Active coherent optical synthetic aperture super-resolution imaging space target surveillance system

Abstract

The application discloses a kind of active coherent optical synthetic aperture super-resolution imaging space target monitoring systems, including active coherent light generation module, optical imaging module, image super-resolution reconstruction module, power module, motion control module and heat dissipation module.Active coherent light generation module is constituted by laser and optical phased array, optical imaging module is constituted by front end optics and surface array detector, image super-resolution reconstruction module is constituted by GPU and super-resolution reconstruction software.Laser provides light source for optical phased array, optical phased array irradiates light source to target, and front end optics receives target reflected light, and forms low-resolution image on surface array detector.Image super-resolution reconstruction module carries out pre-processing and super-resolution reconstruction to low-resolution image.Power module provides power supply for other modules.Motion control module is used to control system to realize aiming tracking, and heat dissipation module is used for laser cooling.The application can realize 4-8 times equivalent aperture super-resolution imaging.

Description

Technical Field

[0001] This invention relates to an active coherent optical synthetic aperture super-resolution imaging space target surveillance system, which is suitable for space-based space target surveillance imaging. Technical Background

[0002] Researching new space-based target surveillance systems to acquire information on target structure, geometry, attitude, and operational status, and to construct a space target detection, identification, and information transmission system to achieve target classification and identification, and infer target tactical intentions, is of great significance for ensuring my country's space security. GEO-orbiting satellites mainly include communication and broadcasting satellites, data relay satellites, missile early warning satellites, and radio reconnaissance satellites. Their dimensions range from 1.5m to 3m in length and width, and from 2m to 8.5m in height. Their solar panels or antennas are generally on the order of meters to hundreds of meters. Furthermore, the dynamic range of the illuminated and shadowed surfaces of GEO-orbiting space targets is large, leading to imaging problems in the Earth's shadow area. Additionally, there are periods of backlighting during global patrols, which can easily create surveillance loopholes.

[0003] Ground-based telescopes and ground-based radars have insufficient imaging capabilities for geostationary orbit (GEO) targets and cannot achieve full coverage of the GEO zone. Existing traditional passive large-aperture optical space target surveillance payloads lack high-resolution detection capabilities for weak targets and cannot meet nighttime imaging requirements. They also face development difficulties and limitations in carrying capacity due to the need to further increase the aperture.

[0004] While passive space target surveillance systems using universal mirrors can achieve field-of-view scanning and continuous locking and tracking, they suffer from slow scanning speed and low scanning accuracy. Passive synthetic aperture imaging technology based on mirror splicing can avoid the difficulties of processing ultra-large aperture, high-precision optical mirrors, but its co-phase adjustment requires high precision and is difficult to implement in engineering.

[0005] Currently, active coherent optical synthetic aperture (APSAP) imaging technology based on Fourier transform stacking has expanded from the microscopic field to the macroscopic imaging field, undergoing development in both transmission and reflection modes. Research in this field is mostly concentrated in the visible band, with little research on near-infrared APSAP super-resolution imaging technology specifically designed for nighttime imaging needs.

[0006] The Fourier layered spectrum scanning methods mainly include light source scanning, camera scanning, and aperture scanning. Among them, the method of using a light source mounted on an XYZ displacement stage to achieve multi-angle illumination is more suitable for microscopic imaging, but it suffers from slow scanning speed and low accuracy for macroscopic applications. Although the method of using spatial light modulators and microlens arrays to generate multi-angle illumination can solve the problems of light source intensity drift and intensity non-uniformity, it is still currently limited to microscopic applications. Macroscopic transmission-type active coherent optical synthetic aperture systems using camera scanning require frequent payload movement, rapid attitude adjustment, and high-precision positioning, resulting in extremely high energy consumption, high requirements for platform control precision, and long scanning time, making them unsuitable for space-based target surveillance scenarios. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of existing technologies and propose an active coherent optical synthetic aperture super-resolution imaging space target surveillance system to solve problems related to nighttime imaging, backlighting, and imaging in shadow areas. Through reasonable orbit design and orbital maneuvers, high-resolution, all-weather imaging of space targets is achieved using active coherent optical super-resolution imaging technology. This allows for the identification and classification of key targets and, as needed, long-term surveillance of certain non-cooperative targets.

[0008] The above-mentioned objective of the present invention is achieved through the following technical solution:

[0009] An active coherent optical synthetic aperture super-resolution imaging space target surveillance system includes: an active coherent light generation module, an optical imaging module, an image super-resolution reconstruction module, and a motion control module.

[0010] The active coherent light generation module includes a laser and an optical phased array; the optical imaging module includes a front-end optical module and an area array detector.

[0011] The laser provides a laser beam to the optical phased array, which illuminates the space target with the laser beam at a certain angle. The front-end optical module receives the reflected light from the space target and forms a low-resolution image on the array detector. The image super-resolution reconstruction module preprocesses and reconstructs the low-resolution image. The motion control module is used to achieve aiming and tracking.

[0012] Furthermore, it also includes a heat dissipation module and a power supply module; the power supply module provides power to other modules, and the heat dissipation module is used to dissipate heat from the laser.

[0013] Furthermore, the optical phased array includes an optical fiber array, a multimode interference beam splitter, a phase shifter, a grating diffraction array output waveguide, and a drive controller;

[0014] The fiber optic array couples the laser beam into the multimode interference beam splitter. The multimode interference beam splitter divides the laser beam into N paths in a cascaded manner and connects to the N waveguide array elements in the phase shifter. The drive controller applies different voltages to the electrodes on the N waveguide array elements, causing a temperature difference between adjacent waveguide array elements. A phase difference is generated between adjacent waveguide array elements through the thermo-optic effect of the waveguide array elements.

[0015] The light beams with a certain phase difference are output by the output waveguide of the grating diffraction array and coherently superposed in the far field, and output at a certain angle. The number of output light beam paths is N×N. Each light beam points to a spatial target and evenly covers the entire imaging field of view, and realizes the uniform scanning of the target by the light beam along the designed "zigzag" path under the control of a computer program. The uniform scanning speed is

[0016] Furthermore, the optical phased array further includes a system position feedback corrector.

[0017] When the active coherent optical synthetic aperture super-resolution imaging spatial target surveillance system operates at an orbital altitude different from the target, there will be a certain relative motion speed. At this time, the optical phased array also has the same relative motion speed. The system position feedback corrector feeds back the relative motion speed of the optical phased array to the drive controller in real time, and the drive controller adjusts the actual scanning speed of the light beam to the target to Finally, under the combined action of the orbital relative motion and the actual scanning, it is to achieve real-time correction of the light beam scanning speed and pointing position.

[0018] Furthermore, the front-end optical module includes a polarizer, a narrow-band filter, and an imaging lens.

[0019] When the highly coherent laser beam irradiates the rough surface of the spatial target, the wavefront phase of the generated coherent reflected light field is randomly modulated. The background stray light outside the working spectral band is filtered by the polarizer and the narrow-band filter, and is received by the imaging lens and forms a low-resolution initial image with a randomly distributed speckle pattern on the area array detector.

[0020] Furthermore, the laser provides a high-power, high-coherence near-infrared laser beam for the fiber optic array in the optical phased array.

[0021] Furthermore, the image super-resolution reconstruction module realizes the preprocessing of noise reduction and position calibration of the initial image on the GPU through super-resolution reconstruction software, and performs super-resolution reconstruction through the Fourier ptychography constrained spectral stitching algorithm integrated in the super-resolution reconstruction software to obtain an image with the equivalent synthetic aperture resolution.

[0022] Furthermore, the active coherent optical synthetic aperture super-resolution imaging space target monitoring system realizes two working modes: global inspection mode and regional inspection mode for GEO orbit targets.

[0023] The global patrol mode refers to the active coherent optical synthetic aperture super-resolution imaging space target surveillance system operating below the GEO orbit, typically at a GEO-150km orbit, achieving capture, tracking, imaging, and surveillance of targets in the global GEO zone through relative drift of the tandem position.

[0024] The regional patrol mode refers to the use of the altitude difference with the GEO orbit to form forward drift, backward drift, and ascent and descent orbit movements to form a round trip patrol of a designated area, so as to achieve target acquisition, tracking, and imaging observation within the corresponding area.

[0025] Furthermore, when using the global patrol mode, the active coherent optical synthetic aperture super-resolution imaging space target surveillance system is in a GEO-150km orbit, drifting forward relative to the target and pointing towards the deep space background, which can obtain detailed images of the main payload carried by the target.

[0026] During this phase, the relative velocity of the active coherent optical synthetic aperture super-resolution imaging space target surveillance system to the GEO orbit target is 3.62 m / s, slightly faster than the target star; during the prograde drift phase, the actual scanning speed of the beam during co-directional scanning is... The actual scanning speed of the beam during reverse scanning is in, The uniform scanning speed of the beam on the target. The relative velocity of an active coherent optical synthetic aperture super-resolution imaging space target surveillance system with respect to a target in a GEO orbit at a distance of 150 km is given.

[0027] Furthermore, when using the regional inspection mode, it goes through four stages: forward drift, backward drift, and orbital ascent and descent.

[0028] The calculation of the actual beam scanning speed during the forward drift phase is the same as that using the global inspection mode;

[0029] During the recession drift phase, the Active Coherent Optical Synthetic Aperture Super-Resolution Imaging Space Target Surveillance System is in a GEO+150km orbit, pointing towards the Earth background. At this time, the morphology of the target can be observed from the side and above. During this phase, the relative motion velocity of the Active Coherent Optical Synthetic Aperture Super-Resolution Imaging Space Target Surveillance System with respect to the GEO orbit target is -3.61m / s, which is slightly slower than the target star.

[0030] During the recession drift phase, the actual scanning speed of the beam during co-directional scanning is: The actual scanning speed of the beam during reverse scanning is in, The uniform scanning speed of the beam on the target. The relative velocity of the active coherent optical synthetic aperture super-resolution imaging space target surveillance system with respect to the target in the GEO orbit when it is in a GEO+150km orbit.

[0031] During the ascent and descent process in the area survey mode, the actual scanning speed of the beam is: It remains the uniform scanning speed of the beam on the target.

[0032] The beneficial effects of this invention compared to the prior art are:

[0033] (1) The present invention uses near-infrared laser active illumination, which is not affected by sunlight and can meet the needs of active imaging at night, realizing all-day monitoring and imaging of space targets; it can effectively solve the problem of imaging in the shadow area and solve the problem of backlight imaging monitoring loopholes.

[0034] (2) This invention applies high-precision, fast optical phased array beam scanning technology and system position feedback correction technology to active coherent optical synthetic aperture system; optical phased array beam scanning technology has the advantages of miniaturization and integration, with a large scanning angle, fast speed, high pointing accuracy and good controllability, which can effectively improve the scanning accuracy and timeliness of the spectrum of space targets.

[0035] (3) The system position feedback corrector used in this invention can correct the beam direction of the optical phased array output in real time, ensuring that the coherent beam scans the space target at a uniform speed.

[0036] (4) The front-end optics of this invention use polarizers and narrowband filters, which can effectively filter out background stray light outside the working spectrum and improve the signal-to-noise ratio of low-resolution images.

[0037] (5) The present invention uses a small aperture optical imaging module to acquire low-resolution image sequences of different spectrums of the target, and reconstructs a super-resolution image with a near equivalent synthetic aperture ratio through Fourier stacked spectrum stitching algorithm. This not only greatly reduces the aperture requirement, but also effectively improves the target detection probability and recognition accuracy.

[0038] (6) The near-infrared laser source adopted by the present invention needs to cover the entire imaging field of view. To ensure the energy density of coherent light at the entrance pupil of the optical system, if a 0.5m aperture optical imaging module is used to achieve a 520m width and a 0.1m resolution through 5-fold super-resolution, the laser power is required to reach about the order of hundreds of watts. Therefore, the application of the present invention depends on the development of future miniaturized high-power space-based lasers. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of the architecture of the active coherent optical synthetic aperture super-resolution imaging space target monitoring system of the present invention;

[0040] Figure 2 is a schematic diagram of the composition of the optical phased array of the present invention;

[0041] Figure 3 is a working mode diagram of the active coherent optical synthetic aperture super-resolution imaging space target monitoring system of the present invention;

[0042] Figure 4 is a schematic diagram showing that each beam output by the optical phased array of the present invention points to the target and covers the imaging field of view;

[0043] Figure 5 is a schematic diagram of the velocity relationship in the prograde drift stage of the present invention;

[0044] Figure 6 is a schematic diagram of the velocity relationship in the retrograde drift stage of the present invention;

[0045] Figure 7 is a schematic diagram showing that the beams output by the optical phased array of the present invention perform uniform scanning on the space target in a "zigzag" shape. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The following further describes the present invention in detail with reference to the Figure 1-7 drawings and specific embodiments.

[0047] The present invention provides an active coherent optical synthetic aperture super-resolution imaging space target monitoring system, which is mainly used for active all-day and all-night monitoring imaging of space targets in space.

[0048] As Figure 1 shown is an active coherent optical synthetic aperture super-resolution imaging space target monitoring system of the present invention. It mainly consists of an active coherent light generation module, an optical imaging module, an image super-resolution reconstruction module, a power supply module, a motion control module, and a heat dissipation module. The active coherent light generation module includes a laser and an optical phased array. The optical imaging module includes a front-end optical module and a planar array detector.

[0049] The laser provides a laser beam for the optical phased array. The optical phased array irradiates the laser beam at a certain angle onto a space target. The front-end optical module receives the reflected light from the space target and forms a low-resolution image on the area array detector. The image super-resolution reconstruction module preprocesses and super-resolves the low-resolution image. The motion control module is used to achieve aiming and tracking. The power supply module provides power for other modules, and the heat dissipation module is used for laser heat dissipation.

[0050] As Figure 2 shown, the optical phased array includes an optical fiber array, a multimode interference beam splitter, a phase shifter, a grating diffraction array output waveguide, a drive controller, and a system position feedback corrector.

[0051] The optical fiber array couples the laser beam into the multimode interference beam splitter. The multimode interference beam splitter divides the laser beam into N paths in a cascaded manner and connects to the N waveguide array elements in the phase shifter. The drive controller applies different voltages to the electrodes on the N waveguide array elements, causing a temperature difference between adjacent waveguide array elements. Through the thermo-optic effect of the waveguide array elements, a phase difference is generated between adjacent waveguide array elements.

[0052] The beams with a certain phase difference are output by the grating diffraction array output waveguide and coherently superposed in the far field, output at a certain angle. The number of output beam paths is N×N paths. Each beam path points to the space target and evenly covers the entire imaging field of view. Under the control of a computer program, the beams scan the target at a constant speed along the designed "zigzag" path. The constant scanning speed is The drive controller receives the information fed back by the system position feedback corrector according to the motion speed of the satellite platform and real-time corrects the scanning speed of the scanning beam.

[0053] When the active coherent optical synthetic aperture super-resolution imaging space target monitoring system operates at a different orbital altitude from the target, there will be a certain relative motion speed. At this time, the optical phased array also has the same relative motion speed. The system position feedback corrector feeds back the relative motion speed of the optical phased array to the drive controller in real time. The drive controller adjusts the actual scanning speed of the beam to the target to Finally, under the combined action of the orbital relative motion and the actual scanning, at real-time correction of the scanning speed and pointing position of the beam is achieved.

[0054] The front-end optical module includes a polarizer, a narrowband filter, and an imaging lens.

[0055] When a highly coherent laser beam illuminates the rough surface of a space target, the wavefront phase of the resulting coherent reflected light field is randomly modulated. After being filtered by a polarizer and a narrowband filter to remove background stray light outside the working spectrum, the light is received by the imaging lens and forms a low-resolution initial image with an irregularly distributed speckle pattern on the area array detector.

[0056] Lasers provide high-power, highly coherent near-infrared laser beams for fiber arrays in optical phased arrays.

[0057] The image super-resolution reconstruction module performs noise reduction and position calibration preprocessing on the GPU using super-resolution reconstruction software, and then performs super-resolution reconstruction using the Fourier stacked constrained spectrum stitching algorithm integrated within the super-resolution reconstruction software to obtain an image with equivalent synthetic aperture resolution.

[0058] like Figure 3 As shown, when the active coherent optical synthetic aperture super-resolution imaging space target monitoring system provided by the present invention is operating in global or regional patrol mode, taking the selected application scenario of detecting GEO orbit space targets in a GEO±150km orbit as an example.

[0059] The present invention, an active coherent optical synthetic aperture super-resolution imaging space target monitoring system, utilizes key target information provided by large field-of-view search imaging to achieve two working modes: global and regional inspection of GEO orbit targets, through orbital maneuvering, orbital drift, and platform steering mechanisms.

[0060] The first global patrol mode refers to the active coherent optical synthetic aperture super-resolution imaging space target surveillance system operating below the GEO orbit, typically at a GEO-150km orbit, achieving capture, tracking, imaging, and surveillance of targets in the global GEO zone through relative drift of the tandem position.

[0061] The second type of regional patrol mode refers to using the altitude difference with the GEO orbit to form forward drift, backward drift, and ascent and descent orbit movements to form a round trip patrol of a designated area, thereby achieving target acquisition, tracking, and imaging observation within the corresponding area.

[0062] In the process of an active coherent optical synthetic aperture (APSAP) super-resolution imaging space target monitoring system operating at different orbital altitudes with the target, the velocity difference causes relative motion between the system and the target. To ensure uniform scanning of the target by the coherent beam, a system position feedback corrector is needed to determine the relationship between the actual scanning speed of each beam, the uniform scanning speed, and the relative orbital velocity. The beam direction is corrected in real time.

[0063] like Figure 5As shown, when the global patrol mode is adopted, the active coherent optical synthetic aperture super-resolution imaging space target surveillance system is in a GEO-150km orbit, drifting in tandem with the target and pointing towards the deep space background, which can obtain a detailed image of the main payload carried by the target.

[0064] During this phase, the relative velocity of the active coherent optical synthetic aperture super-resolution imaging space target surveillance system to the GEO orbit target is 3.62 m / s, slightly faster than the target star; during the prograde drift phase, the actual scanning speed of the beam during co-directional scanning is... The actual scanning speed of the beam during reverse scanning is in, The uniform scanning speed of the beam on the target. The relative velocity of an active coherent optical synthetic aperture super-resolution imaging space target surveillance system with respect to a target in a GEO orbit at a distance of 150 km is given.

[0065] When using the regional inspection mode, it goes through four stages: forward drift, backward drift, and orbital ascent and descent.

[0066] The calculation of the actual scanning speed of the beam during the forward drift phase is the same as that of the previous phase. Figure 4 As shown.

[0067] During the recession drift phase, the Active Coherent Optical Synthetic Aperture Super-Resolution Imaging (ACTAS) space target surveillance system is in a GEO+150km orbit, pointing towards the Earth background. At this stage, the target's upper-side morphology can be observed. However, the blue light scattered by the Earth's atmosphere creates a strong background, so filtering out this background is necessary during this phase. The relative velocity of the ACTAS to the GEO-orbiting target during this phase is approximately -3.61 m / s, slightly slower than the target star.

[0068] like Figure 6 As shown, during the recession drift phase, the actual scanning speed of the beam during co-directional scanning is... The actual scanning speed of the beam during reverse scanning is in, The uniform scanning speed of the beam on the target. The relative velocity of the active coherent optical synthetic aperture super-resolution imaging space target surveillance system with respect to the target in the GEO orbit when it is in a GEO+150km orbit.

[0069] During the ascending and descending orbits in the area patrol mode, the actual scanning speed of the beam is still the uniform scanning speed of the beam with respect to the target.

[0070] In addition, after determining the key target of concern, it is also possible to maneuver to the range of -50 to -20 km of the GEO orbit to conduct close reconnaissance on the key target.

[0071] In both working modes, a macroscopically reflective near-infrared active coherent optical synthetic aperture super-resolution imaging space target monitoring system proposed by the present invention is adopted. A high-power and high-coherence near-infrared laser beam is generated by a laser, and after being coupled by an optical fiber array and split by a multimode interference beam splitter, under the control of a computer program, a certain fixed phase difference is generated between adjacent waveguide array elements through a phase shifter, and finally coherent superposition is achieved in a grating diffraction array, and the beam is directed at a certain angle to a space target.

[0072] As Figure 4 shown, according to the super-resolution reconstruction magnification, overlap rate, and scanning step size, the number of output beam paths is designed to be N×N paths. Each beam path is directed at the space target and evenly covers the entire imaging field of view, and the scanning of the beam is achieved according to the designed path under the control of a computer program.

[0073] According to the principle of active coherent optical super-resolution imaging, when the pointing angle of the coherent beam changes, the target spectrum collected by the optical imaging module will undergo a corresponding displacement. Coherent beam scanning is achieved through an optical phased array. A single small-aperture optical imaging module collects a sequence of low-resolution images of different target spectra, and then super-resolution reconstruction of the low-resolution images is performed.

[0074] The specific steps are as follows:

[0075] a. If an optical imaging module with an aperture of D is used to achieve 5-fold super-resolution and the overlap rate of the target spectra collected by the optical imaging module twice adjacent times is set to 60%, then the single-step displacement of the target spectrum is equal to the spectral width corresponding to 0.4D aperture;

[0076] b. As Figure 7 shown, continuously change the beam pointing angle and scan the space target in a "zigzag" shape at a speed to collect a sequence of 11×11 low-resolution images at different spectral positions, which can cover all the spectra corresponding to the 5-fold super-resolution image;

[0077] c. Perform preprocessing such as noise reduction and position calibration on the sequence of low-resolution images on the GPU in the image super-resolution reconstruction module using super-resolution reconstruction software;

[0078] d. A super-resolution target image with an equivalent synthetic aperture magnification of nearly 5 times was reconstructed using the Fourier stacked constrained spectrum stitching algorithm integrated within the super-resolution reconstruction software.

[0079] In such Figure 3 In the global or regional patrol mode shown, repeat the above bd steps to achieve continuous monitoring of space targets.

[0080] The above description is only used to illustrate the technical solution of the present invention and is not intended to limit it. Any other modifications, equivalent substitutions or improvements made by those skilled in the art to the technical solution of the present invention, as long as they do not depart from the spirit and scope of the technical solution of the present invention, should be covered within the scope of the claims of the present invention.

[0081] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. An active coherent optical synthetic aperture super-resolution imaging space object surveillance system, characterized in that include: Active coherent light generation module, optical imaging module, image super-resolution reconstruction module, and motion control module; The active coherent light generation module includes a laser and an optical phased array; the optical imaging module includes a front-end optical module and an area array detector. The laser provides a laser beam to the optical phased array, which illuminates the space target with the laser beam at a certain angle. The front-end optical module receives the reflected light from the space target and forms a low-resolution image on the array detector. The image super-resolution reconstruction module preprocesses and reconstructs the low-resolution image. The motion control module is used to achieve aiming and tracking. The optical phased array includes an optical fiber array, a multimode interference beam splitter, a phase shifter, a grating diffraction array output waveguide, and a drive controller; the optical fiber array couples a laser beam into the multimode interference beam splitter, and the multimode interference beam splitter divides the laser beam into N paths in a cascaded manner and connects them to the N waveguide array elements in the phase shifter. The drive controller applies different voltages to the electrodes on the N waveguide array elements, causing a temperature difference between adjacent waveguide array elements. Through the thermo-optic effect of the waveguide array elements, a phase difference is generated between adjacent waveguide array elements; the beams with a certain phase difference are output by the grating diffraction array output waveguide and coherently superposed in the far field, and are output at a certain angle. The number of output beam paths is N×N paths, and each beam path points to a spatial target and uniformly covers the entire imaging field of view. Under the control of a computer program, the beam scans the target at a constant speed along the designed "ji" - shaped path, and the constant scanning speed is ; The optical phased array also comprises a system position feedback corrector; when the active coherent optical synthetic aperture super-resolution imaging space target monitoring system operates at different orbital altitudes from the target, it has a certain relative motion speed At this time, the optical phased array also has the same relative motion speed ; System position feedback corrector corrects the relative motion speed of the optical phased array in real time to the driving controller, which adjusts the actual scanning speed of the light beam to the target , ; finally, under the joint action of the relative motion of the track and the actual scanning , the real-time correction of the scanning speed and pointing position of the light beam is realized.

2. The active coherent optical synthetic aperture super-resolution imaging space object monitoring system according to claim 1, characterized in that: It also includes a heat dissipation module and a power supply module; the power supply module provides power to other modules, and the heat dissipation module is used to dissipate heat from the laser.

3. An active coherent optical synthetic aperture super-resolution imaging space object monitoring system according to claim 1, characterized in that: The front-end optical module includes a polarizer, a narrowband filter, and an imaging lens; When a highly coherent laser beam illuminates the rough surface of a space target, the wavefront phase of the resulting coherent reflected light field is randomly modulated. After being filtered by a polarizer and a narrowband filter to remove background stray light outside the working spectrum, the light is received by the imaging lens and forms a low-resolution initial image with an irregularly distributed speckle pattern on the area array detector.

4. An active coherent optical synthetic aperture super-resolution imaging space object monitoring system according to claim 1, characterized in that: Lasers provide high-power, highly coherent near-infrared laser beams for fiber arrays in optical phased arrays.

5. An active coherent optical synthetic aperture super resolution imaging space object monitoring system according to claim 1, characterized in that: The image super-resolution reconstruction module performs noise reduction and position calibration preprocessing on the GPU using super-resolution reconstruction software, and then performs super-resolution reconstruction using the Fourier stacked constrained spectrum stitching algorithm integrated within the super-resolution reconstruction software to obtain an image with equivalent synthetic aperture resolution.

6. An active coherent optical synthetic aperture super resolution imaging space object monitoring system according to claim 1, characterized in that: The active coherent optical synthetic aperture super-resolution imaging space target monitoring system realizes two working modes: global inspection mode and regional inspection mode for GEO orbit targets. The global patrol mode refers to the active coherent optical synthetic aperture super-resolution imaging space target surveillance system operating below the GEO orbit, typically at a GEO-150km orbit, achieving capture, tracking, imaging, and surveillance of targets in the global GEO zone through relative drift of the tandem position. The regional patrol mode refers to the use of the altitude difference with the GEO orbit to form forward drift, backward drift, and ascent and descent orbit movements to form a round trip patrol of a designated area, so as to achieve target acquisition, tracking, and imaging observation within the corresponding area.

7. An active coherent optical synthetic aperture super resolution imaging space object monitoring system according to claim 6, characterized in that: When using the global survey mode, the active coherent optical synthetic aperture super-resolution imaging space target surveillance system is in a GEO-150km orbit, drifting forward relative to the target and pointing towards the deep space background, which can obtain detailed images of the main payload carried by the target. During this phase, the relative velocity of the active coherent optical synthetic aperture super-resolution imaging space target surveillance system to the GEO orbit target is 3.62 m / s, slightly faster than the target star; during the prograde drift phase, the actual scanning speed of the beam during co-directional scanning is... The actual scanning speed of the beam during reverse scanning is , ;in, The uniform scanning speed of the beam on the target. The relative velocity of an active coherent optical synthetic aperture super-resolution imaging space target surveillance system with respect to a target in a GEO orbit at a distance of 150 km is given. .

8. An active coherent optical synthetic aperture super resolution imaging space object monitoring system according to claim 6, characterized in that: When using the regional inspection mode, it goes through four stages: forward drift, backward drift, and orbital ascent and descent. The calculation of the actual beam scanning speed during the forward drift phase is the same as that using the global inspection mode; During the recession drift phase, the active coherent optical synthetic aperture super-resolution imaging space target surveillance system is in GEO+150km orbit, pointing towards the Earth background, at which time the morphology of the target can be observed from the side and above. During this phase, the relative velocity of the active coherent optical synthetic aperture super-resolution imaging space target surveillance system with respect to the GEO orbit target is -3.61 m / s, which is slightly slower than the target star. In the retrograde drift phase, the actual scanning speed of the light beam is , , in the reverse scanning, the actual scanning speed of the light beam is , ; wherein, is the uniform scanning speed of the light beam to the target, is the relative motion speed of the active coherent optical synthetic aperture super-resolution imaging space target monitoring system relative to the GEO orbit target when in the GEO+150km orbit, ; In the process of ascending and descending the orbit in the area patrol mode, the actual scanning speed of the light beam is , , It is still the uniform scanning speed of the light beam to the target.

Images