the coordinate origin) is D and the azimuth is T (in radians), when the radar is operating, the distance R i is: R i = (D*D + (-L / 2 + i*v / S)*(-L / 2 + i*v / S) - 2*D*(-L / 2 + i*v / S)*cos(2π - T)) 1 / 2 , (i ranges from 0 to S*L / v); The phase difference P i caused by this is: P i = R i / W. According to P i calculate and generate a complex number array C i with a phase angle of 2*P i and an amplitude of 1. Using the conjugate complex number of C i as the rotation factor, rotate the element at the peak point K in FR i to compensate for the distance.
[0023] For each reflection peak point, distance compensation is performed, and finally the compensated complex number array CFR i is obtained. For CFR i , conventional RAR processing can be performed to obtain the fast displacement information of the target. The monitoring rate is S, which is S*L / v times that of the corresponding SAR. For example, assuming that the original SAR sampling rate S is 10 Hz, the orbit length is 1 meter, and the running speed is 0.05 m / s, then the monitoring period of the SAR is 20 seconds, that is, the monitoring rate is 0.05 Hz. After adopting this method, the monitoring rate is 10 Hz, the period is 0.1 second, and the monitoring rate is increased by 200 times. The vibration information that could not be monitored by the original RAR can now be extracted.
[0024] Embodiment 2: A target monitoring system that combines the advantages of a real aperture and a synthetic aperture radar. The system includes: Radar module: used to obtain SAR complex image data multiple times through synthetic aperture radar (SAR) imaging to determine the distance and azimuth of the target; Data processing module: used to obtain the long-term deformation or displacement of the target by performing phase difference processing on the SAR complex image based on the distance and azimuth of the target; Data decomposition module: used to decompose the SAR complex image data to obtain data similar to RAR data; Compensation module: used to perform motion compensation on the data similar to RAR data and then process it as RAR data to obtain the rapid vibration information of the target; Monitoring module: used to comprehensively obtain the exact azimuth of the target in the RAR data by integrating the distance, azimuth, amplitude, and phase information in the SAR complex image and the distance, amplitude, and phase information in the RAR data, and obtain the rapid vibration information of the target.
[0025] Embodiment 3: A computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the target monitoring method combining the advantages of real aperture radar and synthetic aperture radar described in Embodiment 1.
[0026] Embodiment 4: A device, comprising: A memory for storing instructions; A processor for executing the instructions, so that the device performs the operations of implementing the target monitoring method combining the advantages of real aperture radar and synthetic aperture radar described in Embodiment 1.
[0027] The system of the present invention combines a real aperture radar (RAR) and a synthetic aperture radar (SAR) for target positioning and rapid vibration monitoring; The present invention can take into account both the positioning accuracy of the target and the vibration characteristics of the target obtained by monitoring.
[0028] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.
Claims
1. A target monitoring method combining the advantages of real aperture and synthetic aperture radar, characterized in that: The method comprises: Step 1: Acquire SAR complex image data multiple times through synthetic aperture radar SAR imaging to determine the distance and direction of the target; Step 2: Based on the distance and orientation of the target, the long-term deformation or displacement of the target is obtained by performing phase difference processing on the SAR complex image; Step 3, decomposing the SAR complex image data to obtain RAR-like data, and performing motion compensation on the RAR-like data as RAR data; Step 4: Integrate the distance, azimuth, amplitude, and phase information in the SAR complex image and the distance, amplitude, and phase information in the RAR data to obtain the exact location of the target in the RAR data and obtain the rapid vibration information of the target.
2. The target monitoring method combining the advantages of real aperture and synthetic aperture radar according to claim 1, characterized in that: In step 1, the synthetic aperture radar moves precisely on the synthetic aperture assembly according to a preset rule, and collects echo data at the same time. The echo data is an array R i , where i ranges from 0 to S*L / v.
3. The target monitoring method combining the advantages of real aperture and synthetic aperture radar according to claim 2, characterized in that: The array R i The size calculation formula is: S*L / v*N The time for collecting one image is L / v, and a total of S*L / v groups of data are collected, and the size of each group of data is N.
4. The target monitoring method combining the advantages of real aperture and synthetic aperture radar according to claim 3 is characterized in that: According to the focusing method of synthetic aperture radar SAR, the array R is processed i , the complex image data of the synthetic aperture radar SAR is focused to obtain a SAR image, which contains the reflection intensity information and phase information of the targets in the field of view, as well as the spatial position of each target.
5. The target monitoring method combining the advantages of real aperture and synthetic aperture radar according to claim 4 is characterized in that: For step 3, the method of motion compensation is as follows: Pair array R i The S*L / v group data in the image are respectively subjected to fast Fourier transform FFT to obtain the spectrum data FR i , and find the spectrum data FR i The peak point K; According to the distance D of the peak point target, the strongest pixel at the target distance D is found in combination with the SAR image, and the azimuth information T of the pixel is obtained; According to the acquisition time of each set of radar movement data, the position of the radar when the set of data is acquired is obtained, the distance difference between the radar and the target when it is moving is obtained, and the phase difference P is calculated. i ; According to P i The calculated phase angle is 2*P i , a complex array C with magnitude 1 i , with the complex array C i The conjugate complex number of is used as the rotator to convert the spectrum data FR i The elements at the peak point K are rotated to compensate for the distance.
6. The target monitoring method combining the advantages of real aperture and synthetic aperture radar according to claim 5, characterized in that: Calculate the phase difference P i The methods include: Take the center of the linear track as the origin of coordinates, and the direction of the linear track from left to right as the X-axis to establish a rectangular coordinate system. For the i-th group of data in FR, the position of the radar is expressed as: (-L / 2+i*v / S,0); For a stationary target whose distance from the center of the radar track is D and whose azimuth angle is T, when the radar is running, the distance between the target and the radar is R i for: R i = (D*D+(-L / 2+i*v / S)*(-L / 2+i*v / S)-2*D*(-L / 2+i*v / S)*cos(2π-T)) 1 / 2 , the resulting phase difference P i For: P i =R i / W.
7. The target monitoring method combining the advantages of real aperture and synthetic aperture radar according to claim 5, characterized in that: The motion compensation method further comprises: For each peak point K, distance compensation is performed to obtain the complex array CFR after compensation i . For complex array CFR i , perform RAR processing to obtain the rapid displacement information of the target. The monitoring rate is S, which is S*L / v times of the corresponding SAR.
8. A target monitoring system combining the advantages of real aperture and synthetic aperture radar, characterized in that: The system comprises: Radar module: used to obtain SAR complex image data multiple times through synthetic aperture radar SAR imaging to determine the distance and direction of the target; Data processing module: used to obtain the long-term deformation or displacement of the target based on the distance and direction of the target by performing phase difference processing on the SAR complex image; Data decomposition module: used to decompose SAR complex image data to obtain RAR-like data; Compensation module: used to process similar RAR data as RAR data after motion compensation to obtain the rapid vibration information of the target; Monitoring module: It is used to integrate the distance, azimuth, amplitude, and phase information in the SAR complex image and the distance, amplitude, and phase information in the RAR data, obtain the exact location of the target in the RAR data, and obtain the rapid vibration information of the target.
9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, a target monitoring method combining the advantages of real aperture radar and synthetic aperture radar as described in any one of claims 1 to 7 is implemented.
10. A device, characterized in that: include: A memory for storing instructions; A processor is used to execute the instructions so that the device performs operations to implement the target monitoring method combining the advantages of real aperture and synthetic aperture radar as described in any one of claims 1-7.