Design method of image surface multiplication relay structure of wide spectral width and wide field high spectral imaging telescope

Abstract

This invention discloses a design method for a plane-multiplying relay structure of a wide-spectrum, wide-swath hyperspectral imaging telescope, relating to the field of optical design technology. The method includes establishing a model for realizing a controllable aberration-multiplying relay structure. This model consists of four closely related parts: field segmentation, plane multiplication, telecentricity adjustment, and field curvature / distortion adjustment. Based on this model, the interrelationships between the number of field segmentations, plane multiplication rate, image-side telecentricity adjustment, field curvature / distortion adjustment, and relay structure parameters of the hyperspectral imaging system are clarified. Based on these parameter relationships, a design method for the initial relay structure is further proposed. Using the plane-multiplying relay structure of this invention, wide-spectrum, wide-swath hyperspectral imaging is achieved, breaking through the technical bottleneck of traditional telescopes' difficulty in connecting multiple large-field-of-view spectrometers and large-scale detectors.

Description

Technical Field

[0001] This invention relates to the field of optical design technology, specifically to a large-image-plane low-distortion imaging technique method for relay coupling of a broadband hyperspectral imaging telescope with multiple spectrometers, and particularly to a design method for an image-plane multiplication relay structure for a broadband hyperspectral imaging telescope. Background Technology

[0002] Traditional spaceborne hyperspectral cameras suffer from narrow spatial and spectral coverage and low sensitivity, severely hindering their application in environmental, resource, and oil and gas emission monitoring. This is primarily because traditional hyperspectral imaging struggles to balance spatial and spectral coverage, resolution, and sensitivity. Specifically, for telescopes, multiple spectrometers and detectors need to be integrated within their orbital field of view to achieve broad-spectral detection. Wide-swath detection is achieved through a large field of view in the telescope's orbital direction. The wider the spectral range, the more fields of view need to be segmented along the orbital direction to accommodate more spectrometers and detectors. Furthermore, when the detector chip's size is insufficient to support a wide swath, the field of view needs to be further segmented along the telescope's orbital direction so that smaller detectors can be pieced together to create a wider field of view in the orbital direction. Therefore, hyperspectral imaging telescopes must possess not only a large field of view in the orbital direction for wide swath detection but also a large field of view along the orbital direction for broad spectral coverage. Meanwhile, to ensure a large observation range and high spatial resolution in both spatial and spectral dimensions, a greater number of pixels is required in both dimensions. Furthermore, with finer spatial and spectral resolution, large pixels and small F-numbers are needed to achieve a relatively large aperture and ensure high sensitivity, while telecentric imaging of the image plane is required to achieve low distortion and ensure high accuracy. Therefore, rectangular large image plane and small F-number telecentric imaging have become a fundamental requirement for spaceborne wide-swath, wide-spectrum hyperspectral imaging telescopes. Traditional paraxial optical imaging telescopes, affected by the sharp deterioration of distortion with the field of view according to the cubic and quintic polynomial relationship, struggle to simultaneously achieve rectangular large image plane and small F-number telecentric imaging in both spatial and spectral dimensions, and cannot achieve coupling and integration with multiple spectrometers and detectors in both spectral and spatial dimensions.

[0003] Achieving relay coupling between the telescope, spectrometer, and detector has become a crucial and primary technological challenge for spaceborne broadband hyperspectral imaging. Traditional relay structures only serve to divide the field of view and lack functions for adjusting field of view telecentrism, image distance, and aberrations, as well as the ability to effectively enlarge the telescope's image plane. For example, the 2011 domestic paper "Design of Optical System for Large Field-of-View High-Resolution Spaceborne Imaging Spectrometer" uses a "field-of-view separation structure + dichroic slice" approach to connect four spectrometer systems, achieving field-of-view and spectral band stitching. The 2020 international paper "MAVIS IFU with AO for VLT: image slicer concept and design" designed a field splitter that divides the field into two and images each subfield onto a slicer mirror array composed of slender mirrors, sending it in different directions so that it can be re-imaged side-by-side by another mirror array on the slit. The EnMap hyperspectral camera launched in 2022 uses a single-blade mirror relay structure to achieve a 24mm slit width and 24μm dual-strip field-of-view segmentation, connecting to spectrometers in the 0.4-1.0μm and 1.0-2.5μm spectral bands respectively, achieving broadband detection, but the swath width is only 30km.

[0004] In view of this, this invention proposes a telescope optical relay structure that adjusts parameters such as the telescope's image plane, telecentrism, and aberrations, effectively expanding the telescope's field of view in both the through-track and along-track directions. This overcomes the major technical bottleneck of traditional telescopes and relay structures, which struggle to achieve rectangular, large-image-plane, low-F-number telecentric imaging. It can increase the spectral width and swath width capabilities of spaceborne hyperspectral imaging by several times. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a design method for a relay structure for wide-spectrum, wide-swath hyperspectral imaging telescope image plane multiplication. It constructs the structure, model, and relational parameters for field segmentation, image plane multiplication, telecentric control, and field curvature / distortion aberration control, forming a complete parameter design system for the relay structure. This effectively controls the telecentricity, image distance, and aberrations of the spectral imaging telescope, achieving a near-order-of-magnitude multiplication of the telescope's spectral image plane. It solves the major challenge of docking and arranging multiple spectrometers and their large-scale mosaic detectors with the front telescope, opening a new path for spaceborne hyperspectral cameras to achieve wide-spectrum, wide-swath, high-resolution, high-sensitivity, and high-precision detection.

[0006] Therefore, the present invention adopts the following technical solution:

[0007] A design method for a relay structure for wide-spectrum, wide-swath hyperspectral imaging telescope image plane doubling is disclosed. The method includes: establishing a relay structure implementation model with controllable image plane doubling aberrations. This model comprises four models: field segmentation, image plane doubling, telecentric adjustment, and field curvature / distortion adjustment. The field segmentation model determines the parametric relationship between the hyperspectral imaging system image plane and the segmented field of view of the relay structure. The image plane doubling model determines the parametric relationship between the hyperspectral imaging system image plane and the doubled image plane of the relay structure. The telecentric adjustment model determines the parametric relationship between the image-side telecentricity of the hyperspectral imaging system and the relay structure. The field curvature / distortion adjustment model determines the parametric relationship between the field curvature / distortion of the hyperspectral imaging system image plane and the adjustment parameter relationship between the relay structure and the image plane. The relay structure is designed based on these parametric relationships.

[0008] Preferably, the field-of-view segmentation model is used to determine the parametric relationship between the image plane of the hyperspectral imaging system and the segmented field of view, wherein the relationship is:

[0009] ;

[0010] in, The minimum number of segments required for a spatial dimensional relay structure in a hyperspectral imaging system to divide the field of view. For the telescope's focal length, For the telescope's field of view, The number of available pixels in the spatial dimension of a single detector module. The size of the detector pixel; This represents the minimum number of fields of view segmented by the spectral relay structure in a hyperspectral imaging system. For the telescope's operating spectrum, This is the operating spectrum of a single-module detector; For the floor operation, For OR operation, This is the modulo operation.

[0011] Preferably, the image plane magnification model is used to determine the parametric relationship between the image plane and the magnified image plane of the hyperspectral imaging system, wherein the relationship is as follows:

[0012] ;

[0013] in, Here, |.| represents the image plane magnification rate of the relay structure, and |.| represents the modulo operation. For the image distance of the telescope's double-slit field of view, , For the telescope's focal length, This represents the difference in field of view between the two slits. The field of view of the first slit. The field of view of the first slit; The double-slit image plane after image plane multiplication by the relay structure Axis vectors , The spectral dispersion width, , This represents the number of spectral channels. The detector unit is the spatial length of the spectrometer. Allow space for detector encapsulation and splicing. , The distance from the outermost effective pixel to the edge after the detector is packaged. Minimum required spacing for detector splicing process; For the unused width of the detector, , denoted as the number of pixels in the spectral dimension of the detector.

[0014] Preferably, the telecentricity control model is used to determine the parametric relationship between the image-side telecentricity of the hyperspectral imaging system and the relay structure, wherein the relationship is:

[0015] ;

[0016] in, The telecentricity of the first slit field of view; The telecentricity of the second slit field of view; Let be the propagation vector of the principal ray of the first slit field of view between the second-order field-splitting mirror M3 and the first image-plane magnifying mirror M1. This is the unit vector corresponding to the direction of propagation. Let M1 be the propagation vector of the principal ray of the first slit field of view between the first image-plane magnifying lens M1 and the first slit M5. This is the unit vector corresponding to the direction of propagation. Let be the propagation vector of the principal ray of the second slit field of view between the second-stage field-splitting mirror M4 and the second image-plane magnifying mirror M2. The unit vector corresponding to the direction of propagation; Let M1 be the propagation vector of the principal ray of the second slit field of view between the second image-plane magnifying lens M2 and the second slit M6. This is the unit vector corresponding to the direction of propagation. For modulo operation. When the field of view is split into two secondary mirrors. Using a ridge prism reflector with a ridge angle designed to be 90°, the parametric relationship between the system's image-side telecentrism and the relay structure is as follows:

[0017] ;

[0018] Preferably, the field curvature / distortion control model is used to determine the parameter relationship between the field curvature / distortion of the image plane and the relay structure of the hyperspectral imaging system, and the relationship is as follows:

[0019] ;

[0020] in, For the field curvature of the center field of view of different strips in the system; Let be the defocusing amount of the center field of view of the m-th strip field of view of the telescope. This represents the defocusing amount of the center field of view of the nth strip field of view of the telescope. This represents the system strip field-of-view distortion value; For the principal rays of the telescope's strip field of view on the image plane To coordinates; The y-coordinate of the principal ray in the image plane after modulation by the relay structure in the optical path of the telescope strip field of view; For the telescope's focal length, This is the field of view for the telescope.

[0021] The present invention adopts the above technical solution and has the following beneficial effects:

[0022] This invention proposes a design method for a relay structure for image plane multiplication in a wide-spectrum, wide-swath hyperspectral imaging telescope. For the first time, it presents the key parameter relationships and optimization strategies for image plane multiplication, telecentric adjustment, and aberration control in the relay structure. It also realizes image plane multiplication, telecentric adjustment, and aberration control for the first time in the relay optics of a hyperspectral imaging telescope, breaking through the technical bottleneck of traditional telescopes that struggle to balance large rectangular image planes with low F-numbers and low distortion with high image quality. This invention opens up a new path for the design and application of telecentric imaging telescopes with large rectangular image planes and low F-numbers.

[0023] By innovatively constructing a quantitative relationship between image plane, aberration, and optical structure parameters, the complex mirror design problem of large image plane and low distortion in traditional telescopes is transformed into a problem of solving relay structure parameters. It has extremely strong image plane multiplication and aberration control characteristics. With only low-order optical lens combinations and optical path control, the design requirements for image plane multiplication and aberration control in different scenarios can be achieved.

[0024] The innovative combination of relay structure design and telescope optimization alleviates the telescope's requirements for telecentrism and aberration, resolving the significant contradiction between the telescope's large image plane and low distortion design and its engineering implementation, and achieving several times the improvement in image plane, telecentrism, and aberration.

[0025] The designed image-multiplying relay structure allows the telescope to expand its field of view along the track while maintaining the field of view in the track-crossing direction. This enables the use of small-area array detectors in spectrometers, overcoming the bottleneck of limited detector chip size. Furthermore, by setting the relay structure mirrors as even-order aspherical or freeform surfaces and independently optimizing the segmented strip field of view, the telescope's image plane can be further expanded, providing an effective technical means for broadband-wide swath, high spatial-hyperspectral-high radiometric resolution, and high sensitivity-high precision hyperspectral imaging. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the design method for a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging according to the present invention.

[0027] Figure 2 This is a schematic diagram of the field-of-view segmentation model and parameter relationships of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging according to the present invention.

[0028] Figure 3 This is a schematic diagram of the image plane multiplication model and parameter relationships of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging according to the present invention.

[0029] Figure 4 This is a schematic diagram illustrating the modulation of wavefront aberrations on the image plane of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging according to the present invention.

[0030] Figure 5 This is a schematic diagram of the telecentric control model and parameter relationships of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging according to the present invention.

[0031] Figure 6 This is a schematic diagram of the field curvature / distortion control model and parameter relationships of a telescope image plane doubling relay structure for broadband and wide-swath hyperspectral imaging according to the present invention.

[0032] Figure 7 This is a schematic diagram illustrating the effect of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging on the telescope image plane control according to the present invention.

[0033] Figure 8 This is an example of a telescope image plane multiplication relay structure for wide-spectrum and wide-swath hyperspectral imaging according to the present invention, and an effect diagram on the image plane control of the telescope system.

[0034] Figure 9 This is a schematic diagram comparing the effects of the telescope image plane multiplication relay structure of the present invention (wideband and wide-swath hyperspectral imaging) and traditional methods on the telescope image plane size (through track × along track) and photon collection capability (F#).

[0035] Figure 10This is a schematic diagram of a second embodiment of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging according to the present invention.

[0036] Figure 11 This is a schematic diagram of a second embodiment of the telescope image plane multiplication relay structure for wide-spectrum and wide-swath hyperspectral imaging according to the present invention, showing 6-channel field-of-view segmentation and image plane multiplication.

[0037] Figure 12 This is a schematic diagram illustrating the implementation of image plane multiplication and multi-dimensional image plane control in Embodiment 2 of the telescope image plane multiplication relay structure for wide-spectrum and wide-swath hyperspectral imaging according to the present invention.

[0038] Figure 13 This is a schematic diagram illustrating the image plane segmentation and the application of different band detectors in broadband and wide-swath hyperspectral imaging, as part of a second embodiment of the telescope image plane multiplication relay structure of the present invention.

[0039] Figure 14 This is a schematic diagram illustrating the image plane segmentation of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging, as well as the application of spectrometers with different spectroscopic capabilities in broadband and wide-swath detection, according to Embodiment 2 of the present invention. Detailed Implementation

[0040] To make the objectives, features and advantages of the present invention clearer, a more detailed description of one specific embodiment of the present invention will be provided. In the following description, many specific details are set forth in order to provide a full understanding of the present invention. However, the present invention can be practiced in many other ways different from those described, and therefore the present invention is not limited to the specific embodiments disclosed below.

[0041] Before providing a further detailed description of the present invention, the terms and concepts used in this invention are explained, and the terms and concepts used in this invention shall be interpreted as follows:

[0042] (1) System image plane: The system image plane refers to the image plane of a traditional telescope after being controlled by the relay structure proposed in this invention, and is not the same as the image plane of a traditional telescope;

[0043] (2) Image plane doubling: refers to the effective enlargement of the telescope image plane through the relay structure of the present invention. The image plane enlarged several times can meet the ideal connection between multiple spectrometers and telescopes;

[0044] (3) Image-side telecentric: refers to the fact that the principal rays of the converging cones in different fields of view are all perpendicular to the image plane;

[0045] (4) Telecentric controllable: This means that the optical relay structure of the present invention can adjust the light rays converged on the image plane by the telescope, so that the principal rays of the light cones in different fields of view are as perpendicular to the image plane as possible;

[0046] (5) Controllable aberrations: This refers to the optical relay structure of the present invention controlling the optical path difference and direction between the imaging strip fields of different spectrometers, thereby achieving optimized and adjustable aberrations such as field curvature and distortion of the image plane in different strip fields;

[0047] (6) Light-gathering capability: refers to the ability of an optical telescope to collect signals on the system's image plane, including the range and magnitude of the signals. It is represented by the product of the system's image plane area, diopter, and optical aperture area.

[0048] (7) Diopter: refers to the ability of a spectral imaging system to converge or diverge light, and is expressed as the reciprocal of the system's focal length.

[0049] (8) F number: refers to the relative optical aperture of a spectral imaging system, which is expressed as the product of the system diopter and the optical aperture. The smaller the F number, the larger the relative optical aperture.

[0050] (9) Swath width: refers to the width of the ground imaging covered by the spectral imaging system in the spatial dimension, which is determined by the telescope field of view, the spectrometer field of view and the size of the detector spatial dimension pixels, etc., which are perpendicular to the satellite's orbital direction.

[0051] (10) Spectral width: refers to the wavelength width covered by the spectral imaging system in the spectral dimension, which is determined by the telescope field of view parallel to the satellite's orbital direction (which determines the number of spectrometer docking points), the spectrometer dispersion width, and the size of the detector's spectral dimension pixels, etc.

[0052] The relay structure, acting as a bridge between the front telescope and the rear spectrometer in a hyperspectral imaging system, plays a crucial role in hyperspectral imaging. Hyperspectral imaging collects and converges the signal of a strip of ground data onto the image plane via a telescope. A long, narrow slit is placed on the image plane, its length corresponding to its swath width (typically tens of millimeters), and its width being the size of a single pixel (typically tens of micrometers). This relay structure determines the field of view of the ground feature strip input to the spectrometer.

[0053] The relay structure of this invention uses a reflector as a field-of-view segmentation device, which can cover the entire field of view and the entire spectrum without losing optical signal energy. It should be noted that hyperspectral imaging is only one application scenario of this application, but this application is not limited thereto. The specific method is as follows:

[0054] refer to Figure 1This is a schematic flowchart of a design method for a relay structure for wide-spectrum, wide-swath hyperspectral imaging telescope image plane doubling according to the present invention. The method includes: establishing a relay structure implementation model with controllable aberrations due to image plane doubling; the image plane doubling model includes four models: field segmentation, image plane doubling, telecentric adjustment, and field curvature / distortion adjustment; the field segmentation model is used to determine the parameter relationship between the image plane of the hyperspectral imaging system and the segmented field of view of the relay structure; the image plane doubling model is used to determine the parameter relationship between the image plane of the hyperspectral imaging system and the doubled image plane of the relay structure; the telecentric adjustment model is used to determine the parameter relationship between the image-side telecentricity of the hyperspectral imaging system and the relay structure; and the field curvature / distortion adjustment model is used to determine the parameter relationship between the field curvature / distortion of the image plane of the hyperspectral imaging system and the adjustment of the relay structure; and the relay structure design is implemented based on the above parameter relationships.

[0055] refer to Figure 2 This is a schematic diagram of the field-of-view segmentation model and parameter relationships of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging according to the present invention. The field-of-view segmentation model is used to determine the parameter relationships between the system image plane and the segmented strip field of view. The relationships are as follows:

[0056] ;

[0057] in, The minimum number of segments required for a spatial dimensional relay structure in a hyperspectral imaging system to divide the field of view. For the telescope's focal length, For the telescope's field of view, The number of available pixels in the spatial dimension of a single detector module. The size of the detector pixel; This represents the minimum number of fields of view segmented by the spectral relay structure in a hyperspectral imaging system. For the telescope's operating spectrum, This is the operating spectrum of a single-module detector; For the floor operation, For OR operation, This is the modulo operation.

[0058] Preferably, the minimum number of segments in the field of view of the spatial relay structure of the hyperspectral imaging system is [not specified]. The determination process is as follows:

[0059] 1) In At that time, then for By performing a rounding operation, the minimum number of fields of view segmented by the spatial dimensional relay structure is obtained. ;

[0060] 2) In At that time, then for After rounding down and adding 1, we obtain the minimum number of fields of view to be segmented by the spatial dimensional relay structure. ;

[0061] The minimum number of fields of view segmented by the spectral relay structure in the hyperspectral imaging system. The determination process is as follows:

[0062] 1) In When = 0, then for Performing a rounding operation yields the minimum number of fields of view segmented by the spectral dimensional relay structure. ;

[0063] 2) In At that time, then for After rounding down and adding 1, we obtain the minimum number of fields of view to be segmented by the spectral dimensional relay structure. .

[0064] refer to Figure 3 This is a schematic diagram of the image plane multiplication model and parameter relationships of a telescope image plane multiplication relay structure for wide-spectrum and wide-swath hyperspectral imaging according to the present invention. The image plane multiplication model is used to determine the parameter relationship between the system image plane and the multiplied image plane, and the relationship is as follows:

[0065] ;

[0066] in, Here, |.| represents the image plane magnification rate of the relay structure, and |.| represents the modulo operation. For the image distance of the telescope's double-slit field of view, The double-slit image plane after image plane multiplication by the relay structure Axis vectors;

[0067] Image distance of the telescope's double slit field of view:

[0068] ;

[0069] in, For the telescope's focal length, This represents the difference in field of view between the two slits. The field of view of the first slit. The field of view of the first slit; the The selection needs to be based on the zenith angle of the second-order field-of-view splitter. Telescope focal length and system The number is used to determine and select the best option, generally taking , >2.

[0070] The double-slit image plane after relay structure image plane multiplication Axis vectors:

[0071] ;

[0072] in, The spectral dispersion width, , This represents the number of spectral channels. The detector unit is the spatial length of the spectrometer. Allow space for detector encapsulation and splicing. , The distance from the outermost effective pixel to the edge after the detector is packaged. Minimum required spacing for detector splicing process; For the unused width of the detector, , The number of pixels in the spectral dimension of the detector; by adjusting , The parameter size can be adjusted to achieve detectors of different specifications. )and Matching between them This is the operating spectrum for a single-module detector.

[0073] Then the image plane multiplication rate of the relay structure is:

[0074] ;

[0075] When in When this occurs, it indicates that the image plane of the system's telescope is magnified in that direction. When this occurs, it indicates that the image plane of the system telescope is reduced in that direction.

[0076] refer to Figure 4 This is a schematic diagram illustrating the modulation of wavefront aberrations on the image plane of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging according to the present invention. The modulation process of wavefront aberrations on the image plane of the hyperspectral imaging system by the relay structure is as follows:

[0077] ;

[0078] The image magnification of the relay structure is the ratio of the minimum field-of-view image size of the telescopes before and after the relay structure to achieve the same wide swath and wide spectral detection capability. It reflects the relay structure's ability to control the telescope's wide swath and wide spectral detection capability and can be considered a scaling factor for the telescope's equivalent field of view H. Adjusting the image magnification of the relay structure... As the height H of the field of view realized by the system increases, it is relatively reduced, making... The value decreases, thus realizing the system wavefront aberration. Decrease; when adjusting the relay structure image plane magnification rate When the height H of the field of view achieved by the system is reduced, it is relatively magnified. Increasing the value of realizes the wavefront aberration of the system. This scaling effect on the field of view, in turn, affects the magnitude of aberration changes with the field of view. For example, for Aberration terms (such as astigmatism) equal to 2, when When it is twice the original value, it resembles a scattered term. Return to the original state The astigmatism will be significantly reduced, which is equivalent to using Like scattered ( The field of view enables aberration control for H-field-of-view detection.

[0079] in, For aberration coefficients, This represents the radial position of the exit pupil, i.e., the radially normalized coordinates. This is the azimuth angle of the exit pupil plane, i.e., the circumferential position of the pupil plane; For example, high dependency order; The order of radial dependence of the pupil; Let be the order of pupil circumferential dependence.

[0080] refer to Figure 5 This is a schematic diagram of the telecentric control model and parameter relationship of a telescope image plane multiplication relay structure for broadband and wide-swath hyperspectral imaging according to the present invention. The telecentric control model is used to determine the parameter relationship between the system image-side telecentricity and the relay structure. The relationship is as follows:

[0081] ;

[0082] in, The telecentricity of the first slit field of view; The telecentricity of the second slit field of view; Let be the propagation vector of the principal ray of the first slit field of view between the second-order field-splitting mirror M3 and the first image-plane magnifying mirror M1. This is the unit vector corresponding to the direction of propagation. Let M1 be the propagation vector of the principal ray of the first slit field of view between the first image-plane magnifying lens M1 and the first slit M5. This is the unit vector corresponding to the direction of propagation. Let be the propagation vector of the principal ray of the second slit field of view between the second-stage field-splitting mirror M4 and the second image-plane magnifying mirror M2. The unit vector corresponding to the direction of propagation; Let M1 be the propagation vector of the principal ray of the second slit field of view between the second image-plane magnifying lens M2 and the second slit M6. This is the unit vector corresponding to the direction of propagation. For modulo operations. Preferably, the field-of-view secondary splitting mirror... Using a ridge prism reflector with a ridge angle designed to be 90°, the parametric relationship between the system's image-side telecentrism and the relay structure is as follows:

[0083] ;

[0084] in, The telecentricity of the first slit field of view; For the telecentricity of the second slit field of view, Let M1 be the propagation vector of the principal ray of the first slit field of view between the first image-plane magnifying lens M1 and the first slit M5. This is the unit vector corresponding to the direction of propagation. Let M1 be the propagation vector of the principal ray of the second slit field of view between the second image-plane magnifying lens M2 and the second slit M6. This is the unit vector corresponding to the direction of propagation.

[0085] Preferably, the process of controlling the system image-side telecentricity according to the telecentricity control model is as follows:

[0086] 1) Calculate the initial telecentricity of the first and second slit fields of view based on the telecentric control model. ;

[0087] 2) Based on the system design requirements and application scenario, determine the target telecentricity values ​​for the first and second slit fields of view. ;

[0088] 3) Adjust the image plane magnifying lens by a certain step size. and Rotation angle of the shaft and The adjusted propagation vector of the principal ray of the first slit field of view between the first image-plane magnifying lens M1 and the first slit M5 is obtained. And the propagation vector of the principal ray of the second slit field of view between the second image plane magnifying lens M2 and the second slit M6. ;

[0089] 4) with and As input, the adjusted telecentricity is calculated based on the telecentric control model. and ;

[0090] 5) Calculation , With the target value of centrifugality The difference:

[0091] ;

[0092] 6) Determine if and If all values ​​are less than the preset error threshold, the centrifugal force adjustment is considered to have reached the target, and the adjustment is stopped; otherwise, the adjustment continues. Repeat the above steps until the centrifugal force adjustment reaches the target value.

[0093] refer to Figure 6 This is a schematic diagram illustrating the field curvature / distortion control model and parameter relationships of a telescope image plane doubling relay structure for broadband and wide-swath hyperspectral imaging according to the present invention. The field curvature / distortion control model is used to determine the parameter relationships between the system image plane field curvature / distortion and the relay structure, and the relationships are as follows:

[0094] ;

[0095] in, The field curvature of the center field of view of different strips of the system, i.e. the optical path difference between the best image planes, is ideally taken to be 0; Let be the defocusing amount of the center field of view of the m-th strip field of view of the telescope. This represents the defocusing amount of the center field of view of the nth strip field of view of the telescope. This represents the system strip field-of-view distortion value; For the principal rays of the telescope's strip field of view on the image plane The coordinate system is ideally constant. The y-coordinate of the principal ray in the image plane after modulation by the relay structure in the optical path of the telescope strip field of view; For the telescope's focal length, This is the field of view for the telescope.

[0096] Preferably, the field curvature of the center field of view of different strips in the system is adjusted according to the field curvature / distortion control model. The regulation process is as follows:

[0097] 1) Obtain the center field defocus of different strip fields of view of the initial structure. ,in The number of stripes, ; Calculate the central field curvature of different striped fields of view :

[0098] ;

[0099] 2) Based on the optical path distribution between the first image plane magnifying lens, the second field-of-view splitting lens, and the slits in the relay structure, the optical path difference between the three is adjusted to satisfy the following relationship, thereby realizing the control of the field curvature of the double-slit field of view image plane by the relay structure:

[0100] ;

[0101] in, The optical path length of the first principal ray with field of view propagating between the first image plane magnifying lens and the second-order field-split lens. The optical path length of the second principal ray with field of view propagating between the second image-plane magnifying lens and the second-order field-of-view splitter is given. The optical path length of the first principal ray with field of view propagating between the first image-plane magnifying lens and the double slits on the image plane. The optical path length between the second field-of-view first image plane magnifying lens and the double slits on the image plane.

[0102] 3) Repeat the above steps, continuously measure the optical path difference, analyze and adjust the relay structure parameters, and perform iterative optimization until the field curvature meets the design specifications and requirements;

[0103] Preferably, the system strip field curvature value is determined according to the field curvature / distortion control model. The regulation process is as follows:

[0104] 1) Calculate the field curvature value at each field of view location using the following formula:

[0105] ;

[0106] in, To obtain the ideal y-coordinates of the principal ray of the telescope's strip field of view on the image plane, This represents the y-coordinate of the principal ray in the image plane after modulation by the relay structure in the telescope's strip field of view. For different field of view positions; For the telescope's focal length, For the telescope's field of view;

[0107] 2) Calculate the strip bending values ​​obtained from all fields of view. By comparing the values, the maximum value is found, which is the field-of-view curvature value of the telescope strip. :

[0108] ;

[0109] 3) The calculated telescope strip field of view is bent If the distortion value is compared with the system design requirement, the relay structure is considered to have successfully controlled the distortion of the telescope strip; if it is not, the space-dimensional field-of-view splitting mirror in the relay structure is fine-tuned, and the above steps are repeated until the distortion value required by the system design is met.

[0110] refer to Figure 7 This is a schematic diagram illustrating the effect of a telescope image plane multiplication relay structure on telescope image plane control in the context of the present invention: without the relay structure, the image plane is small and diffusion distortion is severe (e.g., Figure 7 As shown in (a), the relay structure achieves a telecentric large image plane and low diffusion distortion (e.g. Figure 7 As shown in (b), based on the field-of-view segmentation function of the relay structure, an image plane multiplication function is added to multiply the image plane spacing of the telescope strip field of view, so as to meet the requirements of the multispectral and multi-specification detector splicing layout in wide-spectrum and wide-swath hyperspectral detection for a large image plane of the telescope; a telecentric adjustment function is added to independently adjust the telecentric angle of the strip field of view segmented by the telescope, so that the principal ray of each strip field of view is as perpendicular as possible to the telescope image plane (the telescope image plane is the object plane of the rear optical spectrometer), thereby improving the influence of the telescope field of view image-side telecentricity on the spectral imaging of the rear optical spectrometer, while reducing the telescope telecentricity requirement and making it easier to achieve a larger field of view and a larger image plane; an aberration adjustment function is added to segmentally adjust the optical path path and propagation direction of each strip field of view, thereby improving the field curvature and strip distortion between the telescope strip fields of view. In summary, by adding image plane multiplication, telecentric adjustment, and aberration control to the relay structure, the development difficulty of the broadband wide-swath telescope will be reduced, the coupling between the telescope and the spectrometer will be improved, and low-distortion, low-diffusion, large-image-plane hyperspectral imaging can be effectively achieved.

[0111] refer to Figure 8 This is an example of a broadband, wide-swath hyperspectral imaging telescope image plane multiplication relay structure according to the present invention, and an effect diagram on the image plane adjustment of the telescope system. The hyperspectral imaging system telescope has an F=2.83 focal length. =708mm, pixel size 30μm×30μm, RMS radius of the diffuse spot ≤1 / 2 pixel, stripe curvature ≤0.2 pixel, double slit field of view spacing d=16mm. The relay structure doubles the image plane of the first and second slit fields of view along the track direction from 4.95mm to 16mm, and achieves high image-side telecentrism and focal plane consistency of the double slit field of view optical path through the telecentric adjustment structure, giving the telescope stronger rear optical layout capabilities.

[0112] To achieve the goal of "larger swath, wider spectrum, and smaller F-number" for hyperspectral imaging telescopes, Table 1 presents the test results of the optical capabilities of the telescopes at the track-crossing image plane, along the track image plane, and minimum F-number using relay structures implemented with and without this invention (conventional method).

[0113] Table 1. Impact of using the relay structure of this invention on the telescope image plane and parameters of the high-light camera system.

[0114]

[0115] Scenario 1: Improved image plane (swath width) along the track: Under the basic constraints of "diffusion spot ≤ 5μm, image-side telecentric angle ≤ 0.5°, strip curvature ≤ 3μm, optical length ≤ 565mm, back working distance ≥ 90mm, focal length = 708mm, F# = 2.83", the image plane along the track is fixed at 45mm. The traditional low-order mirror image plane along the track is only 9.9mm. The image plane along the track of low-order mirrors in this method is increased to 64.3mm, and the swath width is increased by 6.49 times compared with the traditional low-order mirrors. The traditional high-order mirror image plane along the track is 74.2mm. The image plane along the track of high-order mirrors in this method is further expanded to 156.3mm, and the swath width is increased by 2.11 times compared with the traditional high-order mirrors.

[0116] Scenario 2: Improvement of image plane (spectral width) along the track: Under the basic constraints of "diffusion spot ≤ 5μm, image-side telecentric angle ≤ 0.5°, strip curvature ≤ 3μm, optical length ≤ 565mm, back working distance ≥ 90mm, focal length = 708mm, F# = 2.83", when the through-track image plane is fixed at 64.3mm, the traditional low-order mirror image plane along the track is 22.6mm, while the image plane along the track of low-order mirrors in this method is improved to 45mm; when the through-track image plane is fixed at 156.3mm, the traditional high-order mirror image plane along the track is 22.6mm, while the image plane along the track of high-order mirrors in this method is improved to 45mm.

[0117] Scenario 3: Improved Minimum F-Number (Relative Aperture): Under the basic constraints of "diffusion spot ≤ 5μm, image-side telecentric angle ≤ 0.5°, stripe curvature ≤ 3μm, optical length ≤ 565mm, back working distance ≥ 90mm, focal length = 708mm", with a fixed image plane of 64.3mm along the track and 45mm across the track, the traditional F-number for low-order mirrors is 4.05, while this method can achieve an F-number of 2.83 for low-order mirrors; with a fixed image plane of 156.3mm along the track and 45mm across the track, the traditional F-number for high-order mirrors is 4.29, while this method can achieve an F-number of 2.83 for high-order mirrors. The telescope's light-gathering capability is significantly enhanced compared to traditional methods.

[0118] refer to Figure 9 This diagram illustrates the comparison between the telescope image plane doubling relay structure for wide-spectrum hyperspectral imaging according to the present invention and traditional methods on the size of the telescope image plane (through-track × along-track) and the photon collection capability (F#). Based on the telescope optical capability data in Table 1, the diagram shows the influence of the present invention's method on the telescope's signal collection range (through-track swath width, along-track spectral width) and photon collection capability (F#). It demonstrates that the present invention's method can make the hyperspectral imaging system telescope image plane larger and wider in the through-track direction, larger and wider in the along-track direction, with a smaller F number and stronger photon collection capability.

[0119] Table 2 compares the wide-spectrum and wide-swath hyperspectral imaging system based on the telescope image plane multiplication relay structure of this invention with the traditional hyperspectral imaging system in terms of wide-spectrum and wide-swath signal collection capability (SICV). The results show that the signal collection capability of the hyperspectral imaging system using the relay structure of this method is 1.99 to 6.49 times that of the traditional method.

[0120] Table 2 Comparison of wide-spectrum and wide-swath signal collection capabilities between the hyperlight camera system using the relay structure of this invention and the traditional hyperspectral imaging system.

[0121]

[0122] refer to Figure 10 This is a schematic diagram of a second embodiment of a wide-spectrum, wide-swath hyperspectral imaging telescope image plane multiplication relay structure according to the present invention. The relay structure 30 includes: two sets of first-stage field-of-view splitters 31, a first-stage field-of-view splitter frame structure 32, three sets of second-stage field-of-view splitters 33, an image plane multiplication common reference base 34, six sets of image plane multipliers 35, an image plane multiplier frame 36, three sets of dual-field-of-view slit stops 37, a slit contamination protection window 38, and a common reference structure skeleton 39. (Reference) Figure 11 This is a schematic diagram of a second embodiment of the telescope image plane multiplication relay structure for wide-spectrum and wide-swath hyperspectral imaging according to the present invention, illustrating a 6-path field-of-view splitting and image plane multiplication. The spaceborne hyperspectral imaging system telescope converges six different field-of-view beams, which then pass through a slit contamination protection window. Slits 1 and 2, and 5 and 6, are two sets of field-of-view beam paths that pass through a first-stage field-of-view splitter 31 and a second-stage field-of-view splitter 33, respectively. Slits 3 and 4 pass directly through another set of second-stage field-of-view splitters 33, resulting in the required striped field-of-view beam paths. The three split striped field-of-view beam paths are reflected by the corresponding field-of-view image plane multiplier 35 and enter the dual-field-of-view slit aperture 37 to obtain the slit striped field-of-view exit light. (Reference) Figure 12 This is a schematic diagram illustrating image plane multiplication and multi-dimensional image plane control in Embodiment 2 of the telescope image plane multiplication relay structure for wide-spectrum and wide-swath hyperspectral imaging according to the present invention. Based on the principles and mechanisms of field-of-view splitting, image plane multiplication, and image plane control, image plane multiplication and multi-dimensional image plane control are achieved through the coordinated design of the field-of-view splitting mirror 33 and the field-of-view image plane multiplier 35. Image plane multiplication is achieved by splitting the incident light by the field-of-view splitting mirror 33 and reflecting and modulating the light by the field-of-view image plane multiplier 35, multiplying the image plane length d1 along the track of slits 1 and 2 to D2, the image plane length d2 along the track of slits 3 and 4 to D2, and the image plane length d3 along the track of slits 5 and 6 to D3. Expanded layout space: By combining the modulation effect of the two sets of field-of-view first-level split mirrors 31, the original same-side layout of d1, d2, and d3 is transformed into a three-way layout of D1, D2, and D3, which not only doubles the image plane but also greatly expands the layout space of the subsequent optical system.

[0123] refer to Figure 13 This diagram illustrates the image plane segmentation and application of a wide-spectrum, wide-swath hyperspectral imaging telescope image plane multiplication relay structure according to Embodiment 2 of the present invention, as well as the configuration of different band detectors in wide-spectrum, wide-swath detection. Here, n1 represents the spatial dimension specification of detector model M1, n2 represents the spatial dimension specification of detector model M2, and n3 represents the spatial dimension specification of detector model M3. The relay structure segments a large image plane for the front telescope strip field of view, supporting the stitching of multiple small-scale detectors, effectively achieving wide-swath detection with a single large-scale detector. This overcomes the bottleneck of telescope detection swath width being limited by detector specifications, while the image plane multiplication significantly reduces the telescope's along-track field of view requirements and design complexity. In practical applications, flexible configurations can be made according to detector specifications, requirements, and economic conditions. For example, for spatial dimension detection requirements of a 2000 yuan M-type detector, it can be achieved by stitching together two 1024 yuan M-1 type detectors, or four 512 yuan M-2 type detectors, or by flexibly combining one 1024 yuan M-1 type detector and two 512 yuan M-2 type detectors.

[0124] refer to Figure 14 This is a schematic diagram illustrating the image plane segmentation of a relay structure for a wide-spectrum, wide-swath hyperspectral imaging telescope, as described in Embodiment 2 of the present invention, and its application in configuring spectrometers with different dispersive capabilities for wide-spectrum, wide-swath detection. The relay structure segments a large image plane with a front telescope strip field of view, supporting spectrometers with multiple different dispersive capabilities. Wide-spectrum, high-spectral detection is achieved through spectral wavelength stitching. Spectrometer 1 is connected to the field of view optical path of slit 1 for fine dispersive spectroscopy. Spectrometer 2 docking slit 2 field of view optical path, fine spectral dispersion Spectrometer 3 docking slit 3 field of view optical path, fine spectral dispersion Spectrometer with 4 docking slits and 4 field-of-view optical paths for fine spectral dispersion. Spectrometer 5 docking slit 5 field of view optical path, fine spectral dispersion The spectrometer features a 6-slit docking system with a 6-field optical path for fine spectral dispersion. Where: 1) n, m, p, q are positive integers greater than 1, representing the spectral channel numbers of the system, for example... 1) Indicates the spectral channel n with center wavelength λ; 2) Generally, 1 to 2 spectral channels are connected between adjacent spectra of spectrometer 1 to spectrometer 6 to achieve the continuity of the system spectrum.

[0125] It should be noted that, Figure 13 , 14The invention demonstrates the implementation of detector stitching, spectrometer stitching, and structural parameters using a 6-channel field of view, but this invention is not limited thereto. The specific number and spatial relationship of the field of view optical path segmentation, image plane multiplication, aberration, and telecentric control components can be set according to actual needs. For example, in some implementations, there is only one optical path, which does not involve image plane multiplication, but this application is not limited thereto.

[0126] Table 3 shows the performance parameters of the telescope and the image plane control effect in the hyperspectral imaging system using the relay structure of this invention. In this embodiment, the basic parameters of the telescope are: F-number 3.0, focal length 708mm, and the field of view range of the six slits (slit 1 to slit 6) along the track is -0.3° to 2.6°. When the system is not equipped with the relay structure of this invention: the image distance is 5.561mm to 4.951mm; the telecentricity of the central field of view is 0.22° to 1.22°, with large fluctuations in telecentricity; the focal plane consistency is 1μm to 1.3μm, with obvious focal plane deviation. When the system is equipped with the relay structure of this invention, precise control of the image plane is achieved: the image distance is increased to 11.003mm to 16.066mm, the telecentricity of the central field of view is optimized to 0°, and the telecentricity consistency is significantly improved; the focal plane consistency is optimized to 0μm (completely consistent).

[0127] Table 3 Performance parameters and image plane adjustment results of the hyperspectral camera telescope using the relay structure of this invention

[0128]

[0129] In summary, this invention proposes a telescope image plane multiplication relay structure for achieving wide-spectrum, wide-swath hyperspectral imaging. This structure allows the telescope to expand its field of view along the track direction while maintaining the field of view in the track-crossing direction. This makes it possible to use small-area array detectors in spectrometers, overcoming the bottleneck of limited detector chip size. Furthermore, by setting the relay structure mirrors as even-order aspherical or freeform surfaces and independently optimizing the segmented strip field of view, the telescope's image plane can be further expanded. This breaks through the technical bottleneck of traditional telescopes, which struggle to balance large rectangular image planes with low F-numbers and low distortion with high image quality. It pioneers a new path for the design and application of telescopes with large rectangular image planes and low F-numbers at telecentric imaging. It achieves several-fold improvements in image plane, telecentricity, and aberrations, providing an effective technical means for wide-spectrum, wide-swath, high spatial-hyperspectral-high radiometric resolution, and high sensitivity-high precision hyperspectral imaging. The solution provided by this invention has enabled the telescope optical relay structure of the hyperspectral imaging system to promote the leapfrog development of spaceborne hyperspectral imaging, strongly supported the successful development of the world's first spaceborne wide-spectrum and wide-swath hyperspectral camera, and significantly promoted the technological progress of hyperspectral remote sensing in fields such as environmental ecology, climate change, and resource agriculture.

[0130] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for an image plane multiplication relay structure of a broadband wide-swath hyperspectral imaging telescope, characterized in that: The method includes: establishing a controllable relay structure implementation model for image plane doubling aberration, wherein the image plane doubling aberration controllable relay structure implementation model includes four models: field segmentation, image plane doubling, telecentric adjustment, and field curvature / distortion adjustment; the field segmentation model is used to determine the parameter relationship between the image plane of the hyperspectral imaging system and the segmented field of view of the relay structure; the image plane doubling model is used to determine the parameter relationship between the image plane of the hyperspectral imaging system and the doubled image plane of the relay structure; the telecentric adjustment model is used to determine the parameter relationship between the image-side telecentricity of the hyperspectral imaging system and the relay structure; and the field curvature / distortion adjustment model is used to determine the parameter relationship between the field curvature / distortion of the image plane of the hyperspectral imaging system and the adjustment of the relay structure; and the relay structure is designed based on the above parameter relationships.

2. The design method for the image plane multiplication relay structure of the broadband wide-swath hyperspectral imaging telescope according to claim 1, characterized in that: The field-of-view segmentation model is used to determine the parametric relationship between the image plane of the hyperspectral imaging system and the segmented field of view of the relay structure. The relationship is as follows: ； in, The minimum number of segments required for a spatial dimensional relay structure in a hyperspectral imaging system to divide the field of view. For the telescope's focal length, For the telescope's field of view, The number of available pixels in the spatial dimension of a single detector module. The size of the detector pixel; This represents the minimum number of fields of view segmented by the spectral relay structure in a hyperspectral imaging system. For the telescope's operating spectrum, This is the operating spectrum of a single-module detector; For the floor operation, For OR operation, This is the modulo operation.

3. The design method for the image plane multiplication relay structure of the broadband wide-swath hyperspectral imaging telescope according to claim 2, characterized in that: The minimum number of spatial relay structures in the hyperspectral imaging system to segment the field of view The determination process is as follows: 1) In At that time, then for By performing a rounding operation, the minimum number of fields of view segmented by the spatial dimensional relay structure is obtained. ; 2) In At that time, then for After rounding down and adding 1, we obtain the minimum number of fields of view to be segmented by the spatial dimensional relay structure. ; The minimum number of fields of view segmented by the spectral dimension relay structure of the hyperspectral imaging system The determination process is as follows: 1) In When = 0, then for Performing a rounding operation yields the minimum number of fields of view segmented by the spectral dimensional relay structure. ; 2) In At that time, then for After rounding down and adding 1, we obtain the minimum number of fields of view to be segmented by the spectral dimensional relay structure. .

4. The design method for the image plane multiplication relay structure of the broadband wide-swath hyperspectral imaging telescope according to claim 1, characterized in that: The image plane doubling model is used to determine the parametric relationship between the image plane of the hyperspectral imaging system and the image plane multiplied by the relay structure. The relationship is as follows: ； in, Here, |.| represents the image plane magnification rate of the relay structure, and |.| represents the modulo operation. For the image distance of the telescope's double-slit field of view, The double-slit image plane after image plane multiplication by the relay structure Axis vectors; Image distance of the telescope's double slit field of view: ； in, For the telescope's focal length, This represents the difference in field of view between the two slits. The field of view of the first slit. The field of view of the second slit; Double-slit image plane after relay structure image plane multiplication Axis vectors: ； in, The spectral dispersion width, , This represents the number of spectral channels. The detector unit is the spatial length of the spectrometer. Allow space for detector encapsulation and splicing. , The distance from the outermost effective pixel to the edge after the detector is packaged. Minimum required spacing for detector splicing process; For the unused width of the detector, , The number of pixels in the spectral dimension of the detector; Then the image plane multiplication rate of the relay structure is: ； When in When this occurs, it indicates that the image plane of the system's telescope is magnified in that direction. When this occurs, it indicates that the image plane of the system telescope is reduced in that direction.

5. The design method for the image plane multiplication relay structure of the broadband wide-swath hyperspectral imaging telescope according to claim 4, characterized in that: The process by which the relay structure modulates the wavefront aberration of the hyperspectral imaging system is as follows: ； Adjusting the image plane magnification rate of the relay structure As the height H of the field of view realized by the system increases, it is relatively reduced, making... The value decreases, thus realizing the system wavefront aberration. Decrease; when adjusting the relay structure image plane magnification rate When the height H of the field of view achieved by the system is reduced, it is relatively magnified. Increasing the value of realizes the wavefront aberration of the system. Increase; in, For aberration coefficients, This represents the radial position of the exit pupil, i.e., the radially normalized coordinates. This is the azimuth angle of the exit pupil plane, i.e., the circumferential position of the pupil plane; For example, high dependency order; The order of radial dependence of the pupil; Let be the order of pupil circumferential dependence.

6. The design method for the image plane multiplication relay structure of the broadband wide-swath hyperspectral imaging telescope according to claim 1, characterized in that: The telecentricity control model is used to determine the parametric relationship between the image-side telecentricity of the hyperspectral imaging system and the relay structure. The relationship is as follows: ； in, The telecentricity of the first slit field of view; The telecentricity of the second slit field of view; Let be the propagation vector of the principal ray of the first slit field of view between the second-order field-splitting mirror M3 and the first image-plane magnifying mirror M1. This is the unit vector corresponding to the direction of propagation. Let M1 be the propagation vector of the principal ray of the first slit field of view between the first image-plane magnifying lens M1 and the first slit M5. This is the unit vector corresponding to the direction of propagation. Let be the propagation vector of the principal ray of the second slit field of view between the second-stage field-splitting mirror M4 and the second image-plane magnifying mirror M2. The unit vector corresponding to the direction of propagation; Let M1 be the propagation vector of the principal ray of the second slit field of view between the second image-plane magnifying lens M2 and the second slit M6. This is the unit vector corresponding to the direction of propagation. This is a modulo operation.

7. The design method for the image plane multiplication relay structure of the broadband wide-swath hyperspectral imaging telescope according to claim 6, characterized in that: The field-of-view splitter Using a ridge prism reflector with a ridge angle designed to be 90°, the parametric relationship between the system's image-side telecentrism and the relay structure is as follows: ； in, The telecentricity of the first slit field of view; For the telecentricity of the second slit field of view, Let M1 be the propagation vector of the principal ray of the first slit field of view between the first image-plane magnifying lens M1 and the first slit M5. This is the unit vector corresponding to the direction of propagation. Let M1 be the propagation vector of the principal ray of the second slit field of view between the second image-plane magnifying lens M2 and the second slit M6. This is the unit vector corresponding to the direction of propagation.

8. The design method for the image plane multiplication relay structure of the broadband wide-swath hyperspectral imaging telescope according to claim 6 or 7, characterized in that: The process of controlling the system's image-side telecentricity according to the telecentricity control model is as follows: 1) Calculate the initial telecentricity of the first and second slit fields of view based on the telecentric control model. ; 2) Based on the system design requirements and application scenario, determine the target telecentricity values ​​for the first and second slit fields of view. ; 3) Adjust the image plane magnifying lens by a certain step size. Angle of rotation of the axis The adjusted propagation vector of the principal ray of the first slit field of view between the first image-plane magnifying lens M1 and the first slit M5 is obtained. And the propagation vector of the principal ray of the second slit field of view between the second image plane magnifying lens M2 and the second slit M6. ; 4) with and As input, the adjusted telecentricity is calculated based on the telecentric control model. and ; 5) Calculation , With the target value of centrifugality The difference: ； 6) Determine if and If all values ​​are less than the preset error threshold, the centrifugal force adjustment is considered to have reached the target, and the adjustment is stopped; otherwise, the adjustment continues. Repeat the above steps until the centrifugal force adjustment reaches the target value.

9. The design method for the image plane multiplication relay structure of the broadband wide-swath hyperspectral imaging telescope according to claim 1, characterized in that: The field curvature / distortion control model is used to determine the parameter relationship between the field curvature / distortion of the image plane and the relay structure in a hyperspectral imaging system. The relationship is as follows: ； in, For the field curvature of the center field of view of different strips in the system; Let be the defocusing amount of the center field of view of the m-th strip field of view of the telescope. This represents the defocusing amount of the center field of view of the nth strip field of view of the telescope. This represents the system strip field-of-view distortion value; For the principal rays of the telescope's strip field of view on the image plane To coordinates; The y-coordinate of the principal ray in the image plane after modulation by the relay structure in the optical path of the telescope strip field of view; For the telescope's focal length, This is the field of view for the telescope.

10. The design method for the image plane multiplication relay structure of the broadband wide-swath hyperspectral imaging telescope according to claim 9, characterized in that: Field curvature of the central field of view of different strips in the system was determined according to the field curvature / distortion control model. The regulation process is as follows: 1) Obtain the center field defocus of different strip fields of view of the initial structure. ,in The number of stripes, ; Calculate the central field curvature of different strip fields of view : ； 2) Based on the optical path distribution between the first image plane magnifying lens, the second field-of-view splitting lens, and the slits in the relay structure, the optical path difference between the three is adjusted to satisfy the following relationship, thereby realizing the control of the field curvature of the double-slit field of view image plane by the relay structure: ； in, The optical path length of the first principal ray with field of view propagating between the first image plane magnifying lens and the second-order field-split lens. The optical path length of the second principal ray with field of view propagating between the second image-plane magnifying lens and the second-order field-of-view splitter is given. The optical path length of the first principal ray with field of view propagating between the first image-plane magnifying lens and the double slits on the image plane. The optical path length between the second field-of-view first image plane multiplier and the double slits on the image plane; 3) Repeat the above steps, continuously measure the optical path difference, analyze and adjust the relay structure parameters, and perform iterative optimization until the field curvature meets the design specifications and requirements.

11. The design method of the image plane multiplication relay structure for a broadband wide-swath hyperspectral imaging telescope according to claim 9, characterized in that: The system strip field curvature value was determined according to the field curvature / distortion control model. The regulation process is as follows: 1) Calculate the field curvature value at each field of view location using the following formula: ； in, To obtain the ideal y-coordinates of the principal ray of the telescope's strip field of view on the image plane, This represents the y-coordinate of the principal ray in the image plane after modulation by the relay structure in the telescope's strip field of view. For different field of view positions; For the telescope's focal length, For the telescope's field of view; 2) Calculate the strip bending values ​​obtained from all fields of view. By comparing the values, the maximum value is found, which is the field-of-view curvature value of the telescope strip. : ； 3) The calculated telescope strip field of view is bent If the distortion value is compared with the system design requirement, the relay structure is considered to have successfully controlled the distortion of the telescope strip; if it is not, the space-dimensional field-of-view splitting mirror in the relay structure is fine-tuned, and the above steps are repeated until the distortion value required by the system design is met.

12. A broadband, wide-swath hyperspectral imaging telescope image plane multiplication relay structure, characterized in that, The telescope image plane multiplication relay structure for achieving the broadband and wide-swath hyperspectral imaging is designed and implemented by the method described in any one of claims 1 to 11.

13. A broadband hyperspectral imaging system, characterized in that, The image plane multiplication relay structure of a broadband hyperspectral imaging telescope as described in claim 12 is used.

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