A method for detecting space maneuvering targets using distributed radar

Abstract

The present invention discloses a method for detecting a space maneuvering target by a distributed radar. In the case of a long distance, a detection-tracking working mode is adopted to detect and continuously track the target, and provide guidance information for the target characteristic measurement; in the case of a close distance, a detection-three-dimensional imaging-tracking working mode is adopted to detect and track the target while performing instantaneous three-dimensional imaging of the target to achieve target characteristic measurement; the method of the present invention constructs a brand-new distributed array radar system architecture, obtains the same or better performance as a radar system with an ultra-large power aperture product, and has an integrated application mode of detection, tracking, imaging and recognition.

Description

Technical Field

[0001] The present invention belongs to the technical field of space target detection, and in particular relates to a method for detecting space maneuvering targets using a distributed radar. Background Art

[0002] With the increasing level of modern aerospace science and technology, space maneuvering spacecraft represented by spacecraft, space return spacecraft, and small satellite groups have brought huge challenges to the current space target measurement and perception system: on the one hand, the existing technical system is difficult to include the detection and stable tracking of high-speed maneuvering targets; on the other hand, the existing observation equipment does not have the ability to quickly image and cannot achieve dynamic measurement of target characteristics. The essential reason is that the working mode of traditional radar equipment is mostly based on time sampling of continuous pulse accumulation, while high-speed maneuvering targets are extremely sensitive to time, with large dynamics and fast fluctuations, which makes it difficult for the existing system to quickly obtain target measurement information. To this end, it is urgent to break through the limitations of existing technologies, innovate and develop non-time-sensitive radar systems with continuous detection and tracking and instantaneous imaging capabilities, and improve the perception and characteristic measurement capabilities of space targets. Summary of the invention

[0003] In view of this, the present invention provides a method for detecting space maneuvering targets using a distributed radar, which can solve the technical problem of sensing and detecting space maneuvering targets.

[0004] The technical solution for implementing the present invention is as follows:

[0005] A method for detecting space maneuvering targets by using a distributed radar adopts a detection-tracking working mode at long distances to detect and continuously track the target, and provides guidance information for target characteristic measurement; and adopts a detection-3D imaging-tracking working mode at close ranges to detect and track the target while performing instantaneous 3D imaging of the target to achieve target characteristic measurement.

[0006] Furthermore, when the target distance is greater than 500km, it is a long-distance situation, and the detection-tracking working mode is adopted; when the target distance does not exceed 500km, it is a close-range situation, and the detection-3D imaging-tracking working mode is adopted.

[0007] Furthermore, the detection-tracking working mode includes:

[0008] The distributed array radar system is used to improve the processing gain through coherent accumulation between array elements, so as to achieve target detection under low signal-to-noise ratio conditions;

[0009] Based on the distributed full-bandwidth measurement method, the distance, angle and speed information of the target are obtained to achieve target detection and tracking.

[0010] Furthermore, the detection-3D imaging-tracking working mode includes:

[0011] The one-dimensional range image of the target is obtained by using the pulse compression method;

[0012] MIMO radar combined with compressed sensing super-resolution imaging method is used to achieve three-dimensional super-resolution imaging, and the three-dimensional image of the target can be obtained by combining the one-dimensional range image of the target;

[0013] After obtaining the target three-dimensional point cloud, edge detection and feature extraction are performed on the point cloud to obtain the size and geometric structure characteristics of the target;

[0014] Utilize the target characteristic measurement information, combined with the target orbit and array position information, to achieve target attitude measurement;

[0015] By utilizing deep processing of image sequences, track association and continuous tracking of targets can be achieved in the image domain.

[0016] Furthermore, the three-dimensional resolution expression of the distributed radar is:

[0017]

[0018] Among them, ρ X , Y , Z Respectively represent the resolution in azimuth, elevation and range, κ X , κ Y Respectively represent the super-resolution multiples in azimuth and elevation, L X , L Y They represent the baseline lengths in azimuth and elevation respectively, B represents the radar signal bandwidth, C represents the speed of light, and R max represents the radar range, λ c Indicates the radar signal carrier wavelength.

[0019] Beneficial effects:

[0020] 1. The distributed radar detection method for space maneuvering targets of the present invention constructs a new distributed array radar system architecture, obtains the same or better performance as the ultra-large power aperture product radar system, and has an integrated application mode of detection, tracking, imaging and identification.

[0021] 2. The distributed radar detection method for space maneuvering targets of the present invention proposes a new technical system based on distributed array radar instantaneous super-resolution three-dimensional imaging, uses MIMO spatial sampling to replace traditional radar time sampling, and adopts sparse super-resolution and orthogonal broadband waveform technology to complete the instantaneous high-resolution three-dimensional imaging of the target within a single pulse period, so as to realize the measurement of target characteristics such as the shape, structure, and posture of the space target. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A diagram schematically shows the working mode of the distributed radar space target detection method of the present invention.

[0023] Figure 2 The working flow chart of the distributed radar of the present invention is schematically shown.

[0024] Figure 3 Schematic diagram showing the distributed radar measurement principle.

[0025] Figure 4 This is the simulation result of the instantaneous three-dimensional imaging of the distributed radar according to the embodiment of the present invention (on-orbit targets in space).

[0026] Figure 5 This is the simulation result of the instantaneous three-dimensional imaging of the distributed radar according to the embodiment of the present invention (space round-trip target). DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0028] like Figure 3 As shown, the distributed array radar system of the present invention is a system including multiple radar nodes, the core of which is a multi-phase center transceiver system composed of sparsely distributed radar antenna arrays. Multiple radar nodes work together, and the two-dimensional long baseline formed by the antenna array enables the radar system to obtain equivalent two-dimensional ultra-high angular resolution. At the same time, the space target meets the sparsity requirement relative to the cosmic space background. The compressed sensing super-resolution method can further significantly improve the angular resolution, combined with the high resolution capability of the radar system in the distance direction, so that the distributed array radar system has the ability to obtain high-resolution three-dimensional images.

[0029] The three-dimensional resolution expression of the distributed array radar measurement system is as follows:

[0030]

[0031] In formula (1), ρ X , Y , Z Respectively represent the resolution in azimuth, elevation and range, κ X , κ Y Respectively represent the super-resolution multiples in azimuth and elevation, L X , L Y They represent the baseline lengths in azimuth and elevation respectively, B represents the radar signal bandwidth, C represents the speed of light, and R max represents the radar range, λ cRepresents the wavelength of the radar signal carrier. The resolution of the distributed array radar system in azimuth and elevation is the angular resolution, which is fundamentally different from the resolution obtained by ISAR or sequential ISAR and has nothing to do with time. Therefore, the distributed array radar system theoretically has the ability to obtain high-resolution three-dimensional images of sparse targets using only a single pulse echo.

[0032] Combination Figure 1 As shown, the distributed radar detection method for space maneuvering targets of the present invention designs the task flow and working mode according to the typical application scenario of space target observation. In the case of long distance, the detection-tracking working mode is adopted to detect and continuously track the target, providing guidance information for accurate measurement of target characteristics; in the case of close distance, the detection-three-dimensional imaging-tracking working mode is adopted to detect and track the target while performing instantaneous three-dimensional imaging of the target to achieve target characteristic measurement.

[0033] Specifically, the detection-tracking mode includes: ① using the distributed array radar system to improve the processing gain through coherent accumulation between array elements to achieve target detection under low signal-to-noise ratio conditions; ② obtaining the target's distance, angle, speed and other information based on the distributed full-bandwidth measurement method to achieve target detection and tracking.

[0034] In the detection-3D imaging-tracking mode, it includes: ① using pulse compression technology to obtain the one-dimensional range image of the target; ② using MIMO radar technology combined with compressed sensing super-resolution imaging method to achieve two-dimensional super-resolution imaging, and combining with the one-dimensional range image of the target to obtain the three-dimensional image of the target; ③ after obtaining the three-dimensional point cloud of the target, the point cloud is processed by edge detection, feature extraction and other processing to obtain the size, geometric structure and other characteristics of the target; ④ using the target characteristic measurement information, combined with the target orbit and array position information, to achieve target posture measurement, tactical action extraction, and tactical intention judgment; ⑤ using the target posture information combined with the sequence three-dimensional transient imaging results, perform image sequence depth correlation processing to achieve target track association and continuous tracking from the image domain.

[0035] The task flow and working mode are designed according to the typical application scenarios of the radar system. The typical application scenario of the radar system is: the radar system is deployed at a designated position as ground monitoring equipment in the test of the near-space aircraft target range of the party, and performs detection, tracking, three-dimensional imaging and target characteristic measurement on the space aircraft entering the radar detection range. During the operation of the radar system, the distance between the target and the radar changes from far to near and from near to far according to the existence of the system. The radar system should be able to meet the measurement requirements of the entire process. The radar system is designed with two working modes according to different ranges of action, namely:

[0036] Detection-tracking mode: For detection scenarios with a target distance range of >500km, the distributed array radar system uses broadband signals to conduct distributed detection of targets in the specified airspace, and continuously tracks the targets after detection. During this period, the target distance, speed, and angle are measured;

[0037] Detection-3D imaging-tracking mode: For detection scenarios with a target distance range of ≤500km, the radar system adds a 3D imaging-tracking process based on the detection-tracking mode process. The two processes are processed in parallel, and the output of the 3D imaging-tracking process is used as the highest priority for distributed array radar beam control. During this period, transient 3D imaging of the target, image-based target tracking, target distance, speed, angle, size, geometry, and real-time attitude measurement are performed.

[0038] The specific process is as follows Figure 2 As shown, first the radar system is turned on, the antenna beam angle is set according to the target entry position, the system enters the detection-tracking mode and starts detection, detects the target and switches to tracking, and outputs parameters such as target distance, speed and angle. Then the phased array antenna beam pointing and mechanical servo pointing are adjusted in real time according to the target position to ensure that the target is continuously within the radar beam range. When the target distance is within 500km, the detection-3D imaging-tracking mode is entered and detection is started, and the target distance, speed, angle and 3D image are output in real time. The phased array antenna beam pointing and mechanical servo pointing are adjusted in real time according to the target position to ensure that the target is continuously within the radar beam range. When the target distance exceeds 500km, the detection and tracking mode is entered and detection is started, and the target distance, speed and angle are output in real time. The phased array antenna beam pointing and mechanical servo pointing are adjusted in real time according to the target position to ensure that the target is continuously within the radar beam range. When the target distance exceeds 1000km, the radar system stops detection and the radar system is shut down.

[0039] Example

[0040] Figure 4 and Figure 5 The distributed radar has an operating range of 500 km, a carrier frequency of 10 GHz, a bandwidth of 1 GHz, a 5-transmitter 25-receiver planar array configuration, a target speed of 10 Mach, and uses a single pulse to reconstruct the three-dimensional scattering points of space on-orbit vehicles and space round-trip vehicle targets.

[0041] from Figure 4 and Figure 5 It can be seen from the figure that the method of the present invention performs edge detection, feature extraction and other processing on the target three-dimensional image. Even when a small number of three-dimensional scattering points are obtained, the target characteristics such as target size, structure and posture can still be extracted from it, which is feasible.

[0042] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting a space maneuvering target using a distributed radar, characterized in that: In long-distance situations, the detection-tracking working mode is adopted to detect and continuously track the target, providing guidance information for target characteristic measurement; in close-range situations, the detection-3D imaging-tracking working mode is adopted to detect and track the target while performing instantaneous 3D imaging of the target to achieve target characteristic measurement; When the target distance is greater than 500km, it is a long-distance situation and the detection-tracking working mode is adopted; When the target distance does not exceed 500km, it is considered a close-range situation and the detection-3D imaging-tracking working mode is adopted; The detection-tracking operating modes include: The distributed array radar system is used to improve the processing gain through coherent accumulation between array elements, so as to achieve target detection under low signal-to-noise ratio conditions; Based on the distributed full-bandwidth measurement method, the distance, angle and speed information of the target are obtained to achieve target detection and tracking; The detection-3D imaging-tracking working modes include: The one-dimensional range image of the target is obtained by using the pulse compression method; MIMO radar combined with compressed sensing super-resolution imaging method is used to achieve three-dimensional super-resolution imaging, and the three-dimensional image of the target can be obtained by combining the one-dimensional range image of the target; After obtaining the target three-dimensional point cloud, edge detection and feature extraction are performed on the point cloud to obtain the size and geometric structure characteristics of the target; Utilize the target characteristic measurement information, combined with the target orbit and array position information, to achieve target attitude measurement; By utilizing deep processing of image sequences, track association and continuous tracking of targets can be achieved in the image domain.

2. A method for detecting a space maneuvering target using a distributed radar as claimed in claim 1, characterized in that: The three-dimensional resolution expression of distributed radar is: Among them, ρ X , Y , Z Respectively represent the resolution in azimuth, elevation and range, κ X , κ Y Respectively represent the super-resolution multiples in azimuth and elevation, L X , L Y They represent the baseline lengths in azimuth and elevation, B represents the radar signal bandwidth, C represents the speed of light, and R max represents the radar range, λ c Indicates the radar signal carrier wavelength.

Images