Small-F-number imaging spectrum system

Abstract

The invention discloses a small-F-number imaging spectrum system, and relates to the technical field of imaging spectrums, and the system comprises a front telescoping system, a slit system, a collimation system, a light splitting system, an imaging system and a detector which are arranged in sequence. The front telescope system comprises a plurality of spherical lenses which are arranged in sequence and form an image space telecentric optical path structure; the slit system comprises a parallel flat plate; the collimation system comprises a plurality of spherical lenses which are arranged in sequence; the light splitting system is of a prism-grating-prism combined structure; the imaging system comprises a plurality of spherical lenses which are arranged in sequence; the detector is used for imaging display according to the light beams focused by the imaging system. The method has the characteristic of small F number, and the detail distinguishing capability of an imaging spectrum system can be improved.

Description

Technical Field

[0001] The present application relates to the field of imaging spectroscopy technology, and particularly to a small F-number imaging spectroscopy system. Background Art

[0002] The push-broom imaging spectroscopy system is an efficient data acquisition tool. By spatially scanning the target, it can not only obtain the spatial information of the target but also acquire its spectral information. This technology combines the advantages of imaging and spectral analysis, showing broad application value and prospects in multiple fields, such as land resource survey, monitoring of crop growth and pest control, and medical applications. With the continuous progress of technology, the application scope of this system will continue to expand, helping to address global environmental and resource challenges.

[0003] Currently, the F-number (focal length / entrance pupil diameter) of the push-broom imaging spectroscopy system is generally greater than 2. When the focal length of the front telescopic system is fixed, the larger the F-number, the fewer the light rays of the target object entering the optical system, which will lead to a decrease in the light flux in the optical system, and further result in a poor ability to resolve the details of the target object and a relatively low overall brightness. Summary of the Invention

[0004] The purpose of the present application is to provide a small F-number imaging spectroscopy system, which can improve the ability of the imaging spectroscopy system to resolve details.

[0005] To achieve the above purpose, the present application provides the following solutions: The present application provides a small F-number imaging spectroscopy system, including a front telescopic system, a slit system, a collimating system, a spectroscopic system, an imaging system, and a detector arranged in sequence; wherein, the front telescopic system includes multiple spherical lenses arranged in sequence and forms an image-space telecentric optical path structure; the slit system includes a parallel plate; the collimating system includes multiple spherical lenses arranged in sequence; the spectroscopic system is a prism-grating-prism combination structure; the imaging system includes multiple spherical lenses arranged in sequence; the detector is used for imaging display based on the beam focused by the imaging system.

[0006] According to the specific embodiments provided by the present application, the present application has the following technical effects: The present application provides a small F-number imaging spectroscopy system, in which the front telescopic system includes multiple spherical lenses arranged in sequence and forms an image-space telecentric optical path structure. This design structure can effectively reduce the clear aperture of the collimation system and reduce the design difficulty of the collimation system. The spectroscopic system adopts a prism-grating-prism combination structure and uses it as a dispersion element, which can ensure that the optical axes of each subsystem are parallel. In addition, the slit system includes a parallel plate collimation system and the imaging system both include multiple spherical lenses arranged in sequence. Finally, the detector performs imaging display based on the beam focused by the imaging system to achieve spectral imaging. Through the above structural settings, an F-number less than 2 can be obtained, which can increase the light flux in the system, improve the signal-to-noise ratio, and better resolve target details. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0008] Figure 1 It is a schematic structural diagram of the front telescopic system in an embodiment of the present application.

[0009] Figure 2 It is a schematic structural diagram of the small F-number imaging spectroscopy system in an embodiment of the present application.

[0010] Figure 3 It is an optical transfer function diagram of the small F-number imaging spectroscopy system of the present application at 450 nm.

[0011] Figure 4 It is an optical transfer function diagram of the small F-number imaging spectroscopy system of the present application at 700 nm.

[0012] Figure 5 It is a relative illuminance diagram of the small F-number imaging spectroscopy system of the present application at the central wavelength.

[0013] Reference numerals: 1 - first spherical lens, 2 - second spherical lens, 3 - third spherical lens, 4 - fourth spherical lens, 5 - fifth spherical lens, 6 - sixth spherical lens, 7 - seventh spherical lens, 8 - eighth spherical lens, 9 - ninth spherical lens, 10 - tenth spherical lens, 11 - eleventh spherical lens, 12 - twelfth spherical lens, 13 - thirteenth spherical lens, 14 - fourteenth spherical lens, 15 - fifteenth spherical lens, 16 - sixteenth spherical lens, 17 - seventeenth spherical lens, 18 - eighteenth spherical lens, 19 - nineteenth spherical lens, 20 - parallel plate, 21 - first prism, 22 - transmissive grating, 23 - second prism. Detailed implementation manners

[0014] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0015] To make the purpose, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0016] In an exemplary embodiment, the present application provides a small F - number imaging spectroscopic system, which includes a pre - telescopic system, a slit system, a collimating system, a spectroscopic system, an imaging system, and a detector arranged in sequence, specifically arranged in sequence along the beam propagation direction.

[0017] During operation, the pre - telescopic lens images the distant target beam onto the slit system; the collimating system adjusts the beam passing through the slit system into a parallel beam and sends it to the spectroscopic system; the imaging system focuses the beam passing through the spectroscopic system onto the detector; the detector is used to perform imaging display based on the beam focused by the imaging system.

[0018] In a specific application example, the pre - telescopic system includes multiple spherical lenses arranged in sequence and forms an image - side telecentric optical path structure; the design structure of the image - side telecentric can effectively reduce the clear aperture of the collimating system and reduce the design difficulty of the collimating system. The slit system includes a parallel plate, and it is a single parallel plate 20. The collimating system includes multiple spherical lenses arranged in sequence. The spectroscopic system is a prism - grating - prism combination structure. The imaging system includes multiple spherical lenses arranged in sequence. Among them, the focal length of the pre - telescopic system ranges from 24.5 mm to 25.5 mm, the focal length of the collimating system ranges from 33 mm to 34 mm, and the focal length of the imaging system ranges from 33 mm to 34 mm.

[0019] In the above application example, due to the use of a global spherical lens for design, the processing cost is effectively reduced. In addition, by reasonably distributing the aberrations introduced in each spherical lens, the lens position distribution in the system of the present application is reasonable. The total length of the system is 192 mm (from the entrance pupil to the image plane), with a short length and a small volume, and it can work on a small unmanned aerial vehicle (UAV) platform.

[0020] The small F-number imaging spectroscopy system provided by the present application can extract spectral information from light rays in the spectral range of 450 nm - 700 nm. Specifically, the working spectral range of the system of the present application is 450 nm - 700 nm, the field of view range is -8° - +8°, the entrance pupil diameter is 13.9 mm, and the focal length of the front telescopic system is 25 mm. It can be known that the F-number of this system = entrance pupil diameter / focal length = 1.8. This design with a small F-number can increase the light flux in the system, improve the signal-to-noise ratio, and better resolve target details.

[0021] In another specific application example, as Figure 2 shown, the small F-number imaging spectroscopy system of the present application uses a total of 19 spherical lenses, one parallel plate, two prisms, and one transmissive grating. Among them, the front telescopic system is composed of 7 spherical lenses, the slit system is composed of one parallel plate, the spectroscopic system is composed of two prisms and one transmissive grating, and the collimating system and the imaging system are each composed of 6 spherical lenses.

[0022] In another specific application example, as Figure 1 shown, the front telescopic system includes seven spherical lenses, which are in sequence: the first spherical lens 1, the second spherical lens 2, the third spherical lens 3, the fourth spherical lens 4, the fifth spherical lens 5, the sixth spherical lens 6, and the seventh spherical lens 7, and are specifically arranged in sequence along the light propagation direction.

[0023] The first spherical lens 1 is a biconvex lens. The numerical range of the focal length f1 of the first spherical lens 1 is: 1.2 mm < f1 < 1.3 mm. The numerical range of the thickness h1 of the first spherical lens is: 5.1 mm < h1 < 5.3 mm. The second spherical lens 2 is a biconcave lens. The numerical range of the focal length f2 of the second spherical lens 2 is: -21 mm < f2 < -20 mm. The numerical range of the thickness h2 of the second spherical lens 2 is: 2 mm < h2 < 2.1 mm. The third spherical lens 3 is a biconvex lens. The numerical range of the focal length f3 of the third spherical lens 3 is: 20 mm < f3 < 21 mm. The numerical range of the thickness h3 of the third spherical lens 3 is: 5.8 mm < h3 < 6 mm. The fourth spherical lens 4 is a meniscus lens. The numerical range of the focal length f4 of the fourth spherical lens 4 is: 90 mm < f4 < 93 mm. The numerical range of the thickness h4 of the fourth spherical lens 4 is: 5.8 mm < h4 < 6 mm. The fifth spherical lens 5 is a biconcave lens. The numerical range of the focal length f5 of the fifth spherical lens 5 is: -8 mm < f5 < -7 mm. The numerical range of the thickness h5 of the fifth spherical lens 5 is: 1.5 mm < h5 < 1.7 mm. The sixth spherical lens 6 is a biconvex lens. The numerical range of the focal length f6 of the sixth spherical lens 6 is: 18 mm < f6 < 19 mm. The numerical range of the thickness h6 of the sixth spherical lens 6 is: 2.2 mm < h6 < 2.5 mm. The seventh spherical lens 7 is a meniscus lens. The numerical range of the focal length f7 of the seventh spherical lens 7 is: 24 mm < f7 < 25 mm. The numerical range of the thickness h7 of the seventh spherical lens 7 is: 2.3 mm < h7 < 2.6 mm.

[0024] In another specific application example, the collimation system includes six spherical lenses, which are, in order: the eighth spherical lens 8, the ninth spherical lens 9, the tenth spherical lens 10, the eleventh spherical lens 11, the twelfth spherical lens 12, and the thirteenth spherical lens 13, and are arranged in this order along the light propagation direction.

[0025] The eighth spherical lens 8 is a biconcave lens, and the numerical range of the focal length f8 of the eighth spherical lens 8 is: -12 mm < f8 < -11 mm, and the numerical range of the thickness h8 of the eighth spherical lens 8 is: 1.2 mm < h8 < 1.4 mm; the ninth spherical lens 9 is a meniscus lens, and the numerical range of the focal length f9 of the ninth spherical lens 9 is: 19 mm < f9 < 20 mm, and the numerical range of the thickness h9 of the ninth spherical lens 9 is: 7.9 mm < h9 < 8.2 mm; the tenth spherical lens 10 is a biconvex lens, and the numerical range of the focal length f10 of the tenth spherical lens 10 is: 26 mm < f10 < 28 mm, and the numerical range of the thickness h10 of the tenth spherical lens 10 is: 7.9 mm < h10 < 8.2 mm; the eleventh spherical lens 11 and the twelfth spherical lens 12 are combined into a doublet lens; the eleventh spherical lens 11 is a biconcave lens, and the numerical range of the focal length f11 of the eleventh spherical lens 11 is: -11 mm < f11 < -10 mm, and the numerical range of the thickness h11 of the eleventh spherical lens 11 is: 8.1 mm < h11 < 8.3 mm; the twelfth spherical lens 12 is a biconvex lens, and the numerical range of the focal length f12 of the twelfth spherical lens 12 is: 23 mm < f12 < 26 mm, and the numerical range of the thickness h12 of the twelfth spherical lens 12 is: 8 mm < h12 < 8.3 mm. The thirteenth spherical lens 13 is a meniscus lens, and the numerical range of the focal length f13 of the thirteenth spherical lens 13 is: 60 mm < f13 < 65 mm, and the numerical range of the thickness h13 of the thirteenth spherical lens 13 is: 8 mm < h13 < 8.3 mm.

[0026] In another specific application example, the spectroscopic system includes a first prism 21, a transmissive grating 22, and a second prism 23 arranged in sequence, and they are arranged in order along the light propagation direction; the first prism 21 and the second prism 23 have the same structural parameters, and the apex angles of both are 8.614°, and the central thicknesses of the first prism 21 and the second prism 23 are both 4 mm. The grating density of the transmissive grating 22 is 300 lines / mm. In addition, the materials of the first prism 21, the transmissive grating 22, and the second prism 23 are all H-BAK7. By using the prism-grating-prism combination as the dispersion element, it is ensured that the optical axes of each subsystem are parallel.

[0027] In another specific application example, the imaging system includes six spherical lenses, which are: the fourteenth spherical lens 14, the fifteenth spherical lens 15, the sixteenth spherical lens 16, the seventeenth spherical lens 17, the eighteenth spherical lens 18, and the nineteenth spherical lens 19, and they are arranged in order along the light propagation direction.

[0028] The fourteenth spherical lens 14 is a biconvex lens. The numerical range of the focal length f14 of the fourteenth spherical lens 14 is: 80 mm < f14 < 86 mm. The numerical range of the thickness h14 of the fourteenth spherical lens 14 is: 3.9 mm < h14 < 4 mm. The fifteenth spherical lens 15 and the sixteenth spherical lens 16 are cemented doublets. The fifteenth lens 15 is a biconvex lens. The numerical range of the focal length f15 of the fifteenth lens 15 is: 25 mm < f15 < 27 mm. The numerical range of the thickness h15 of the fifteenth lens 15 is: 6.8 mm < h15 < 7 mm. The sixteenth lens 16 is a biconcave lens. The numerical range of the focal length f16 of the sixteenth lens 16 is: -13 mm < f16 < -11 mm. The numerical range of the thickness h16 of the sixteenth lens 16 is: 7.4 mm < h16 < 7.5 mm. The seventeenth spherical lens 17 is a biconvex lens. The numerical range of the focal length f17 of the seventeenth spherical lens 17 is: 30 mm < f17 < 32 mm. The numerical range of the thickness h17 of the seventeenth spherical lens 17 is: 7.8 mm < h17 < 8.1 mm. The eighteenth spherical lens 18 is a biconvex lens. The numerical range of the focal length f18 of the eighteenth spherical lens 18 is: 28 mm < f18 < 29 mm. The numerical range of the thickness h18 of the eighteenth spherical lens 18 is: 7.8 mm < h18 < 8.1 mm. The nineteenth spherical lens 19 is a biconcave lens. The numerical range of the focal length f19 of the nineteenth spherical lens 19 is: -23 mm < f19 < -22 mm. The numerical range of the thickness h19 of the nineteenth spherical lens 19 is: 7.9 mm < h19 < 8.2 mm.

[0029] In another specific application example, the small F-number imaging spectroscopic system of the present application includes the following multiple components arranged in sequence along the light propagation direction: a first spherical lens 1 with a focal length of 1.25 mm and a thickness of 5.2 mm, a first spherical lens 2 with a focal length of -20.5 mm and a thickness of 2 mm, a third spherical lens 3 with a focal length of 20 mm and a thickness of 6 mm, a fourth spherical lens 4 with a focal length of 92 mm and a thickness of 5.8 mm, a fifth spherical lens 5 with a focal length of -7.8 mm and a thickness of 1.6 mm, a sixth spherical lens 6 with a focal length of 18 mm and a thickness of 2.4 mm, a seventh spherical lens 7 with a focal length of 24 mm and a thickness of 2.3 mm, a parallel plate 20, an eighth spherical lens 8 with a focal length of -12 mm and a thickness of 1.4 mm, a ninth spherical lens 9 with a focal length of 19 mm and a thickness of 8 mm, a tenth spherical lens 10 with a focal length of 26 mm and a thickness of 8 mm, an eleventh spherical lens 11 with a focal length of -11 mm and a thickness of 8.2 mm, a twelfth spherical lens 12 with a focal length of 25 mm and a thickness of 8.2 mm, a thirteenth spherical lens 13 with a focal length of 62 mm and a thickness of 8.2 mm, a first prism 21, a transmissive grating 22, a second prism 23, a fourteenth spherical lens 14 with a focal length of 85 mm and a thickness of 3.9 mm, a fifteenth spherical lens 15 with a focal length of 26 mm and a thickness of 6. mm, a sixteenth spherical lens 16 with a focal length of -12 mm and a thickness of 7.4 mm, a seventeenth spherical lens 17 with a focal length of 30 mm and a thickness of 8 mm, an eighteenth spherical lens 18 with a focal length of 28 mm and a thickness of 7.8 mm, and a nineteenth spherical lens 19 with a focal length of -23 mm and a thickness of 8.1 mm.

[0030] As Figure 3 and Figure 4 shown, the optical transfer function diagrams of the small F-number imaging spectroscopic system of the present application at 450 nm and 700 nm are presented. In these two diagrams, the optical function curves corresponding to the on-axis field of view, 4° semi-field of view, and 8° semi-field of view are given. By comparing Figure 3 and Figure 4 it can be seen that the value of the optical transfer function of the small F-number imaging spectroscopic system of the present application at 72.5 lp / mm is basically greater than 0.5, indicating that the small F-number imaging spectroscopic system of the present application can better transfer the target details.

[0031] As Figure 5 shown, the relative illuminance diagram of the small F-number imaging spectroscopic system of the present application at the central wavelength is presented. Among them, the relative illuminance refers to the ratio of the illuminance at different coordinate points on the image plane to the illuminance at the center point. From Figure 5 it can be seen that the relative illuminance of the small F-number imaging spectroscopic system of the present application at the central wavelength is greater than 0.8, indicating that there will be no obvious vignetting at the edge of the image plane.

[0032] In summary, the small F-number imaging spectroscopy system of the present application can be used as a pushbroom imaging spectroscopy system. To meet the requirement of high spectral resolution, the F-number of the imaging spectroscopy system is reduced, which increases the optical flux in the optical system and obtains a higher signal-to-noise ratio.

[0033] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0034] Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A small F-number imaging spectroscopy system, characterized in that: The small F-number imaging spectroscopic system includes a front telescopic system, a slit system, a collimating system, a spectroscopic system, an imaging system, and a detector arranged in sequence; Among them, the front telescopic system includes multiple spherical lenses arranged in sequence and forms an image-space telecentric optical path structure; the slit system includes a parallel plate; the collimating system includes multiple spherical lenses arranged in sequence; the spectroscopic system is a prism-grating-prism combination structure; the imaging system includes multiple spherical lenses arranged in sequence; the detector is used for imaging and displaying according to the light beam focused by the imaging system.

2. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The working spectral range of the small F-number imaging spectroscopic system is 450nm - 700nm, the field of view angle range is -8° - +8°, the entrance pupil diameter is 13.9mm, and the F-number is 1.

8.

3. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The focal length range of the front telescopic system is 24.5mm - 25.5mm, the focal length range of the collimating system is 33mm - 34mm, and the focal length range of the imaging system is 33mm - 34mm.

4. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The front telescopic system includes seven spherical lenses, which are: the first spherical lens, the second spherical lens, the third spherical lens, the fourth spherical lens, the fifth spherical lens, the sixth spherical lens, and the seventh spherical lens; The first spherical lens is a biconvex lens, and the numerical range of the focal length f1 of the first spherical lens is: 1.2mm < f1 < 1.3mm, and the numerical range of the thickness h1 of the first spherical lens is: 5.1mm < h1 < 5.3mm; The second spherical lens is a biconcave lens, and the numerical range of the focal length f2 of the second spherical lens is: -21mm < f2 < -20mm, and the numerical range of the thickness h2 of the second spherical lens is: 2mm < h2 < 2.1mm; The third spherical lens is a biconvex lens, and the numerical range of the focal length f3 of the third spherical lens is: 20mm < f3 < 21mm, and the numerical range of the thickness h3 of the third spherical lens is: 5.8mm < h3 < 6mm; The fourth spherical lens is a meniscus lens, and the numerical range of the focal length f4 of the fourth spherical lens is: 90mm < f4 < 93mm, and the numerical range of the thickness h4 of the fourth spherical lens is: 5.8mm < h4 < 6mm; The fifth spherical lens is a biconcave lens, and the numerical range of the focal length f5 of the fifth spherical lens is: -8mm < f5 < -7mm, and the numerical range of the thickness h5 of the fifth spherical lens is: 1.5mm < h5 < 1.7mm; The sixth spherical lens is a biconvex lens, and the numerical range of the focal length f6 of the sixth spherical lens is: 18mm < f6 < 19mm, and the numerical range of the thickness h6 of the sixth spherical lens is: 2.2mm < h6 < 2.5mm; The seventh spherical lens is a meniscus lens, and the numerical range of the focal length f7 of the seventh spherical lens is: 24mm < f7 < 25mm, and the numerical range of the thickness h7 of the seventh spherical lens is: 2.3mm < h7 < 2.6mm.

5. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The slit system includes a parallel plate.

6. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The collimating system includes six spherical lenses, which are, in sequence: the eighth spherical lens, the ninth spherical lens, the tenth spherical lens, the eleventh spherical lens, the twelfth spherical lens, and the thirteenth spherical lens; The eighth spherical lens is a biconcave lens. The numerical range of the focal length f8 of the eighth spherical lens is: -12 mm < f8 < -11 mm. The numerical range of the thickness h8 of the eighth spherical lens is: 1.2 mm < h8 < 1.4 mm; The ninth spherical lens is a meniscus lens. The numerical range of the focal length f9 of the ninth spherical lens is: 19 mm < f9 < 20 mm. The numerical range of the thickness h9 of the ninth spherical lens is: 7.9 mm < h9 < 8.2 mm; The tenth spherical lens is a biconvex lens. The numerical range of the focal length f10 of the tenth spherical lens is: 26 mm < f10 < 28 mm. The numerical range of the thickness h10 of the tenth spherical lens is: 7.9 mm < h10 < 8.2 mm; The eleventh spherical lens and the twelfth spherical lens are combined into a doublet lens; The thirteenth spherical lens is a meniscus lens. The numerical range of the focal length f13 of the thirteenth spherical lens is: 60 mm < f13 < 65 mm. The numerical range of the thickness h13 of the thirteenth spherical lens is: 8 mm < h13 < 8.3 mm.

7. The small F-number imaging spectroscopy system according to claim 6, characterized in that: The eleventh spherical lens is a biconcave lens. The numerical range of the focal length f11 of the eleventh spherical lens is: -11 mm < f11 < -10 mm. The numerical range of the thickness h11 of the eleventh spherical lens is: 8.1 mm < h11 < 8.3 mm; The twelfth spherical lens is a biconvex lens. The numerical range of the focal length f12 of the twelfth spherical lens is: 23 mm < f12 < 26 mm. The numerical range of the thickness h12 of the twelfth spherical lens is: 8 mm < h12 < 8.3 mm.

8. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The beam splitting system includes a first prism, a transmissive grating, and a second prism arranged in sequence; the apex angles of the first prism and the second prism are both 8.614°, and the central thicknesses of the first prism and the second prism are both 4 mm; The ruling density of the transmissive grating is 300 lines / mm.

9. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The imaging system includes six spherical lenses, which are, in sequence: the fourteenth spherical lens, the fifteenth spherical lens, the sixteenth spherical lens, the seventeenth spherical lens, the eighteenth spherical lens, and the nineteenth spherical lens; The fourteenth spherical lens is a biconvex lens. The numerical range of the focal length f14 of the fourteenth spherical lens is: 80 mm < f14 < 86 mm. The numerical range of the thickness h14 of the fourteenth spherical lens is: 3.9 mm < h14 < 4 mm; The fifteenth spherical lens and the sixteenth spherical lens are a doublet lens; The seventeenth spherical lens is a biconvex lens. The numerical range of the focal length f17 of the seventeenth spherical lens is: 30 mm < f17 < 32 mm. The numerical range of the thickness h17 of the seventeenth spherical lens is: 7.8 mm < h17 < 8.1 mm; The eighteenth spherical lens is a biconvex lens. The numerical range of the focal length f18 of the eighteenth spherical lens is: 28 mm < f18 < 29 mm. The numerical range of the thickness h18 of the eighteenth spherical lens is: 7.8 mm < h18 < 8.1 mm; The nineteenth spherical lens is a biconcave lens. The numerical range of the focal length f19 of the nineteenth spherical lens is: -23 mm < f19 < -22 mm. The numerical range of the thickness h19 of the nineteenth spherical lens is: 7.9 mm < h19 < 8.2 mm.

10. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The small F-number imaging spectroscopic system operates on a small unmanned aerial vehicle (UAV) platform.

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