Space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding

Abstract

This invention relates to a space-based infrared staring imaging system based on detector multiplexing and field-of-view modulation coding, and relates to the technical fields of modulation coding, detector multiplexing, and space-based infrared staring imaging systems. The system includes, arranged sequentially along the light incident direction: a front mirror group, a field-of-view modulation coding element, a rear mirror group, and a detector multiplexing assembly. The space-based infrared staring imaging system based on detector multiplexing and field-of-view modulation coding of this invention achieves an integrated design of detector multiplexing and field-of-view modulation, solving the problems of large weight, large size, high cost, and high requirements for detector manufacturing processes in traditional space-based infrared early warning systems. It provides a lightweight architecture for achieving large field-of-view real-time staring imaging with a single space payload.

Description

Technical Field

[0001] This invention relates to the fields of modulation coding, detector multiplexing, and space-based infrared staring imaging systems, and particularly to a space-based infrared staring imaging system based on detector multiplexing and field-of-view modulation coding. Background Technology

[0002] Space-based infrared staring imaging systems are a key application area of ​​space optical detection, widely used for on-orbit monitoring of high-temperature radiation targets on the Earth's surface and in near-Earth space, especially infrared point sources with high-speed motion characteristics, such as spacecraft exhaust plumes, space debris combustion, or other transient thermal events. In recent years, with continuous advancements in satellite platforms, launch vehicles, and infrared detector manufacturing processes, constructing space-based infrared observation systems with both high resolution and wide coverage has become possible. However, limitations in the array size, pixel scale, and detection sensitivity of current detectors still present bottlenecks in expanding the field of view (FOV). Limited detector arrays often cannot simultaneously achieve high-resolution imaging and wide-area coverage, making it difficult for a single satellite to continuously stare over large areas, especially hindering stable acquisition and continuous tracking of fast-moving targets. Therefore, how to achieve large field of view, high-resolution imaging, and dynamic target recognition under limited detector conditions has become a pressing technical challenge in the field of space-based infrared observation.

[0003] To overcome the contradiction between detector scale and field of view, existing research has proposed various solutions. For example, pushbroom imaging relies on satellite orbital motion to achieve wide-area coverage, but this method places extremely high demands on platform attitude stability and on-orbit data processing capabilities, and targets are prone to missed detection due to insufficient time sampling during the imaging cycle. While multi-satellite networking can alleviate the inadequacy of single-satellite coverage to some extent, the implementation costs of its constellation scale, on-orbit formation control, and high-speed data transmission links are all very high. The development of large-area high-sensitivity detectors can directly extend the system's field of view, but it is currently difficult to meet the needs of engineering applications due to manufacturing difficulties and costs. In addition, some methods attempt to achieve wide-area monitoring through optical structure optimization or multi-focal plane detection, but in complex target scenarios, it is often difficult to balance resolution, sensitivity, and real-time performance. Although these solutions have their own achievements, they generally suffer from high implementation complexity, poor engineering adaptability, or excessive costs, and are not yet sufficient to support large-scale applications, nor can they fundamentally overcome the bottlenecks in detector manufacturing processes. Summary of the Invention

[0004] This invention aims to address the technical problems of existing space-based infrared early warning systems, such as large weight and volume, high cost and manufacturing requirements, and the inability to simultaneously consider resolution, sensitivity and real-time performance when choosing between detector size and field of view. It provides a space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] A space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding includes, in sequence along the light incident direction: a front mirror group, a field-of-view modulation coding element, a rear mirror group, and a detector multiplexing component;

[0007] The front lens group is used to handle the system's optical power and form the intermediate image plane;

[0008] The field-of-view modulation and coding element is located at the central image plane to enable the system to modulate and code different field-of-view zones.

[0009] The rear lens group is used to achieve focused imaging after transmission;

[0010] The detector multiplexing component is used to fold the optical path and then receive a large field-of-view imaging image with a small array detector.

[0011] In the above technical solution, the detector multiplexing component is composed of four planar reflectors spliced ​​together in a tetrahedral shape, which is used to converge large field-of-view imaging light onto the same surface array detector by refraction of the light path.

[0012] In the above technical solution, the field-of-view modulation coding element is a cylindrical mirror with curvature in the Y direction.

[0013] In the above technical solution, the field-of-view modulation coding element is a phase plate.

[0014] In the above technical solution, the optical path structure composed of the front mirror group, the field-of-view modulation coding element and the rear mirror group is a refractive structure.

[0015] In the above technical solution, the materials of the lenses in the front lens group, the field-of-view modulation coding element, and the rear lens group are: SILICA, GERMANIUM, or ZNS.

[0016] In the above technical solution, the front lens group includes, in sequence along the light incident direction: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; the first lens is a positive meniscus lens, the second lens is a negative meniscus lens, the third lens is a positive meniscus lens, the fourth lens is a negative meniscus lens, and the fifth lens is a biconvex lens; the field-of-view modulation coding element is a sixth lens;

[0017] The air gap between the first and second lenses is 17.623 mm, the air gap between the second and third lenses is 21.186 mm, the air gap between the third and fourth lenses is 33.807 mm, the air gap between the fourth and fifth lenses is 25.872 mm, and the air gap between the fifth and sixth lenses is 38.999 mm.

[0018] In the above technical solution, the rear mirror group includes, in sequence along the light incident direction, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens; the seventh lens is a negative meniscus lens, the eighth lens is a negative meniscus lens, the ninth lens is a positive meniscus lens, the tenth lens is a positive meniscus lens, the eleventh lens is a negative meniscus lens, the twelfth lens is a positive meniscus lens, and the thirteenth lens is a positive meniscus lens; the field-of-view modulation coding element is the sixth lens; and the detector multiplexing assembly is the fourteenth lens.

[0019] The air gap between the sixth and seventh lenses is 50.744 mm, the air gap between the seventh and eighth lenses is 20.644 mm, the air gap between the eighth and ninth lenses is 21.178 mm, the air gap between the ninth and tenth lenses is 99.725 mm, the air gap between the tenth and eleventh lenses is 20.722 mm, the air gap between the eleventh and twelfth lenses is 31.290 mm, the air gap between the twelfth and thirteenth lenses is 45.512 mm, and the air gap between the thirteenth and fourteenth lenses is 7 mm.

[0020] The present invention has the following beneficial effects:

[0021] The space-based infrared staring imaging system based on detector multiplexing and field-of-view modulation coding of this invention realizes the integrated design of detector multiplexing and field-of-view modulation, solving the problems of large weight, large size, high cost, and high requirements for detector manufacturing process in traditional space-based infrared early warning systems. It provides a lightweight architecture for achieving large field-of-view real-time staring imaging with a single space payload. Specifically:

[0022] Small array achieves large field of view, lightweight structure and strong real-time performance: Through optical path folding design, multiple field of view rays are converged to the imaging surface of a single small array detector, realizing low power consumption and low cost of large field of view imaging. At the same time, it avoids the problems of large size, heavy weight and insufficient real-time performance caused by traditional solutions such as oscillating scanning imaging and detector stitching. It is particularly suitable for continuous monitoring of fast-moving infrared targets.

[0023] Field of view partitioning modulation and marking: By introducing partitioning modulation elements (such as cylindrical mirrors, phase plates, etc.), distinguishable geometric or phase modulation is introduced into the light rays in different field of view regions, so that the imaging light spot has field of view-dependent morphological characteristics, which makes it easier for subsequent algorithms to quickly distinguish the target sources in different fields of view and improve the target localization capability under multi-field of view fusion.

[0024] High compatibility and scalability: The optical design of the imaging system of this invention can be combined with a variety of back-end image processing algorithms and signal recognition methods to adapt to different task requirements and can be extended to multispectral or other imaging application scenarios. Attached Figure Description

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 This is a schematic diagram illustrating the working principle of the space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding according to the present invention.

[0027] Figure 2 This is a schematic diagram of the optical path structure of the space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding according to the present invention.

[0028] Figure 3 This is a schematic diagram of the MTF curve of the space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding according to the present invention.

[0029] Figure 4 This is a point array schematic diagram of the space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding according to the present invention.

[0030] Figure 5 This is a schematic diagram of the point array of the space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding of the present invention after field-of-view modulation coding.

[0031] Figure 3-5 In this context, Zemax is an optical design and simulation software suite from Ansys, Inc. in the United States. ZemaxOpticStudio 19.4 is the core module of Zemax, supporting the design of imaging, illumination and laser systems. It is used in aerospace engineering, astronomical exploration, biomedical research and consumer electronics, providing optical modeling, performance optimization and tolerance analysis functions.

[0032] The reference numerals in the figure are:

[0033] 1-First lens; 2-Second lens; 3-Third lens; 4-Fourth lens; 5-Fifth lens;

[0034] 6 - Sixth lens; 7 - Seventh lens; 8 - Eighth lens; 9 - Ninth lens; 10 - Tenth lens;

[0035] 11 - Eleventh lens; 12 - Twelfth lens; 13 - Thirteenth lens; 14 - Fourteenth lens. Detailed Implementation

[0036] The inventive concept of this invention is as follows:

[0037] The space-based infrared staring imaging system based on detector multiplexing and field-of-view modulation coding of the present invention proposes the idea of ​​infrared detector multiplexing imaging under a large field of view, under the premise of applying the aliased image target recognition and localization algorithm based on field-of-view modulation coding. The method of detector multiplexing-field-of-view modulation coding is adopted so that the light originally imaged on the large array detector is folded and imaged on the small array detector after modulation coding. Based on this, the space-based infrared staring imaging system under detector multiplexing is designed. It realizes the advantages of low power consumption and low cost of small target detector to achieve wide swath detection of space-based infrared, and breaks through the bottleneck of infrared optical system large field of view imaging limited by infrared detector manufacturing process.

[0038] The space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding of the present invention introduces a coding modulation module at the optical front end, which folds and compresses the multi-field light rays that originally needed to cover a large-area array focal plane onto a single small-area array detector, thereby significantly reducing the detector size and manufacturing difficulty.

[0039] The present invention will now be described in detail with reference to the accompanying drawings.

[0040] The space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding of the present invention, such as Figure 1 and 2 As shown, along the direction of light incidence, the following components are arranged sequentially: a front mirror group, a field-of-view modulation and coding element, a rear mirror group, and a detector multiplexing assembly. The optical path structure formed by the front mirror group, the field-of-view modulation and coding element, and the rear mirror group is a refractive structure, composed of 13 lenses (6 spherical lenses, 6 aspherical lenses, and 1 cylindrical lens), using lens materials including SILICA, GERMANIUM, or ZNS. The detector multiplexing assembly is composed of four planar mirrors, forming a tetrahedral shape. Through the refraction of the light path, it converges the large field-of-view imaging light rays onto a single small array detector.

[0041] The specific optical path operation mode of the space-based infrared staring imaging system based on detector multiplexing and field-of-view modulation coding of the present invention is as follows: a coaxial refracting optical system is used for full-aperture imaging. Specifically, the front mirror group is used to handle the system's optical power and form the intermediate image plane; the field-of-view modulation coding element is located at the intermediate image plane to realize the modulation coding of different field-of-view partitions; the rear mirror group is used to achieve focused imaging after transmission; and the detector multiplexing assembly is used to refract the optical path and receive the large field-of-view imaging image with a small array detector.

[0042] like Figure 2As shown, the space-based infrared staring imaging system based on detector multiplexing and field-of-view modulation coding of the present invention uses a detector multiplexing component to receive a large field-of-view image with a small-area array detector, and then uses a field-of-view modulation coding element to perform partitioned modulation coding on targets in different field-of-view regions on the aliased image. This achieves space-based infrared wide-swath detection by leveraging the advantages of low power consumption and low cost of the small-area detector. The system focal length of the present invention is -121.218mm, the total lens length is 575.104mm, the spectral range is 3μm-5μm, the system aperture is 60.7mm, and the field of view is φ30 degrees. The imaging quality has a full-field-of-view wavelet aberration better than 1 / 15λ, and the F-number is 2. The specific parameters of the selected small-area array detector are: 1024×1024 pixels, and a pixel size of 15μm.

[0043] In the space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding of the present invention:

[0044] The front lens group includes, in sequence along the direction of light incidence: first lens 1, second lens 2, third lens 3, fourth lens 4 and fifth lens 5; first lens 1 is a positive meniscus lens, second lens 2 is a negative meniscus lens, third lens 3 is a positive meniscus lens, fourth lens 4 is a negative meniscus lens, and fifth lens 5 is a biconvex lens;

[0045] The field-of-view modulation coding element is the sixth lens 6. In this embodiment, the sixth lens 6 is a cylindrical mirror with curvature in the Y direction. The Y direction refers to the vertical direction of the incident light, i.e., the meridional direction. Correspondingly, the X direction is the horizontal direction of the incident light, i.e., the sagittal direction. In other specific embodiments, the sixth lens 6 can also be a phase plate.

[0046] The rear lens group, along the direction of light incidence, includes, in sequence: seventh lens 7, eighth lens 8, ninth lens 9, tenth lens 10, eleventh lens 11, twelfth lens 12, and thirteenth lens 13; seventh lens 7 is a negative meniscus lens, eighth lens 8 is a negative meniscus lens, ninth lens 9 is a positive meniscus lens, tenth lens 10 is a positive meniscus lens, eleventh lens 11 is a negative meniscus lens, twelfth lens 12 is a positive meniscus lens, and thirteenth lens 13 is a positive meniscus lens;

[0047] The detector multiplexing component is the fourteenth lens 14, which is composed of four plane mirrors spliced ​​together.

[0048] The air gap between the first lens 1 and the second lens 2 is 17.623 mm; the air gap between the second lens 2 and the third lens 3 is 21.186 mm; the air gap between the third lens 3 and the fourth lens 4 is 33.807 mm; the air gap between the fourth lens 4 and the fifth lens 5 is 25.872 mm; the air gap between the fifth lens 5 and the sixth lens 6 is 38.999 mm; the air gap between the sixth lens 6 and the seventh lens 7 is 50.744 mm; and the air gap between the seventh lens 7 and the eighth lens 8 is... The air gap between the eighth lens 8 and the ninth lens 9 is 21.178 mm, the air gap between the ninth lens 9 and the tenth lens 10 is 99.725 mm, the air gap between the tenth lens 10 and the eleventh lens 11 is 20.722 mm, the air gap between the eleventh lens 11 and the twelfth lens 12 is 31.290 mm, the air gap between the twelfth lens 12 and the thirteenth lens 13 is 45.512 mm, and the air gap between the thirteenth lens 13 and the fourteenth lens 14 is 7 mm.

[0049] Lens 1 is made of SILICON glass, Lens 2 is made of GERMANIUM glass, Lens 3 is made of GERMANIUM glass, Lens 4 is made of GERMANIUM glass, Lens 5 is made of SILICON glass, Lens 6 is made of SILICON glass, Lens 7 is made of GERMANIUM glass, Lens 8 is made of ZNS_BROAD glass, Lens 9 is made of SILICON glass, Lens 10 is made of SILICON glass, Lens 11 is made of GERMANIUM glass, Lens 12 is made of SILICON glass, and Lens 13 is made of GERMANIUM glass.

[0050] In the space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding of the present invention, each lens of the optical system satisfies the following condition:

[0051] (1) The optical characteristics of the first lens 1 are:

[0052] -0.8f<f1<-0.3f, 3<n1<4, 0.7f1<R1<1.3f1, 1.2f1<R2<1.8f1, D1=10.782, D2=9.392;

[0053] (2) The optical characteristics of the second lens 2 are:

[0054] 0.2f<f2<0.6f, 3.5<n2<4.5, -1.6f2<R3<-1.2f2, -f2<R4<-0.7f2, D3=8.231, D4=13.839, 0.2<κ1<0.3;

[0055] (3) The optical characteristics of the third lens 3 are:

[0056] -1.7f<f3<-1.3f, 3.5<n3<4.5, 0.9f3<R5<1.3f3, 1.5f3<R6<1.8f3, D5=7.347, D6=26.753;

[0057] (4) The optical characteristics of the fourth lens 4 are:

[0058] 0.9f<f4<1.1f, 3.5<n4<4.5, 1.5f4<R7<1.9f4, 4.1f4<R8<4.4f4, D7=7.055, D8=18.682, 7<κ2<8;

[0059] (5) The optical characteristics of the fifth lens 5 are:

[0060] -0.7f<f5<-0.3f, 3<n5<4, 2.5f5<R9<2.8f5, -30f5<R 10 <-27f5, D9 = 7.190, D 10 =34.399;

[0061] (6) The optical characteristics of the sixth lens 6 are:

[0062] f< <f6,3<n6<4,R 11 ≈+∞,R 12 ≈-1500, D 11 =4.600, D 12 =36.596;

[0063] (7) The optical characteristics of the seventh lens 7 are:

[0064] 1.7f<-229.814f7<2.1f, 3.5<n7<4.5, 0.2f7<R 13 <0.6f7, 0.7f7 <R 14 <1.1f7, D 13 =14.148, D 14 =6.430, -5 < κ3 < -4;

[0065] (8) The optical characteristics of the eighth lens 8 are:

[0066] 2.5f<f8<2.9f, 1.3<n8<3, 0.5f8<R15 <0.7f8, f8<R 16 <1.4f8, D 15 =14.214, D 16 =5.177, 5.5 < κ4 < 6.1;

[0067] (9) The optical characteristics of the ninth lens 9 are:

[0068] -f<f9<-0.3f, 3<n9<4, -4f9<R 17 <-3f9, -2f9<R 18 <-f9,D 17 =16.001, D 18 =83.803;

[0069] (10) The optical characteristics of the tenth lens 10 are:

[0070] -0.9f<f 10 <-0.3f, 3<n 10 <4, f 10 <R 19 <2f 10 , 4f 10 <R 20 <4.8f 10 D 19 =15.921, D 20 =5.002;

[0071] (11) The optical characteristics of the eleventh lens 11 are:

[0072] 0.2f < f 11 <0.7f, 3.5<n 11 <4.5, -9.1f 11 <R 21 <-8.3f 11 -2.5f 11 <R 22 <-1.9f 11 D 21 =15.720, D 22 =15.332;

[0073] (12) The optical characteristics of the twelfth lens 12 are:

[0074] -0.8f<f 12 <-0.3f, 3<n 12 <4, 1.2f 12 <R 23 <1.7f 12 ,3f 12 <R 24 <-3.3f12 D 23 =15.959, D 24 =29.514;

[0075] (13) The optical characteristics of the thirteenth lens 13 are:

[0076] -33f < 3792.076f 13 <-30f, 3.5<n 13 <4.5, 0.01f13<R 25 <0.02f13, 0.009f 13 <R 26 <0.017f 13 D 25 =15.998, D 26 =7.000, 0.1<κ5<0.14, 0.17<κ6<0.22;

[0077] Where f is the overall focal length of the optical system; f1, f2, f3...f 13 These are the first lens 1, the second lens 2, the third lens 3, ..., the thirteenth lens 13, and their focal lengths: R1, R2, R3...R 26 These are the radii of curvature of the twenty-six surfaces of the thirteen lenses arranged sequentially along the direction of light incidence; n1, n2, n3...n 13 These are the refractive indices of the thirteen lenses arranged sequentially along the direction of light incidence; D1, D2...D... 26 These are the thicknesses of the twenty-six surfaces of the thirteen lenses arranged sequentially along the incident direction of light. The lenses in this configuration include: second lens 2, fourth lens 4, seventh lens 7, eighth lens 8, and thirteenth lens 13, all of which are aspherical lenses, while the rest are spherical lenses; κ1, κ2, κ3, κ4, κ5, and κ6 are the aspherical conic coefficients of the second surface of second lens 2, the second surface of fourth lens 4, the second surface of seventh lens 7, the first surface of eighth lens 8, the first surface of thirteenth lens 13, and the second surface of thirteenth lens 13, arranged sequentially along the incident direction of light.

[0078] The space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding of the present invention implements field-of-view modulation coding in the following principle:

[0079] When a cylindrical mirror with curvature in the Y direction is used as a field-of-view modulation and coding element to shape incident light in a large field of view, it introduces various off-axis aberrations. These off-axis aberrations not only evolve with the field of view position, but their directional differences and amplitude variations also directly determine the adjustable characteristics of the light spot. Specifically, under the action of the sixth lens 6 of the cylindrical mirror, which acts as a field-of-view modulation and coding element: when the field of view expands along the X direction, the coma direction and the principal axis of astigmatism rotate, causing the focal line of the light spot to deflect accordingly; while when the field of view increases along the Y direction, astigmatism and field curvature effects are enhanced, causing the size of the light spot to stretch or shrink in a specific direction. The combined effect significantly changes the geometric characteristics of the light spot, resulting in controllable and differentiated geometric features of the light spot under different fields of view. Based on this principle, this invention utilizes a cylindrical mirror to modulate and shape the light spot to achieve the marking and differentiation of targets in different fields of view.

[0080] Imaging quality of the space-based infrared staring imaging system based on detector multiplexing field-of-view modulation coding of the present invention:

[0081] In the imaging optical path of this invention, the selected small-area detector pixel size is 15μm. For example... Figure 3 As shown, within the 3μm-5μm operating band, the modulation transfer function (MTF) of this imaging optical path remains above 0.30 at the Nyquist frequency of approximately 33.3 lp / mm for a detector pixel size of 15μm, indicating that the present invention still possesses ideal imaging contrast at the cutoff frequency. These results demonstrate that the system aberrations of the present invention are adequately controlled, and edge details, texture information, and contour features are clearly transmitted. This significantly improves target recognition, localization capabilities, and the accuracy of centroid extraction, meeting the requirements for achieving wide-swath space-based infrared detection with the advantages of low power consumption and low cost of a small-target detector.

[0082] like Figure 4 and 5 As shown, the geometric changes in the light spot caused by off-axis aberrations not only possess stable directionality but also exhibit consistent controllability within the two-dimensional field of view. This establishes a physically reasonable and repeatable mapping relationship between aberration-modulated light spot features and the target's field of view position. The encoding mechanism relies on the monotonic and stable trends of the changes in the light spot shape features driven by these aberrations. It is these stable trends that provide sufficient discriminative information to distinguish different sub-field of view regions. This method not only fully utilizes the physical response characteristics of the imaging system but also provides more discriminative feature support for the localization of small targets in complex backgrounds.

[0083] The feasibility of this invention has been verified through theoretical analysis, optical modeling, and numerical simulation. Simulation results show that, under the same detector specifications, this scheme can effectively expand the system's field of view, enabling imaging of multiple field-of-view rays on a single detector array, while maintaining high imaging resolution and spot discrimination. Some functional principles have been preliminarily verified through an experimental platform, and the experimental results are consistent with the simulation predictions, indicating that this scheme has good engineering feasibility and application potential.

[0084] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A space-based infrared staring imaging system based on detector multiplexing sub-field modulation coding, characterized in that, The front lens group, the sub-field modulation coding element, the rear lens group and the detector multiplexing assembly are sequentially arranged along the light incident direction. The front lens group is used to bear the system focal power and form an intermediate image plane. The sub-field modulation coding element is arranged at the intermediate image plane and is used to realize modulation coding of different field partitions of the system. The rear lens group is used to transmit and focus the image. The detector multiplexing assembly is used to fold the light path and receive the large field imaging image by a facet array detector. The front lens group sequentially comprises a first lens (1), a second lens (2), a third lens (3), a fourth lens (4) and a fifth lens (5) along the light incident direction; the first lens (1) is a positive meniscus lens, the second lens (2) is a negative meniscus lens, the third lens (3) is a positive meniscus lens, the fourth lens (4) is a negative meniscus lens, and the fifth lens (5) is a double convex lens; and the sub-field modulation coding element is a sixth lens (6). The air gap between the first lens (1) and the second lens (2) is 17.623 mm, the air gap between the second lens (2) and the third lens (3) is 21.186 mm, the air gap between the third lens (3) and the fourth lens (4) is 33.807 mm, the air gap between the fourth lens (4) and the fifth lens (5) is 25.872 mm, and the air gap between the fifth lens (5) and the sixth lens (6) is 38.999 mm.

2. The space-based infrared staring imaging system based on detector multiplexing sub-field modulation coding according to claim 1, characterized in that, The detector multiplexing assembly is composed of four plane mirrors and has a tetrahedron shape, and is used to converge the large field imaging light on the same facet array detector by folding the light path.

3. The space-based infrared staring imaging system based on detector multiplexing sub-field modulation coding according to claim 1, characterized in that, The sub-field modulation coding element is a cylindrical lens with Y direction curvature, and the Y direction is the vertical direction of the incident light, i.e. the meridional plane direction.

4. The detector multiplexing sub-field modulation coding based space-borne infrared staring imaging system according to claim 1, wherein, The sub-field modulation coding element is a phase plate.

5. The detector multiplexing subfield modulation coding based space-borne infrared staring imaging system according to claim 1, wherein, The optical path structure composed of the front lens group, the sub-field modulation coding element and the rear lens group is a refractive structure.

6. The detector multiplexing subfield modulation coding based space-based infrared staring imaging system according to claim 1, wherein, The materials of the lenses in the front lens group, the sub-field modulation coding element and the rear lens group are silicon dioxide, germanium or zinc sulfide.

7. The detector multiplexing subfield modulation coding based space-borne infrared staring imaging system according to claim 1, wherein, The rear lens group sequentially comprises a seventh lens (7), an eighth lens (8), a ninth lens (9), a tenth lens (10), an eleventh lens (11), a twelfth lens (12) and a thirteenth lens (13) along the light incident direction; the seventh lens (7) is a negative meniscus lens, the eighth lens (8) is a negative meniscus lens, the ninth lens (9) is a positive meniscus lens, the tenth lens (10) is a positive meniscus lens, the eleventh lens (11) is a negative meniscus lens, the twelfth lens (12) is a positive meniscus lens, and the thirteenth lens (13) is a positive meniscus lens; the sub-field modulation coding element is a sixth lens (6); and the detector multiplexing assembly is a fourteenth lens (14). The air gap between the sixth lens (6) and the seventh lens (7) is 50.744 mm, the air gap between the seventh lens (7) and the eighth lens (8) is 20.644 mm, the air gap between the eighth lens (8) and the ninth lens (9) is 21.178 mm, the air gap between the ninth lens (9) and the tenth lens (10) is 99.725 mm, the air gap between the tenth lens (10) and the eleventh lens (11) is 20.722 mm, the air gap between the eleventh lens (11) and the twelfth lens (12) is 31.290 mm, the air gap between the twelfth lens (12) and the thirteenth lens (13) is 45.512 mm, and the air gap between the thirteenth lens (13) and the fourteenth lens (14) is 7 mm.

Images