Small space-based polarization super-lens camera and imaging method

Abstract

The invention discloses a small space-based polarization super-lens camera and an imaging method, the small space-based polarization super-lens camera comprises a shading assembly, polarization super-lens assemblies, an imaging system and a heat dissipation assembly which are arranged on a camera shell, the two polarization super-lens assemblies are arranged according to the light path direction, and the shading assembly is arranged in front of the polarization super-lens assemblies according to the light path direction; the imaging system is arranged behind the polarization super-lens assembly according to the light path direction, and the heat dissipation assembly is used for conducting heat adjustment on the imaging system. The polarization super-lens camera is installed on a supporting rod of a spacecraft and serves as a main optical system to be applied to on-orbit self-detection service, and the advantages of being small in size, light in weight, high in reconstruction efficiency and the like are achieved. The two groups of polarization super lens assemblies can form two groups of orthogonal polarization sub-images on an image plane at one time, that is, four polarization sub-images of a target can be obtained through one-time shooting of a camera, and three-dimensional reconstruction is carried out in real time; the heat dissipation assembly can achieve on-orbit low-temperature storage and effective work of the polarization super-lens camera.

Description

Technical Field

[0001] This invention generally relates to the field of spacecraft technology, and more specifically, to a small space-based polarizing superlens camera and imaging method. Background Technology

[0002] Lacking an atmosphere for protection, spacecraft face numerous potential threats in outer space. Particularly during orbital operation, manned spacecraft such as space stations frequently encounter impact risks from micrometeoroids, debris from defunct satellites, and rocket final stages. Even small debris can cause severe damage to the spacecraft's external structure, solar panels, and other critical components. In deep space exploration missions, the vast distances and communication delays make it difficult for ground control centers to detect and respond to these emergencies in a timely manner.

[0003] Therefore, modern spacecraft must possess comprehensive autonomous detection capabilities to monitor their own status in real time, facilitating ground personnel to identify the location and extent of damage. This not only provides precise data for subsequent on-orbit maintenance and component replacement operations but also forms the crucial technological foundation for conducting complex on-orbit services such as active debris removal, refueling, and equipment upgrades, ensuring the long-term stable operation of spacecraft in the harsh space environment. Summary of the Invention

[0004] To address the above technical problems, this invention provides a small space-based polarizing superlens camera and imaging method.

[0005] According to a first aspect of the present invention, a small space-based polarizing superlens camera is provided, comprising a light-shielding component, a polarizing superlens component, an imaging system, and a heat dissipation component disposed on a camera housing. The polarizing superlens component is arranged in two groups according to the optical path direction. The light-shielding component is disposed in front of the polarizing superlens component according to the optical path direction, and the imaging system is disposed behind the polarizing superlens component according to the optical path direction. The heat dissipation component is used to regulate the heat of the imaging system.

[0006] According to some embodiments of the present invention, the polarizing superlens assembly includes a mirror chamber, a threaded gasket, and a lens body. The mirror chamber is provided with an internal thread, and the threaded gasket is threadedly connected to the mirror chamber via the internal thread. The lens body is disposed on the threaded gasket, and the position of the lens body in the optical axis direction is adjusted by the threaded gasket.

[0007] According to some embodiments of the present invention, the heat dissipation component includes an internal heat dissipation component and an external heat dissipation component. The internal heat dissipation component is disposed inside the camera housing, and the external heat dissipation component is disposed outside the camera housing. The heat of the imaging system is conducted to the external environment through the internal heat dissipation component and the external heat dissipation component.

[0008] According to some embodiments of the present invention, the internal heat dissipation assembly includes a CMOS heat sink, a timing drive heat sink, a power supply heat sink, and inner plate screws; the imaging system includes a CMOS detector imaging board, a timing drive circuit board, and a power supply board; the CMOS heat sink, CMOS detector imaging board, timing drive circuit board, timing drive heat sink, power supply board, and power supply heat sink are sequentially stacked; and the CMOS heat sink and the CMOS detector imaging board are attached together, the timing drive heat sink is attached to the timing drive circuit board, and the power supply heat sink is attached to the power supply board; the CMOS heat sink, timing drive heat sink, and power supply heat sink are fixedly connected to the inside of the camera housing by the inner plate screws.

[0009] According to some embodiments of the present invention, the inner plate screw includes a screw head and a screw cap, the screw head having a threaded inner hole that matches the thread of the screw head, and two adjacent sets of inner plate screws are connected by the screw head and screw cap to form an integral heat-conducting structure.

[0010] According to some embodiments of the present invention, the external heat dissipation assembly includes a first external heat dissipation plate and a second external heat dissipation plate, which are mounted on both sides of the camera housing by screws.

[0011] According to some embodiments of the present invention, the CMOS detector imaging board includes two CMOS image sensors, and the CMOS detector imaging board is used to perform photoelectric conversion.

[0012] According to some embodiments of the present invention, the timing drive circuit board is used to perform functions such as configuring the CMOS image sensor, controlling the transmission of image acquisition commands, transmitting image data, and external communication.

[0013] According to some embodiments of the present invention, the power board includes a power supply and an interface chip, and the power board is used to perform functions such as power supply and level conversion.

[0014] According to a second aspect of the present invention, a method for imaging a small space-based polarizing superlens is provided, comprising the following steps: S100: Wiener filtering and Gaussian filtering are used to enhance the images acquired by the small space-based polarizing superlens camera; S200: The two acquired images are segmented based on the focal position to obtain four independent polariton images at 0°, 90°, 45°, and 135°. S300: Employs an image alignment method based on Fast Fourier Transform to achieve spatial registration of images of each polarizer; S400: Calculate the phase angle φ and polarization degree ρ of the diffuse reflected light from the target using the acquired polariton image, as shown in the following formula: ; In the formula, I x for I 45 or I 135 Substituting both values ​​into the formula and taking the geometric mean of φ, we can use this to average the error. I 0、 I 90 , I 45 , I 135 The light intensity information of polariton images corresponding to 0°, 90°, 45°, and 135° respectively; S500: By analyzing and calculating the mapping relationship between the polarization characteristics of light waves and the three-dimensional morphological features of the surface of a spatial object, the azimuth angle of the target object is interpreted using the phase angle φ and the degree of polarization ρ. and zenith As shown in the following formula: ; In the formula, n is the refractive index of the reflecting medium. Since the azimuth angle is the angle between the projection of the surface normal onto the image plane and the coordinate axis, and the zenith angle is the angle between the observation direction and the normal direction, the target normal vector can be obtained by combining the azimuth angle and zenith angle parameters. The three-dimensional contour reconstruction method based on the normal vector gradient field is used to realize the high-precision restoration of the three-dimensional shape features of the spatial object, thereby obtaining the three-dimensional information of the target object.

[0015] As can be seen from the above technical solution, the advantages and positive effects of the small space-based polarizing superlens camera and imaging method of the present invention are as follows: (1) By mounting the polarizing superlens camera on the support rod of the spacecraft, it can be used as the main optical system for on-orbit self-testing service. That is, the polarizing superlens camera is separated from the spacecraft by a certain distance through the support rod, and then the polarizing superlens camera takes a self-shot of the spacecraft. The polarizing superlens camera has the advantages of small size, light weight and high three-dimensional reconstruction efficiency, making the spacecraft more flexible and convenient when performing load balancing. (2) Two sets of polarizing superlens components are set adjacent to each other perpendicular to the optical axis. They can form two sets of orthogonal polariton images on the image plane at one time. That is, the camera can acquire four polariton images of the target in one shot and perform three-dimensional reconstruction in real time. Compared with the traditional catadioptric optical system, the volume is reduced by more than three times under the same imaging quality. (3) The heat dissipation component enables the polarization superlens camera to be stored at low temperature in orbit and to work effectively. An external heat dissipation plate and a heat dissipation coating are used on the outside of the camera to avoid the influence of the high and low temperature environment in the orbit. A composite structure of multi-layer heat dissipation plates is used inside the camera to achieve effective heat conduction of the heat-generating components. (4) The threaded gasket is threaded with the lens chamber to adjust the position of the lens body in the optical axis direction, thereby achieving fine assembly and adjustment of the optical system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional schematic diagram of a small space-based polarizing superlens camera according to an embodiment of the present invention; Figure 2 This is a front view schematic diagram of a small space-based polarizing superlens camera according to an embodiment of the present invention; Figure 3 for Figure 2 Schematic diagram of AA section; Figure 4 This is an exploded view of the internal heat dissipation components and imaging system of a small space-based polarizing superlens camera according to an embodiment of the present invention; Figure 5 This is a flowchart of a small space-based polarizing superlens imaging method according to an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1. Camera housing; 2. Light-shielding assembly; 3. Polarizing superlens assembly; 4. Imaging system; 5. Heat dissipation assembly; 30. Lens chamber; 31. Threaded gasket; 32. Lens body; 50. CMOS heat sink; 51. Timing drive heat sink; 52. Power supply heat sink; 53. Inner board screws; 40. CMOS detector imaging board; 41. Timing drive circuit board; 42. Power supply board; 54. First external heat sink; 55. Second external heat sink. Detailed Implementation

[0019] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application. This application can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0020] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0021] like Figures 1 to 3 As shown, according to a first aspect of the present invention, a small space-based polarizing superlens camera is provided, including a light-shielding component 2, a polarizing superlens component 3, an imaging system 4, and a heat dissipation component 5 disposed on a camera housing 1. The polarizing superlens component 3 is arranged in two groups according to the optical path direction. The light-shielding component 2 is disposed in front of the polarizing superlens component 3 according to the optical path direction. The imaging system 4 is disposed behind the polarizing superlens component 3 according to the optical path direction. The heat dissipation component 5 is used to regulate the heat of the imaging system 4.

[0022] In use, the polarizing superlens camera is mounted on a spacecraft's support rod, serving as the main optical system for on-orbit self-monitoring services. This involves maintaining a certain distance between the polarizing superlens camera and the spacecraft via the support rod, and then taking a self-image of the spacecraft using the camera. The polarizing superlens camera boasts advantages such as small size, light weight, and high 3D reconstruction efficiency, making payload balancing more flexible and convenient for the spacecraft. Simultaneously, two sets of polarizing superlens components 3, arranged perpendicular to the optical axis and adjacent to each other, can simultaneously generate two sets of orthogonal polariton images on the image plane. This means the camera can acquire four polariton images of the target in a single shot, enabling real-time 3D reconstruction. Compared to traditional catadioptric optical systems, this reduces the size by more than three times while maintaining the same imaging quality. The heat dissipation component 5 enables low-temperature storage and effective operation of the polarizing superlens camera in orbit. An external heat sink and heat dissipation coating are used externally to avoid the influence of high and low temperature environments in orbit; a multi-layered composite structure of heat sinks is used internally to achieve effective heat conduction of heat-generating components. The light-shielding assembly 2 uses a light-shielding cover, which is fixed to the polarizing superlens assembly 3 via a flange. Incident light passes through the light-shielding cover into the camera interior, thus preventing direct sunlight from hitting the polarizing superlens assembly 3 and causing damage. Four supplementary LEDs are arranged on the front panel of the camera housing 1 (the side where the light-shielding assembly 2 is located). Their functions are twofold: first, to provide supplementary lighting for the target scene when the spacecraft is in a shadow area; and second, to control multiple sets of LED switches to collect target intensity information, providing prior information for azimuth angle deambiguation in the 3D reconstruction algorithm.

[0023] like Figure 3 As shown, in some embodiments of the present invention, the polarizing superlens assembly 3 includes a mirror chamber 30, a threaded washer 31, and a lens body 32. The mirror chamber 30 has an internal thread, and the threaded washer 31 is threadedly connected to the mirror chamber 30 via the internal thread. The lens body 32 is disposed on the threaded washer 31, and the position of the lens body 32 along the optical axis is adjusted by the threaded washer 31. By rotating the threaded washer 31, the relative position of the threaded washer 31 within the mirror chamber 30 can be changed, thereby changing the position of the lens body 32 along the optical axis and adjusting the focal length of the optical system. Furthermore, the internal thread within the mirror chamber 30 also serves as a stray light diaphragm.

[0024] In some embodiments of the present invention, the heat dissipation component 5 includes an internal heat dissipation component and an external heat dissipation component. The internal heat dissipation component is disposed inside the camera housing, and the external heat dissipation component is disposed outside the camera housing. The heat of the imaging system is conducted to the external environment through the internal heat dissipation component. The operating temperature of the camera in space significantly affects the camera's imaging quality and is a key factor determining the lifespan and reliability of the polarizing superlens camera. To ensure on-orbit imaging quality and positioning accuracy, the main components of the camera need to maintain a high level of temperature stability throughout its entire lifespan. During on-orbit operation, the main body temperature of the camera is affected by various factors, including external heat flows such as direct sunlight, Earth's albedo, and Earth's infrared heat flow, as well as the effects of intermittent operation of the camera's internal heat sources. The unevenness of these heat sources over time will lead to uneven temperature distribution and fluctuations in the camera, subsequently causing thermal deformation of the camera's structural materials, altering the camera's optical path and focal length, and ultimately affecting the camera's imaging quality. To ensure the camera's on-orbit temperature stability and performance, the internal and external heat dissipation components need to work together. The internal heat dissipation components are primarily designed for the efficient conduction and dispersion of heat generated by internal heat sources within the camera, transferring heat away from internal components and preventing heat buildup in certain areas. The external heat dissipation components, on the other hand, focus on mitigating the effects of external heat flow, ensuring the camera maintains a suitable operating temperature even in complex spatial thermal environments, thus guaranteeing stable on-orbit operation and excellent performance. A heating element and a thermistor can also be installed on the top of the camera. The thermistor monitors the camera housing temperature in real time, and when it falls below a certain threshold, the heating element heats the camera to maintain its temperature.

[0025] like Figure 4 As shown, in some embodiments of the present invention, the internal heat dissipation assembly includes a CMOS heat sink 50, a timing drive heat sink 51, a power supply heat sink 52, and inner plate screws 53; the imaging system 4 includes a CMOS detector imaging board 40, a timing drive circuit board 41, and a power supply board 42; the CMOS heat sink 50, CMOS detector imaging board 40, timing drive circuit board 41, timing drive heat sink 51, power supply board 42, and power supply heat sink 52 are stacked sequentially; and the CMOS heat sink 50 and the CMOS detector imaging board 40 are attached together, the timing drive heat sink 51 is attached to the timing drive circuit board 41, and the power supply heat sink 52 is attached to the power supply board 42; the CMOS heat sink 50, the timing drive heat sink 51, and the power supply heat sink 52 are fixedly connected to the inside of the camera housing 1 by the inner plate screws 53.

[0026] By stacking and bonding the components sequentially, the heat conduction path is effectively shortened, allowing heat generated by the internal heat source of the camera to be conducted away more quickly through the heat sinks. This prevents excessive heat accumulation in certain areas and reduces uneven temperature distribution caused by heat buildup. Thermally conductive silicone can be used on the bonding surfaces to further increase heat conduction efficiency. The CMOS heat sink 50, timing drive heat sink 51, and power supply heat sink 52 can also be connected to the camera housing 1 via their sides, further increasing heat conduction efficiency between them.

[0027] The heat sink is fixedly connected to the camera housing 1 by the inner plate screws 53, which enhances the stability of the overall structure and ensures that the components will not shift due to vibration or external factors during camera operation, thus guaranteeing the continuity and stability of heat dissipation. At the same time, this structural design saves as much internal space as possible while ensuring heat dissipation performance, making the overall camera structure more compact. This is beneficial for small space-based polarizing superlens cameras to achieve efficient operation and excellent imaging in a limited space.

[0028] In some embodiments of the present invention, the inner plate screw 53 includes a screw head and a screw cap. The screw head has a threaded inner hole that matches the thread of the screw head. Adjacent sets of inner plate screws 53 are connected by the screw head and screw cap to form an integral heat-conducting structure. The inner plate screws 53 can be made of copper. The interconnection of the inner plate screws 53 to form an integral heat-conducting structure makes the heat conduction between the heat sink and the camera housing 1 smoother, further improving the heat dissipation efficiency of the camera. At the same time, this special connection method of the inner plate screws 53 also enhances the stability of the structure and effectively prevents the connection from loosening due to vibration or temperature changes. In practical applications, this design can ensure that the camera maintains stable heat dissipation performance during long-term operation, thereby ensuring the imaging quality and operational stability of the camera.

[0029] like Figure 1 or Figure 2 As shown, in some embodiments of the present invention, the external heat dissipation assembly includes a first external heat dissipation plate 54 and a second external heat dissipation plate 55, which are mounted to both sides of the camera housing 1 by screws. Both the first external heat dissipation plate 54 and the second external heat dissipation plate 55 can be made of 7075 aluminum alloy, with a heat dissipation coating on the outer surface and an emissivity of 0.7. The 7075 aluminum alloy material does not impose excessive additional burden on the overall camera, and the heat dissipation coating can improve the radiative heat dissipation capacity of the heat dissipation plate to a certain extent. The shapes of the first external heat dissipation plate 54 and the second external heat dissipation plate 55 are customized according to the contours of both sides of the camera housing 1, fitting tightly to the camera housing 1, reducing contact thermal resistance during heat conduction, and allowing heat to be conducted more quickly from the camera housing 1 to the heat dissipation plate, further improving the camera's heat dissipation effect.

[0030] like Figure 4 As shown, in some embodiments of the present invention, the imaging system includes a CMOS detector imaging board 40, a timing drive circuit board 41, and a power supply board 42. The CMOS detector imaging board 40 includes two CMOS image sensors and is used to perform photoelectric conversion. The timing drive circuit board 41 is used to configure the CMOS image sensors, control the transmission of image acquisition commands, transmit image data, and perform external communication. The power supply board 42 includes power supply and interface chips and is used to perform power supply and level conversion functions. The CMOS detector imaging board 40 includes two GSENSE2020 image detectors and includes the necessary filter capacitors and bypass capacitors. The timing drive circuit board 41 uses a ZYNQ7020, which includes a 1000Mbps Ethernet MAC and two independent CAN bus controllers to meet the system's functional requirements. 32-bit / 400MHz LPDDR2 DDR is used, which has a small single-chip size and a bandwidth of up to 400M×32×2=25Gbps. A 256Mbit SPI FLASH is used to store system files and configuration parameters. The power supply includes the FPGA power supply and the detector power supply. Interface chips include an Ethernet transceiver and a CAN transceiver. The Ethernet transceiver used is the YT8511H, a 10 / 100 / 1000Mbps adaptive Ethernet PHY that meets system requirements. The CAN transceiver used is the TCAN337, a CAN bus transceiver with bus fault detection, powered by a single 3.3V supply, in a small SOT23-8 package, and with a bus speed of up to 1Mbps.

[0031] According to a second aspect of the present invention, a method for imaging a small space-based polarizing superlens is provided, comprising the following steps: S100: Wiener filtering and Gaussian filtering are used to enhance the images acquired by the small space-based polarizing superlens camera; S200: The two acquired images are segmented based on the focal position to obtain four independent polariton images at 0°, 90°, 45°, and 135°. S300: Employs an image alignment method based on Fast Fourier Transform to achieve spatial registration of images of each polarizer; S400: Calculate the phase angle φ and polarization degree ρ of the diffuse reflected light from the target using the acquired polariton image, as shown in the following formula: ; In the formula, I x for I 45 or I135 Substituting both values ​​into the formula and taking the geometric mean of φ, we can use this to average the error. I 0、 I 90 , I 45 , I 135 The light intensity information of polariton images corresponding to 0°, 90°, 45°, and 135° respectively; S500: By analyzing and calculating the mapping relationship between the polarization characteristics of light waves and the three-dimensional morphological features of the surface of a space object, the azimuth angle of the target object is interpreted using the calculated phase angle φ and polarization degree ρ. and zenith As shown in the following formula: ; In the formula, n is the refractive index of the reflecting medium. Since the azimuth angle is the angle between the projection of the surface normal onto the image plane and the coordinate axis, and the zenith angle is the angle between the observation direction and the normal direction, the target normal vector can be obtained by combining the azimuth angle and zenith angle parameters. The three-dimensional contour reconstruction method based on the normal vector gradient field is used to realize the high-precision restoration of the three-dimensional shape features of the spatial object, thereby obtaining the three-dimensional information of the target object.

[0032] In some embodiments of this invention, polarization imaging is mainly achieved by capturing multiple (usually 3 or 4) intensity images modulated by different analyzers, followed by polarization information extraction. Therefore, simultaneous detection of multiple images and real-time extraction of polarization information are prerequisites for the practical application of polarization imaging technology. Based on different methods of acquiring polarization images, current polarization imaging devices mainly fall into two categories: time-division polarization imaging devices and simultaneous polarization imaging devices. Time-division polarization imaging devices have a relatively simple structure and are suitable for polarization imaging of stationary targets, primarily used for verifying the principles of polarization imaging. Simultaneous polarization imaging devices have a relatively complex structure and can perform polarization imaging of moving targets, exhibiting greater adaptability.

[0033] The camera is based on polarizing superlens imaging. It collects diffusely reflected light scattered from the target surface and obtains images of different polarization sub-images through the superlens. Using a polarizing superlens instead of the traditional combination of optical lens groups and polarizers reduces the camera's mass and size, simplifying assembly and maintenance. The system utilizes the diffuse reflected light from the target for 3D imaging, specifically leveraging the weak polarization characteristics of the diffuse component in the reflected light from the object's surface to measure its 3D shape. Using a polarization-sensitive superlens for imaging, the 3D information of the target object is calculated from the obtained three polarization sub-images.

[0034] The incident light passes through a single orthogonal polarizing superlens and forms two spatially separated orthogonal polarization images at the image plane, which are 45°, 135°, 0°, and 90° respectively.I 0、 I 90 , I 45 , I 135 The system receives four light intensity images corresponding to the CMOS photosensitive surface. A CMOS photosensitive surface is placed at the image plane of the optical system to simultaneously receive images at multiple different polarization angles. The 0°, 45°, 90°, and 135° polarization sub-images generated by the system are transmitted to the host computer as input for the polarization 3D reconstruction module.

[0035] The phase angle φ and polarization degree ρ of the diffuse reflected light from the target are calculated using the collected light intensity information; ; The azimuth angle of the target object is interpreted using the phase angle φ and the degree of polarization ρ. and zenith : ; In the formula, n is the refractive index of the reflecting medium. Since the azimuth angle is the angle between the projection of the surface normal onto the image plane and the coordinate axis, and the zenith angle is the angle between the observation direction and the normal direction, the target normal vector can be obtained by combining the two parameters, thereby enabling the three-dimensional reconstruction of the target.

[0036] However, as shown in the above equation, the azimuth angle of the target surface is ambiguous, which leads to distortion in the 3D reconstructed shape recovered by the surface normal integral. Accurate interpretation of the azimuth angle information is therefore crucial. Simply using polarization information for 3D reconstruction results in ambiguity and makes it difficult to obtain ideal results. Combining multi-angle illuminated target images as prior information can resolve this ambiguity issue.

[0037] The above system was used to study the multi-angle polarization characteristic testing method of the basic material of typical space targets, obtain polarization characteristic measurement data, form a polarization characteristic dataset of the basic material of typical space targets, and at the same time construct a theoretical model of polarization reflection characteristics, and summarize the polarization characteristics of space targets and their reflection radiation polarization distribution characteristics and variation laws in typical bands.

[0038] Using a satellite model as the target, incident light passes through the solar panel, and scattered light passes through a polarizing superlens to reach the photosensitive surface of the detector. The light then passes through an electronic processing unit to a computer for storage and processing. The object distance is adjusted to produce a clear image on the detector's focal plane, resulting in polariton images at 0°, 90°, 45°, and 135°, which are then saved.

[0039] Use the following formula to calculate image contrast: ; Where Imax and Imin are the maximum and minimum light intensities in the image, respectively, the contrast is calculated. It can be seen that the image obtained using an orthogonally linearly polarized superlens has lower contrast, which is mainly due to the current limitations in superlens manufacturing capabilities.

[0040] The imaging effect of an optical system is affected by factors such as optical system aberrations, mechanical structure tolerances, detector sampling, and temperature changes. After image acquisition, Wiener filtering and Gaussian filtering are used for image enhancement. Based on the bifocal position, each image is segmented into two independent images, thus obtaining four segmented polariton images at 0°, 90°, 45°, and 135°. An image alignment method based on Fast Fourier Transform is used to achieve spatial registration of each polariton image. By analyzing and calculating the mapping relationship between the polarization characteristics of light waves and the three-dimensional morphological features of the surface of a spatial object, a three-dimensional contour reconstruction method based on the normal vector gradient field is used to achieve high-precision restoration of the three-dimensional morphological features of the spatial object, thereby obtaining the three-dimensional information of the target object.

[0041] The embodiments of this application have now been described in detail. To avoid obscuring the concept of this application, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0042] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any manner.

Claims

1. A small space-based polarizing superlens camera, characterized in that, The device includes a light-shielding assembly, a polarizing superlens assembly, an imaging system, and a heat dissipation assembly, all mounted on the camera housing. The polarizing superlens assembly is arranged in two sets according to the optical path direction. The light-shielding assembly is positioned in front of the polarizing superlens assembly according to the optical path direction, and the imaging system is positioned behind the polarizing superlens assembly according to the optical path direction. The heat dissipation assembly is used to regulate the heat of the imaging system.

2. The miniature space-based polarizing superlens camera according to claim 1, characterized in that, The polarizing superlens assembly includes a mirror chamber, a threaded gasket, and a lens body. The mirror chamber is provided with an internal thread, and the threaded gasket is connected to the mirror chamber by the internal thread. The lens body is disposed on the threaded gasket, and the position of the lens body in the optical axis direction is adjusted by the threaded gasket.

3. The miniature space-based polarizing superlens camera according to claim 1, characterized in that, The heat dissipation assembly includes an internal heat dissipation assembly and an external heat dissipation assembly. The internal heat dissipation assembly is disposed inside the camera housing, and the external heat dissipation assembly is disposed outside the camera housing. The heat of the imaging system is conducted to the external environment through the internal heat dissipation assembly and the external heat dissipation assembly.

4. The miniature space-based polarizing superlens camera according to claim 3, characterized in that, The internal heat dissipation components include a CMOS heat sink, a timing drive heat sink, a power supply heat sink, and inner plate screws; the imaging system includes a CMOS detector imaging board, a timing drive circuit board, and a power supply board; the CMOS heat sink, CMOS detector imaging board, timing drive circuit board, timing drive heat sink, power supply board, and power supply heat sink are stacked sequentially; the CMOS heat sink and the CMOS detector imaging board are attached together, the timing drive heat sink is attached to the timing drive circuit board, and the power supply heat sink is attached to the power supply board; the CMOS heat sink, timing drive heat sink, and power supply heat sink are fixedly connected to the inside of the camera housing by the inner plate screws.

5. The miniature space-based polarizing superlens camera according to claim 4, characterized in that, The inner plate screw includes a screw head and a screw cap. The screw head has a threaded inner hole that matches the thread of the screw head. Two adjacent sets of inner plate screws are connected by the screw head and screw cap to form an integral heat-conducting structure.

6. The miniature space-based polarizing superlens camera according to claim 5, characterized in that, The external heat dissipation assembly includes a first external heat dissipation plate and a second external heat dissipation plate, which are mounted on both sides of the camera housing by screws.

7. The miniature space-based polarizing superlens camera according to claim 4, characterized in that, The CMOS detector imaging board contains two CMOS image sensors and is used to perform photoelectric conversion.

8. The miniature space-based polarizing superlens camera according to claim 7, characterized in that, The timing driver circuit board is used to configure the CMOS image sensor, control the sending of image acquisition commands, transmit image data, and perform external communication functions.

9. The miniature space-based polarizing superlens camera according to claim 7, characterized in that, The power board includes a power supply and an interface chip, and is used to perform power supply and level conversion functions.

10. A method for imaging with a small-scale space-based polarizing superlens, characterized in that, Based on the miniature space-based polarizing superlens camera according to any one of claims 1 to 9, the method includes the following steps: S100: Wiener filtering and Gaussian filtering are used to enhance the images acquired by the small space-based polarizing superlens camera; S200: The two acquired images are segmented based on the focal position to obtain four independent polariton images at 0°, 90°, 45°, and 135°. S300: Employs an image alignment method based on Fast Fourier Transform to achieve spatial registration of images of each polarizer; S400: Calculate the phase angle φ and polarization degree ρ of the diffuse reflected light from the target using the acquired polariton image, as shown in the following formula: ； In the formula, I x for I 45 or I 135 Substituting both values ​​into the formula and taking the geometric mean of φ, we can use this to average the error. I 0、 I 90 , I 45 , I 135 The light intensity information of polariton images corresponding to 0°, 90°, 45°, and 135° respectively; S500: By analyzing and calculating the mapping relationship between the polarization characteristics of light waves and the three-dimensional morphological features of the surface of a spatial object, the azimuth angle of the target object is interpreted using the phase angle φ and the degree of polarization ρ. and zenith As shown in the following formula: ； In the formula, n is the refractive index of the reflecting medium. Since the azimuth angle is the angle between the projection of the surface normal onto the image plane and the coordinate axis, and the zenith angle is the angle between the observation direction and the normal direction, the target normal vector can be obtained by combining the azimuth angle and zenith angle parameters. The three-dimensional contour reconstruction method based on the normal vector gradient field is used to realize the high-precision restoration of the three-dimensional shape features of the spatial object, thereby obtaining the three-dimensional information of the target object.

Images