Common-aperture common-view-field full-wave-band image space scanning hyperspectral imaging system

Abstract

The invention discloses a common-caliber common-view-field full-wave-band image space scanning hyperspectral imaging system which comprises a first main reflecting mirror, a view field eliminating stray light diaphragm, a secondary reflecting mirror, an image space scanning mirror, a turning reflecting mirror, a front color separation film, an imaging system, a rear color separation film and a spectrograph. A middle primary imaging off-axis two-reflection structure is adopted to realize large-aperture light path compression and collimation, an image space scanning mirror is arranged at an outgoing pupil, image space small-aperture scanning replaces an object space large-aperture scanning mirror to scan spectrum imaging to the ground, and the lightweight design of the system is realized; through twice light splitting arrangement of the front color separation film and the rear color separation film, a full-wave band spectrum is subdivided into eight common-view-field channels, a detection wave band can cover ultraviolet to very long wave infrared, and the bottleneck that different wave bands of an ultra-wide spectrum in a traditional mode cannot share the caliber and the view field is broken through; the problem that the size and the weight of a system are too large due to the adoption of an object-space large-aperture scanning mirror is solved, and regional full-spectrum hyperspectral image data in a staring mode are obtained.

Description

Technical Field

[0001] The invention relates to remote sensing imaging technology, and in particular to a common aperture common field of view full-band image square scanning hyperspectral imaging system. Background Art

[0002] Hyperspectral imaging technology simultaneously collects geometric, radiation and spectral information of materials to form an image cube. While imaging the material, hundreds or thousands of continuous and precise radiation intensity data of different wavelengths are obtained within a wide spectrum range to form the spectral characteristic curve "fingerprint" of the material, which can effectively realize the identification of the material. Satellite-borne hyperspectral imaging technology can obtain complex surface spectral component information of hundreds of thousands of square kilometers within a few minutes, which strongly supports the fine classification and detection and identification of ground object components in large areas. Therefore, satellite-borne hyperspectral imaging has great scientific research and application value in energy resource exploration, environmental disaster monitoring, agricultural and forestry remote sensing, greenhouse gas monitoring, urban investigation and other aspects.

[0003] In recent years, with the successful development and launch of wide-spectrum and wide-width visible short-wave infrared hyperspectral cameras for earth remote sensing payloads of the GF-5 and Ziyuan-1 series of hyperspectral satellites, a large number of visible to short-wave infrared band spectrum data of substances have been applied and displayed, confirming the huge application potential of hyperspectral spectrum detection in material identification. Given that the reflection and spontaneous radiation bands of objects cover the ultraviolet to very long-wave infrared bands, it is urgent to study the spectrum characteristics of substances in the full band range and establish a spectral library to support the application of hyperspectral data. In addition, the rapid and efficient acquisition of full-spectrum hyperspectral data of substances in a complete area in the staring mode is another leapfrog development demand of hyperspectroscopy. However, the ultra-large coverage and ultra-large aperture satellite-borne full-band image scanning hyperspectral imaging system covers an ultra-wide range of 0.3 to 16 microns from ultraviolet to very long-wave infrared, and there is currently a lack of effective technical means. Summary of the invention

[0004] The present invention proposes a common-aperture common-field-of-view full-band image-space scanning hyperspectral imaging system, which can be applied to airborne or satellite-borne multi-band, full-band hyperspectral ground imaging monitoring, and aims to meet the demand for efficient acquisition of full-band spectrum data of maneuverable and flexible moving materials, and solve the problems of small space for engineering layout of full-band hyperspectral at the current stage, time-sharing acquisition of full-band data, large-aperture object-space scanning mirror envelope size, and inability to meet the requirements of multi-spectrometer module docking, one-time capture of maneuverable moving materials, and simultaneous acquisition of full-band data.

[0005] Embodiments of the present invention provide a common-aperture and common-field-of-view full-band image-plane scanning hyperspectral imaging system. The system includes a first primary mirror 1, an out-of-field stray light stop 2, a secondary mirror 3, an image-plane scanning mirror 4, a folding mirror 5, a front dichroic filter, an imaging system, a rear dichroic filter, and a spectrometer. The out-of-field stray light stop 2 is located at the intermediate image plane formed by the first primary mirror 1 and the secondary mirror 3; the image-plane scanning mirror 4 is located at the exit pupil plane formed by the first primary mirror 1 and the secondary mirror 3; the front dichroic filter includes a first dichroic filter 6-1, a second dichroic filter 6-2, and a third dichroic filter 6-3; the first dichroic filter 6-1 reflects ultraviolet-visible light and transmits infrared light, the second dichroic filter 6-2 reflects near-infrared-shortwave infrared light and transmits mid-wave-very long-wave infrared light, the third dichroic filter 6-3 reflects mid-wave-long wave infrared light and transmits long wave-very long-wave infrared light; the first dichroic filter 6-1, the second dichroic filter 6-2, and the third dichroic filter 6-3 are all located in the common-field-of-view collimated optical path formed by the first primary mirror 1 and the secondary mirror 3; the imaging system includes a first imaging system 7-1, a second imaging system 7-2, a third imaging system 7-3, and a fourth imaging system 7-4; the rear dichroic filter includes a fourth dichroic filter 8-1, a fifth dichroic filter 8-2, a sixth dichroic filter 8-3, and a seventh dichroic filter 8-4; the fourth dichroic filter 8-1 reflects ultraviolet light and transmits visible light, the fifth dichroic filter 8-2 reflects near-infrared light and transmits shortwave infrared light, the sixth dichroic filter 8-3 reflects mid-wave infrared light and transmits long-wave infrared first-band light, the seventh dichroic filter 8-4 reflects long-wave infrared second-band light and transmits very long-wave infrared light; Light rays from the object space are converged by the first primary mirror 1 onto the out-of-field stray light stop 2, then collimated by the secondary mirror 3 and the pupil is reduced, and then reflected by the image-plane scanning mirror 4 and the folding mirror 5 to the front dichroic filter, passing through the first dichroic filter 6-1, the second dichroic filter 6-2, and the third dichroic filter 6-3 in sequence to form four optical channels of ultraviolet-visible light, near-infrared-shortwave infrared light, mid-wave-long wave infrared light, and long wave-very long-wave infrared light; The ultraviolet light - visible light is converged and imaged by the first imaging system 7 - 1, and then two optical channels of ultraviolet light and visible light are formed through the fourth dichroic filter 8 - 1; the near - infrared - short - wave infrared light is converged and imaged by the second imaging system 7 - 2, and then two optical channels of near - infrared light and short - wave infrared light are formed through the fifth dichroic filter 8 - 2; the mid - wave - long - wave infrared light is converged and imaged by the third imaging system 7 - 3, and then two optical channels of mid - wave infrared light and long - wave infrared first - band light are formed through the sixth dichroic filter 8 - 3; the long - wave - very - long - wave infrared light is converged and imaged by the fourth imaging system 7 - 4, and then two optical channels of long - wave infrared second - band light and very - long - wave infrared light are formed through the seventh dichroic filter 8 - 4; thus, the four optical channels in the full band are further divided into eight channels, forming eight independent imaging common - field focal planes, which are docked with the eight spectrometers to form a hyperspectral imaging system with common aperture, common - field and full - band image - side scanning.

[0006] For the common - aperture, common - field and full - band image - side scanning hyperspectral imaging system according to an embodiment of the present invention, the system further includes a rear catadioptric mirror 10, and the long - wave - very - long - wave infrared light enters the fourth imaging system 7 - 4 after the optical path is refracted by the rear catadioptric mirror 10.

[0007] For the common - aperture, common - field and full - band image - side scanning hyperspectral imaging system according to an embodiment of the present invention, the first primary mirror 1 and the secondary mirror 3 are off - axis paraboloidal reflectors.

[0008] For the common - aperture, common - field and full - band image - side scanning hyperspectral imaging system according to an embodiment of the present invention, the rotation axis of the image - side scanning mirror 4 is perpendicular to the meridian plane and coincides with the exit pupil plane formed by the first primary mirror 1 and the secondary mirror 3. By rotating the image - side scanning mirror 4, the field of view of the telescope system composed of the first primary mirror 1 and the secondary mirror 3 can be changed, and the variable field of view in the object space can be converted into a fixed field of view in the image space.

[0009] For the common - aperture, common - field and full - band image - side scanning hyperspectral imaging system according to an embodiment of the present invention, the size of the image - side scanning mirror 4 is less than or equal to 1 / 10 of the size of the first primary mirror 1.

[0010] For the common - aperture, common - field and full - band image - side scanning hyperspectral imaging system according to an embodiment of the present invention, the material of the front dichroic filter is zinc selenide; the first dichroic filter 6 - 1 can achieve high reflection in the ultraviolet - visible light band and high transmission in the near - infrared - very - long - wave infrared light band; the second dichroic filter 6 - 2 can achieve high reflection in the near - short - wave infrared light band and high transmission in the mid - wave - very - long - wave infrared light band; the third dichroic filter 6 - 3 can achieve high reflection in the mid - wave - long - wave infrared light and high transmission in the long - wave - very - long - wave infrared light band.

[0011] According to the co-aperture co-field-of-view full-band image-plane scanning hyperspectral imaging system of an embodiment of the present invention, the material of the rear dichroic filter is fused quartz and zinc selenide. The fourth dichroic filter 8-1 can achieve high reflection in the ultraviolet band and high transmission in the visible light band; the fifth dichroic filter 8-2 can achieve high reflection in the near-infrared band and high transmission in the short-wave infrared band; the sixth dichroic filter 8-3 can achieve high reflection in the mid-wave infrared band and high transmission in the long-wave infrared first band; the seventh dichroic filter 8-4 can achieve high reflection in the long-wave infrared second band and high transmission in the very long-wave infrared band.

[0012] According to the co-aperture co-field-of-view full-band image-plane scanning hyperspectral imaging system of an embodiment of the present invention, the band range of the ultraviolet light is 0.2 μm to 0.4 μm; the visible light band range is 0.4 μm to 0.75 μm; the near-infrared light band range is 0.75 μm to 1.4 μm; the short-wave infrared light band range is 1.4 μm to 2.7 μm; the mid-wave infrared light band range is 2.7 μm to 5.0 μm; the long-wave infrared first band range is 5.0 μm to 9.0 μm; the long-wave infrared second band range is 9.0 μm to 12.5 μm; the very long-wave infrared light band range is 12.5 μm to 16 μm.

[0013] According to the co-aperture co-field-of-view full-band image-plane scanning hyperspectral imaging system of an embodiment of the present invention, the imaging systems are all off-axis three-reflection imaging modules. The first imaging system 7-1, the second imaging system 7-2, the third imaging system 7-3, and the fourth imaging system 7-4 are all modularly designed and have the same mirror parameters.

[0014] According to the co-aperture co-field-of-view full-band image-plane scanning hyperspectral imaging system of an embodiment of the present invention, the spectroscopic layout module 0 composed of the front dichroic filter, the imaging system, the rear dichroic filter, the spectrometer, and the rear catadioptric mirror 10 is rotated 90° as a whole along the Z axis, which can reduce the volume of the hyperspectral imaging system.

[0015] The present invention adopts the above technical solutions, and the advantages are as follows: 1) By adopting an intermediate one-time image-plane off-axis two-reflection collimation structure, on the premise of ensuring that the optical entrance pupil diameter remains unchanged, the optical scale behind the secondary mirror is reduced by nearly ten times; a field stop is set at the intermediate one-time image plane, which not only realizes the efficient suppression of off-field stray light, but also provides a solution for simplifying the design difficulty and scale of a large-aperture light shield. 2) The exit pupil is led out and an image-plane scanning mirror is set, converting the large-aperture object-plane scanning into a small-aperture image-plane scanning, and the scale reduction reaches more than an order of magnitude, providing a solution for the lightweight design of a hyperspectral imaging detection system with a meter-level aperture. 3) By combining a dichroic filter in front of the collimated optical path, an off-axis three-mirror imaging module, and a dichroic filter with a long back working distance at the rear, eight channels with a common field of view are achieved, expanding the detection engineering layout space in the full spectral band under the same aperture and common field of view. The detection wavelength band under the same aperture and common field of view covers the entire ultra-wide range from ultraviolet to very long wave infrared; 4) The full spectral band same aperture and common field of view hyperspectral design provides a novel solution for the rapid acquisition of regional hyperspectral data in the staring mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. is a schematic structural diagram of a same aperture and common field of view full-band image plane scanning hyperspectral imaging system according to the present invention.

[0017] Figure 2 FIG. is a schematic structural diagram of a compact implementation of a same aperture and common field of view full-band image plane scanning hyperspectral imaging system according to the present invention.

[0018] Figure 3 FIG. is a schematic diagram of the principle of eliminating stray light outside the field of view by the stray light diaphragm of a same aperture and common field of view full-band image plane scanning hyperspectral imaging system according to the present invention.

[0019] Figure 4 FIG. shows a schematic diagram of increasing the field of view imaging of the image plane scanning structure of a same aperture and common field of view full-band image plane scanning hyperspectral imaging system according to the present invention and a partial enlarged view of the image plane scanning structure.

[0020] Figure 5 FIG. is a schematic diagram of increasing the field of view imaging of the traditional object plane large aperture scanning structure adopted by the hyperspectral imaging system in the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0021] In order to make the objectives, features, and advantages of the present invention clearer, the following provides a more detailed description of a specific implementation manner of the present invention in conjunction with the accompanying drawings and embodiments. However, the present invention can be implemented in many other ways different from the described ones. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0022] According to the same aperture and common field of view full-band image plane scanning hyperspectral imaging system described in the present invention, a spaceborne ultraviolet to very long wave infrared hyperspectral imager system is designed, and the image quality is close to the diffraction limit.

[0023] First, in conjunction with the accompanying drawings, an embodiment of a same aperture and common field of view full-band image plane scanning hyperspectral imaging system disclosed in the present application is described. Refer to Figure 1 and Figure 2 , which is a schematic structural diagram of a same aperture and common field of view full-band image plane scanning hyperspectral imaging system according to the present invention, Figure 2This is a schematic diagram of the compact implementation structure of a common-aperture, common-field-of-view, full-band image-plane scanning hyperspectral imaging system according to the present invention. The system includes: a first primary mirror 1, an out-of-field stray light stop 2, a secondary mirror 3, an image-plane scanning mirror 4, a folding mirror 5, a front dichroic filter, an imaging system, a rear dichroic filter, and a spectrometer. The out-of-field stray light stop 2 is located at the intermediate image plane formed by the first primary mirror 1 and the secondary mirror 3; the image-plane scanning mirror 4 is located at the exit pupil formed by the first primary mirror 1 and the secondary mirror 3; the front dichroic filter includes a first dichroic filter 6-1, a second dichroic filter 6-2, and a third dichroic filter 6-3; the first dichroic filter 6-1 reflects ultraviolet-visible light and transmits infrared light, the second dichroic filter 6-2 reflects near-infrared-shortwave infrared light and transmits mid-wave-very long-wave infrared light, and the third dichroic filter 6-3 reflects mid-wave-long wave infrared light and transmits long wave-very long-wave infrared light; the first dichroic filter 6-1, the second dichroic filter 6-2, and the third dichroic filter 6-3 are all located in the common-field-of-view collimated optical path formed by the first primary mirror 1 and the secondary mirror 3; the imaging system includes a first imaging system 7-1, a second imaging system 7-2, a third imaging system 7-3, and a fourth imaging system 7-4; the rear dichroic filter includes a fourth dichroic filter 8-1, a fifth dichroic filter 8-2, a sixth dichroic filter 8-3, and a seventh dichroic filter 8-4; the fourth dichroic filter 8-1 reflects ultraviolet light and transmits visible light, the fifth dichroic filter 8-2 reflects near-infrared light and transmits shortwave infrared light, the sixth dichroic filter 8-3 reflects mid-wave infrared light and transmits long-wave infrared first-band light, and the seventh dichroic filter 8-4 reflects long-wave infrared second-band light and transmits very long-wave infrared light.

[0024] Light rays from the object space are converged by the first primary mirror 1 onto the out-of-field stray light stop 2. Figure 3 This is a schematic diagram of the principle of the out-of-field stray light elimination effect of the out-of-field stray light stop in a common-aperture, common-field-of-view, full-band image-plane scanning hyperspectral imaging system according to the present invention. Refer to Figure 3 , the out-of-field stray light stop 2 can effectively eliminate out-of-field stray light; then, the light rays are collimated by the secondary mirror 3 and the pupil is reduced, and then reflected by the image-plane scanning mirror 4 and the folding mirror 5 to the front dichroic filter, and successively pass through the first dichroic filter 6-1, the second dichroic filter 6-2, and the third dichroic filter 6-3 to form four optical channels of ultraviolet-visible light, near-infrared-shortwave infrared light, mid-wave-long wave infrared light, and long wave-very long-wave infrared light; Ultraviolet light - visible light is converged and imaged by the first imaging system 7-1, and then passes through the fourth dichroic filter 8-1 to form two optical channels for ultraviolet light and visible light; near-infrared - short-wave infrared light is converged and imaged by the second imaging system 7-2, and then passes through the fifth dichroic filter 8-2 to form two optical channels for near-infrared light and short-wave infrared light; mid-wave - long-wave infrared light is converged and imaged by the third imaging system 7-3, and then passes through the sixth dichroic filter 8-3 to form two optical channels for mid-wave infrared light and long-wave infrared first-band light; long-wave - very long-wave infrared light is converged and imaged by the fourth imaging system 7-4, and then passes through the seventh dichroic filter 8-4 to form two optical channels for long-wave infrared second-band light and very long-wave infrared light; in this way, the four optical channels in the full band are further divided into eight channels, forming eight independent imaging common fields of view on the focal plane, which are docked with eight spectrometers to form a hyperspectral imaging system with common aperture, common field of view, and full-band image-side scanning. The eight spectrometers include: ultraviolet spectrometer 9-1, visible spectrometer 9-2, near-infrared spectrometer 9-3, short-wave infrared spectrometer 9-4, mid-wave infrared spectrometer 9-5, long-wave infrared first-band spectrometer 9-6, long-wave infrared second-band spectrometer 9-7, and very long-wave infrared spectrometer 9-8.

[0025] According to an embodiment of the present application, the system further includes a rear catadioptric mirror 10, and the long-wave - very long-wave infrared light enters the fourth imaging system 7-4 after the optical path is refracted by the rear catadioptric mirror 10.

[0026] Figure 4 Schematic diagram of increasing the field of view imaging of the image-side scanning structure of a common aperture, common field of view, full-band image-side scanning hyperspectral imaging system of the present invention, as well as a partial enlarged view of the image-side scanning structure. According to an embodiment of the present application, as Figure 4 shown, the rotation axis of the image-side scanning mirror 4 is perpendicular to the meridian plane and coincides with the exit pupil plane formed by the first primary mirror 1 and the secondary mirror 3. By rotating the image-side scanning mirror 4, the field of view of the telescope system composed of the first primary mirror 1 and the secondary mirror 3 can be changed, and the variable field of view in the object space can be converted into a fixed field of view in the image space.

[0027] According to an embodiment of the present application, the size of the image-side scanning mirror 4 is less than or equal to 1 / 10 of the size of the first primary mirror 1. Figure 5 Schematic diagram of increasing the field of view imaging of the traditional object-side large-aperture scanning structure adopted by the hyperspectral imaging system in the prior art. As Figure 5 shown, in the prior art, the traditional object-side large-aperture scanning mirror 11 of the hyperspectral imaging system is combined with the static turning mirror 4-1 to form a large field of view imaging, and it is necessary for the size of the object-side large-aperture scanning mirror 11 to be more than 1.42 times the size of the second primary mirror 1-1 to achieve. And by adopting the technical solution of the present invention, the small-aperture image-side scanning mirror is directly used to replace the traditional object-side large-aperture scanning mirror 11 and the static turning mirror 4-1, realizing the lightweight design of the hyperspectral imaging detection system with a meter-level aperture.

[0028] To describe the embodiments more clearly, the specific technical indicators involved in the embodiments are listed herein. Considering that the spectrometer and the main optics are modular ideal imaging modules respectively, and the system integration can be achieved only through simple docking, so only the design indicators of the main optical system are listed in the example indicators. The specific technical indicators are as follows: Satellite orbital altitude: 800 km; Spectral range: Ultraviolet 0.2 μm - 0.4 μm; Visible 0.4 μm - 0.75 μm; Near-infrared 0.75 μm - 1.4 μm; Short-wave infrared 1.4 μm - 2.7 μm; Medium-wave infrared 2.7 μm - 5.0 μm; Long-wave infrared first band 5.0 μm - 9.0 μm; Long-wave infrared second band 9.0 μm - 12.5 μm; Very long-wave infrared 12.5 μm - 16 μm; Telescope clear aperture: 1650 mm; Relative aperture: 1:3.6; Focal length: 5940 mm; Sweep field of view: 0.2°; Image-side scan field of view: 0.06°; The specific design parameters are shown in Table 1.

[0029] Table 1

[0030]

[0031]

[0032] d1: The distance between the first primary mirror 1 and the secondary mirror 3; d2: The distance from the secondary mirror 3 to the image-side scan mirror 4; d3: The distance between the image-side scan mirror 4 and the folding mirror 5; d4: The distance from the folding mirror 5 to the front surface of the first dichroic filter 6-1; d5-1 / 2: The distance from the reflecting surface of the first dichroic filter 6-1 for the ultraviolet and visible light channels to the first off-axis three-mirror imaging module (the first imaging system 7-1); d6-1 / 2: The distance between the first mirror 7-1-1 and the second mirror 7-1-2 of the first off-axis three-mirror imaging module; d7-1 / 2: The distance between the second mirror 7-1-2 and the third mirror 7-1-3 of the first off-axis three-mirror imaging module; d8-1 / 2: The distance from the third mirror 7-1-3 of the first off-axis three-mirror imaging module to the reflecting surface of the fourth dichroic filter 8-1; d9-1: Distance from the reflecting surface of the fourth dichroic filter 8-1 to the slit of the ultraviolet spectrometer 9-1; d9-2: Thickness of the fourth dichroic filter 8-1; d10-2: Distance from the transmitting surface of the fourth dichroic filter 8-1 to the slit of the visible spectrometer 9-2; d5-3 / 4 / 5 / 6 / 7 / 8: Thickness of the first dichroic filter 6-1 shared by the six channels of near-infrared to very long-wave infrared; d6-3 / 4 / 5 / 6 / 7 / 8: Distance from the rear surface of the first dichroic filter 6-1 to the second dichroic filter 6-2; d7-3 / 4: Distance from the reflecting surface of the second dichroic filter 6-2 for the two channels of near-infrared and short-wave infrared to the off-axis three-reflection imaging module (the second imaging system 7-2); d8-3 / 4: Distance from the first mirror 7-2-1 of the second off-axis three-reflection imaging module to the second mirror 7-2-2 of the second off-axis three-reflection imaging module; d9-3 / 4: Distance from the second mirror 7-2-2 of the second off-axis three-reflection imaging module to the third mirror 7-2-3 of the second off-axis three-reflection imaging module; d10-3 / 4: Distance from the third mirror 7-2-3 of the second off-axis three-reflection imaging module to the reflecting surface of the fifth dichroic filter 8-2; d11-3: Distance from the reflecting surface of the fifth dichroic filter 8-2 to the slit of the near-infrared spectrometer 9-3; d11-4: Thickness of the fifth dichroic filter 8-2; d12-4: Distance from the transmitting surface of the fifth dichroic filter 8-2 to the slit of the short-wave infrared spectrometer 9-4; d7-5 / 6 / 7 / 8: Thickness of the second dichroic filter 6-2 shared by the four channels of mid-wave infrared to very long-wave infrared; d8-5 / 6 / 7 / 8: Distance from the rear surface of the second dichroic filter 6-2 to the third dichroic filter 6-3 that reflects the mid-wave to long-wave infrared first band and transmits the long-wave infrared second band to very long-wave infrared; d9-5 / 6: Distance from the reflecting surface of the third dichroic filter 6-3 for the two channels of mid-wave infrared and long-wave infrared first band to the off-axis three-reflection imaging module (the third imaging system 7-3); d10-5 / 6: Distance from the first mirror 7-3-1 of the third off-axis three-reflection imaging module to the second mirror 7-3-2 of the third off-axis three-reflection imaging module; d11-5 / 6: Distance from the second mirror 7-3-2 of the third off-axis three-reflection imaging module to the third mirror 7-3-3 of the third off-axis three-reflection imaging module; d12-5 / 6: The distance from the third mirror 7-3-3 of the third off-axis three-mirror imaging module to the reflecting surface of the sixth dichroic filter 8-3 that reflects mid-wave infrared light and transmits long-wave infrared first-band light; d13-5: The distance from the reflecting surface of the sixth dichroic filter 8-3 to the slit of the mid-wave infrared spectrometer 9-5; d13-6: The thickness of the sixth dichroic filter 8-3; d14-6: The distance from the transmitting surface of the sixth dichroic filter 8-3 to the slit of the long-wave infrared first-band spectrometer 9-6; d9-7 / 8: The thickness of the third dichroic filter 6-3 shared by the long-wave infrared second-band - very long-wave infrared two channels; d10-7 / 8: The distance from the rear surface of the third dichroic filter 6-3 to the long-wave infrared second-band - very long-wave turning mirror (rear catadioptric mirror 10); d11-7 / 8: The distance from the long-wave infrared second-band - very long-wave turning mirror (rear catadioptric mirror 10) to the off-axis three-mirror imaging module (the fourth imaging system 7-4); d12-7 / 8: The distance from the first mirror 7-4-1 of the fourth off-axis three-mirror imaging module to the second mirror 7-4-2 of the fourth off-axis three-mirror imaging module; d13-7 / 8: The distance from the second mirror 7-4-2 of the fourth off-axis three-mirror imaging module to the third mirror 7-4-3 of the fourth off-axis three-mirror imaging module; d14-7 / 8: The distance from the third mirror 7-4-3 of the fourth off-axis three-mirror imaging module to the reflecting surface of the seventh dichroic filter 8-4 that reflects long-wave infrared first-band light and transmits very long-wave infrared light; d15-7: The distance from the reflecting surface of the seventh dichroic filter 8-4 to the slit of the long-wave infrared second-band spectrometer 9-7; d15-8: The thickness of the seventh dichroic filter 8-4; d16-8: The distance from the transmitting surface of the seventh dichroic filter 8-4 to the slit of the very long-wave infrared spectrometer 9-8; R1: The radius of curvature of the first primary mirror 1; R2: The radius of curvature of the secondary mirror 3; R3: The radius of curvature of the first mirror 7-1-1 of the first off-axis three-mirror imaging module, the first mirror 7-2-1 of the second off-axis three-mirror imaging module, and the first mirror 7-3-1 of the third off-axis three-mirror imaging module; R4: The radius of curvature of the second mirror 7-1-2 of the first off-axis three-mirror imaging module, the second mirror 7-2-2 of the second off-axis three-mirror imaging module, and the second mirror 7-3-2 of the third off-axis three-mirror imaging module; R5: The radius of curvature of the third mirror 7-1-3 of the first off-axis three-mirror imaging module, the third mirror 7-2-3 of the second off-axis three-mirror imaging module, and the third mirror 7-3-3 of the third off-axis three-mirror imaging module; In this application, the selected spectrometer indicators are shown in Table 2 below: Table 2

[0033] According to an embodiment of the present application, the first primary mirror 1 and the secondary mirror 3 are off-axis reflective mirrors with a rotational paraboloid surface.

[0034] According to an embodiment of the present application, the material of the front dichroic filter is zinc selenide; the first dichroic filter 6-1 can achieve high reflection in the ultraviolet-visible light band and high transmission in the near-infrared-very long-wave infrared light band; the second dichroic filter 6-2 can achieve high reflection in the near-short-wave infrared light band and high transmission in the mid-wave-very long-wave infrared light band; the third dichroic filter 6-3 can achieve high reflection in the mid-wave-long wave infrared light and high transmission in the long wave-very long-wave infrared light band.

[0035] According to an embodiment of the present application, the material of the rear dichroic filter is fused quartz and zinc selenide. The fourth dichroic filter 8-1 can achieve high reflection in the ultraviolet light band and high transmission in the visible light band; the fifth dichroic filter 8-2 can achieve high reflection in the near-infrared light band and high transmission in the short-wave infrared light band; the sixth dichroic filter 8-3 can achieve high reflection in the mid-wave infrared light band and high transmission in the long-wave infrared first-band light; the seventh dichroic filter 8-4 can achieve high reflection in the long-wave infrared second-band light and high transmission in the very long-wave infrared light band.

[0036] According to an embodiment of the present application, the imaging systems are all off-axis three-mirror imaging modules. The first imaging system 7-1, the second imaging system 7-2, the third imaging system 7-3, and the fourth imaging system 7-4 are all modularly designed. Among them, between the first mirror 7-1-1 of the first off-axis three-mirror imaging module, the first mirror 7-2-1 of the second off-axis three-mirror imaging module, and the first mirror 7-3-1 of the third off-axis three-mirror imaging module, between the second mirror 7-1-2 of the first off-axis three-mirror imaging module, the second mirror 7-2-2 of the second off-axis three-mirror imaging module, and the second mirror 7-3-2 of the third off-axis three-mirror imaging module, and between the third mirror 7-1-3 of the first off-axis three-mirror imaging module, the third mirror 7-2-3 of the second off-axis three-mirror imaging module, and the third mirror 7-3-3 of the third off-axis three-mirror imaging module, the parameters are the same. Batch production can be achieved.

[0037] According to an embodiment of the present application, the spectroscopic layout module 0 composed of a front dichroic filter, an imaging system, a rear dichroic filter, a spectrometer, and a rear catadioptric mirror 10 is rotated 90° as a whole along the Z-axis, which can reduce the volume of the hyperspectral imaging system and achieve a compact design.

[0038] The common-aperture and common-field-of-view all-band image-space scanning hyperspectral imaging system of the present application uses an off-axis two-reflection structure with intermediate single imaging to achieve nearly ten-fold compression and collimation of a large-aperture optical path, and the exit pupil is led out; a small-aperture scanning mirror is set at the off-axis two-reflection exit pupil to achieve small-aperture image-space scanning to replace large-aperture object-space ground scanning spectroscopic imaging; three zinc selenide dichroic filters are used to divide the all-band into four common-field-of-view small spectral bands, and modular off-axis three-reflection is respectively used for focusing imaging into four common-field-of-view channels. Ultra-thin dichroic filters are respectively set at the working distances behind the off-axis three-reflection to further divide the spectral band into eight common-field-of-view channels. While providing sufficient layout space for modular docking of multiple spectrometers, it realizes the common-field-of-view design of all spectral channels, breaking through the bottleneck that the common-aperture and common-field-of-view of multiple spectrometers required for the full spectral band in the traditional method cannot be achieved and the large cost of introducing a large-size object-space scanning mirror in object-space scanning. The simulation experiment results show that the imaging quality of each wavelength within the Nyquist frequency is close to the diffraction limit. It realizes the simultaneous acquisition of all-band spectral map data of a high-speed moving object with a single exposure, and combines design examples to prove the feasibility of the system, which will provide a novel technical method for the realization of regional all-band hyperspectral imaging detection in the staring mode.

[0039] The above has described the embodiments of the present application in detail with reference to the accompanying drawings. However, the use of the technical solutions of the present application is not limited to the various applications mentioned in the embodiments of the present application. Various structures and variations can be easily implemented with reference to the technical solutions of the present application to achieve the various beneficial effects mentioned in this article. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes made without departing from the purpose of the present application shall fall within the scope covered by the patent of the present application.

Claims

1. A common-aperture and common-field-of-view full-band image-space scanning hyperspectral imaging system, the system comprising a first primary mirror (1), an out-of-field stray light diaphragm (2), a secondary mirror (3), an image-space scanning mirror (4), a turning mirror (5), a front dichroic filter, an imaging system, a rear dichroic filter, and a spectrometer, characterized in that, The off-axis stray light stop (2) is located at the intermediate image plane formed by the first primary mirror (1) and the secondary mirror (3); the image-side scanning mirror (4) is located at the exit pupil plane formed by the first primary mirror (1) and the secondary mirror (3); the front dichroic filter includes a first dichroic filter (6-1), a second dichroic filter (6-2), and a third dichroic filter (6-3); the first dichroic filter (6-1) reflects ultraviolet-visible light and transmits infrared light, the second dichroic filter (6-2) reflects near-infrared-shortwave infrared light and transmits mid-wave-very long wave infrared light, the third dichroic filter (6-3) reflects mid-wave-long wave infrared light and transmits long wave-very long wave infrared light; the first dichroic filter (6-1), the second dichroic filter (6-2), and the third dichroic filter (6-3) are all located in the common field of view collimated optical path formed by the first primary mirror (1) and the secondary mirror (3); the imaging system includes a first imaging system (7-1), a second imaging system (7-2), a third imaging system (7-3), and a fourth imaging system (7-4); the rear dichroic filter includes a fourth dichroic filter (8-1), a fifth dichroic filter (8-2), a sixth dichroic filter (8-3), and a seventh dichroic filter (8-4); the fourth dichroic filter (8-1) reflects ultraviolet light and transmits visible light, the fifth dichroic filter (8-2) reflects near-infrared light and transmits shortwave infrared light, the sixth dichroic filter (8-3) reflects mid-wave infrared light and transmits long wave infrared first-band light, the seventh dichroic filter (8-4) reflects long wave infrared second-band light and transmits very long wave infrared light; Light rays from the object side are converged by the first primary mirror (1) to the off-axis stray light stop (2), then collimated by the secondary mirror (3) and the pupil is reduced, and then reflected by the image-side scanning mirror (4) and the turning mirror (5) to the front dichroic filter, and sequentially pass through the first dichroic filter (6-1), the second dichroic filter (6-2), and the third dichroic filter (6-3) to form four optical channels of ultraviolet-visible light, near-infrared-shortwave infrared light, mid-wave-long wave infrared light, and long wave-very long wave infrared light; The ultraviolet light - visible light is converged and imaged by the first imaging system (7 - 1), and then forms two optical channels of ultraviolet light and visible light through the fourth dichroic filter (8 - 1); the near - infrared - short - wave infrared light is converged and imaged by the second imaging system (7 - 2), and then forms two optical channels of near - infrared light and short - wave infrared light through the fifth dichroic filter (8 - 2); the mid - wave - long - wave infrared light is converged and imaged by the third imaging system (7 - 3), and then forms two optical channels of mid - wave infrared light and long - wave infrared first - band light through the sixth dichroic filter (8 - 3); the long - wave - very - long - wave infrared light is converged and imaged by the fourth imaging system (7 - 4), and then forms two optical channels of long - wave infrared second - band light and very - long - wave infrared light through the seventh dichroic filter (8 - 4); in this way, the four optical channels in the full - band are further divided into eight channels, forming eight independent imaging common - field focal planes, which are docked with the eight spectrometers to form a hyper - spectral imaging system with common aperture, common field of view, and full - band image - side scanning.

2. The all-band image-plane scanning hyperspectral imaging system with a common aperture and a common field of view according to claim 1, wherein The system further includes a rear catadioptric mirror (10), and the long - wave - very - long - wave infrared light enters the fourth imaging system (7 - 4) after the optical path is refracted by the rear catadioptric mirror (10).

3. A common-aperture, common-field-of-view, full-band image-space scanning hyperspectral imaging system according to claim 1, characterized in that, The first primary mirror (1) and the secondary mirror (3) are off - axis parabolic mirrors with a rotational paraboloid shape.

4. A common-aperture and common-field-of-view full-band image-plane scanning hyperspectral imaging system according to claim 1, wherein The rotation axis of the image - side scanning mirror (4) is perpendicular to the meridian plane and coincides with the exit pupil plane formed by the first primary mirror (1) and the secondary mirror (3). By rotating the image - side scanning mirror (4), the field of view of the telescope system composed of the first primary mirror (1) and the secondary mirror (3) can be changed, and the variable field of view in the object space can be converted into a fixed field of view in the image space.

5. A common-aperture and common-field-of-view full-band image-plane scanning hyperspectral imaging system according to claim 1 or 4, characterized in that, The size of the image - side scanning mirror (4) is less than or equal to 1 / 10 of the size of the first primary mirror (1).

6. The all-band image-side scanning hyperspectral imaging system with a common aperture and a common field of view according to claim 1, characterized in that The material of the front dichroic filter is zinc selenide; the first dichroic filter (6 - 1) can achieve high reflection in the ultraviolet - visible light band and high transmission in the near - infrared - very - long - wave infrared light band; the second dichroic filter (6 - 2) can achieve high reflection in the near - short - wave infrared light band and high transmission in the mid - wave - very - long - wave infrared light band; the third dichroic filter (6 - 3) can achieve high reflection in the mid - wave - long - wave infrared light and high transmission in the long - wave - very - long - wave infrared light band.

7. A common-aperture and common-field-of-view full-band image-space scanning hyperspectral imaging system according to claim 1, characterized in that, The material of the rear dichroic filter is fused quartz and zinc selenide. The fourth dichroic filter (8 - 1) can achieve high reflection in the ultraviolet light band and high transmission in the visible light band; the fifth dichroic filter (8 - 2) can achieve high reflection in the near - infrared light band and high transmission in the short - wave infrared light band; the sixth dichroic filter (8 - 3) can achieve high reflection in the mid - wave infrared light band and high transmission in the long - wave infrared first - band light; the seventh dichroic filter (8 - 4) can achieve high reflection in the long - wave infrared second - band light and high transmission in the very - long - wave infrared light band.

8. A common-aperture, common-field-of-view, full-band image-plane scanning hyperspectral imaging system according to claim 1 or 6 or 7, characterized in that, The wavelength range of the ultraviolet light is 0.2 μm to 0.4 μm; the visible light wavelength range is 0.4 μm to 0.75 μm; the near-infrared light wavelength range is 0.75 μm to 1.4 μm; the short-wave infrared light wavelength range is 1.4 μm to 2.7 μm; the mid-wave infrared light wavelength range is 2.7 μm to 5.0 μm; the long-wave infrared first wavelength range is 5.0 μm to 9.0 μm; the long-wave infrared second wavelength range is 9.0 μm to 12.5 μm; the very long-wave infrared light wavelength range is 12.5 μm to 16 μm.

9. The all-wave image-side scanning hyperspectral imaging system with a common aperture and a common field of view according to claim 1, characterized in that, The imaging systems are all off-axis three-reflection imaging modules. The first imaging system (7-1), the second imaging system (7-2), the third imaging system (7-3), and the fourth imaging system (7-4) are all modularly designed and have the same mirror parameters.

10. A common-aperture, common-field-of-view, full-band image-space scanning hyperspectral imaging system according to claim 1 or 2, characterized in that, The spectroscopic layout module (0) composed of the front dichroic filter, the imaging system, the rear dichroic filter, the spectrometer, and the rear catadioptric mirror (10) rotates 90° as a whole along the Z-axis, which can reduce the volume of the hyperspectral imaging system.

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