A small F-number imaging spectroscopy system

Abstract

This application discloses a low-F-number imaging spectroscopy system, which relates to the field of imaging spectroscopy technology. The system includes a pre-telescope system, a slit system, a collimator system, a spectroscopic system, an imaging system, and a detector, which are arranged in sequence. The pre-telescope system includes multiple spherical lenses arranged in sequence to form an image-side telecentric optical path structure; the slit system includes parallel plates; the collimator 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; and the detector is used to generate images based on the light beam focused by the imaging system. This application has the characteristics of a low F-number, which can improve the imaging spectroscopy system's ability to resolve details.

Description

Technical Field

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

[0002] A push-broom imaging spectroscopy system is a highly efficient data acquisition tool that scans a target spatially, acquiring both spatial and spectral information. This technology combines the advantages of imaging and spectral analysis, demonstrating broad application value and promise in a variety of fields, including land resource surveys, crop growth monitoring, pest and disease control, and medical applications. With continued technological advancements, 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 push-broom imaging spectroscopy systems is generally greater than 2. When the focal length of the front telescope system is fixed, the larger the F-number, the less light from the target object enters the optical system, which leads to a decrease in the optical flux, which in turn reduces the ability to resolve target object details and reduces the overall brightness. Summary of the Invention

[0004] The purpose of this 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 objectives, this application provides the following solutions:

[0006] The present application provides a small F-number imaging spectroscopy system, comprising a front telescope system, a slit system, a collimation system, a spectroscopic system, an imaging system and a detector arranged in sequence; wherein the front telescope system comprises a plurality of spherical lenses arranged in sequence, forming an image-side telecentric optical path structure; the slit system comprises a parallel plate; the collimation system comprises a plurality of spherical lenses arranged in sequence; the spectroscopic system is a prism-grating-prism combination structure; the imaging system comprises a plurality of spherical lenses arranged in sequence; and the detector is used to perform imaging display based on the light beam focused by the imaging system.

[0007] According to the specific embodiments provided in the present application, the present application has the following technical effects: The present application provides a small F-number imaging spectral system, wherein the front telescope system includes a plurality of spherical lenses arranged in sequence, and constitutes an image-side telecentric optical path structure. This design structure can effectively reduce the aperture of the collimation system and reduce the design difficulty of the collimation system. The spectroscopic system adopts a prism-grating-prism combination structure, which is used as a dispersion element to ensure that the optical axes of each subsystem remain parallel. In addition, the slit system includes a parallel plate collimation system and the imaging system includes a plurality of spherical lenses arranged in sequence. Finally, the detector performs imaging display based on the light beam focused by the imaging system to achieve spectral imaging. Through the above-mentioned structural setting, an F-number less than 2 can be obtained, which can increase the luminous flux in the system, improve the signal-to-noise ratio, and better distinguish target details. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0009] Figure 1 Schematic diagram of the structure of the front telescopic system in one embodiment of the present application.

[0010] Figure 2 Schematic diagram of the structure of a small F-number imaging spectroscopy system in one embodiment of the present application.

[0011] Figure 3 This is the optical transfer function diagram of the small F-number imaging spectroscopy system of this application at 450nm.

[0012] Figure 4 This is the optical transfer function diagram of the small F-number imaging spectroscopy system of this application at 700nm.

[0013] Figure 5 This is the relative illumination diagram of the small F-number imaging spectroscopy system of this application at the central wavelength.

[0014] Figure 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-transmission grating, 23-second prism. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0016] In order to make the purpose, features and advantages of this application more obvious and easy to understand, this application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0017] In an exemplary embodiment, the present application provides a small F-number imaging spectroscopy system, comprising a front telescope system, a slit system, a collimation system, a spectroscopic system, an imaging system and a detector arranged in sequence, specifically arranged in sequence along the propagation direction of the light beam.

[0018] During operation, the front telescopic lens images the distant target light beam onto the slit system; the collimation system adjusts the light beam passing through the slit system into a parallel light beam and sends it to the spectroscopic system; the imaging system focuses the light beam passing through the spectroscopic system onto the detector; the detector is used to perform imaging display based on the light beam focused by the imaging system.

[0019] In a specific application example, the front telescope system includes a plurality of spherical lenses arranged in sequence, and constitutes an image-side telecentric optical path structure; the image-side telecentric design structure can effectively reduce the aperture of the collimation system and reduce the design difficulty of the collimation system. The slit system includes a parallel plate 20, which is a parallel plate. The collimation system includes a plurality of spherical lenses arranged in sequence. The spectroscopic system is a prism-grating-prism combination structure. The imaging system includes a plurality of spherical lenses arranged in sequence. The focal length of the front telescope system ranges from 24.5mm to 25.5mm, the focal length of the collimation system ranges from 33mm to 34mm, and the focal length of the imaging system ranges from 33mm to 34mm.

[0020] In the above application example, the use of a spherical lens design effectively reduces processing costs. Furthermore, by rationally distributing the aberrations introduced by each spherical lens, the lens positions in the system of this application are rationally distributed. The total length of the system is 192mm (from entrance pupil to image plane), which is short and compact, making it suitable for use on small unmanned aerial vehicle platforms.

[0021] The small F-number imaging spectral system provided in the present application can extract spectral information of light within the 450nm-700nm spectral range. Specifically, the working spectrum range of the system of the present application is 450nm-700nm, the field of view angle range is -8°-+8°, the entrance pupil diameter is 13.9mm, and the focal length of the front telescope system is 25mm. It can be seen that the F-number of this system = entrance pupil diameter / focal length = 1.8. This small F-number design can increase the luminous flux in the system, improve the signal-to-noise ratio, and better distinguish target details.

[0022] In another specific application example, Figure 2 As shown, the small F-number imaging spectroscopy system of the present application uses a total of 19 spherical lenses, a parallel plate, two prisms and a transmission grating. Among them, the front telescope system is composed of 7 spherical lenses, the slit system is composed of a parallel plate, the spectroscopic system is composed of two prisms and a transmission grating, and the collimation system and imaging system are composed of 6 spherical lenses respectively.

[0023] In another specific application example, Figure 1 As shown, the front telephoto system includes seven spherical lenses, namely: first spherical lens 1, second spherical lens 2, third spherical lens 3, fourth spherical lens 4, fifth spherical lens 5, sixth spherical lens 6 and seventh spherical lens 7, which are arranged in this order along the direction of light propagation.

[0024] 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.

[0025] In another specific application example, the collimation system includes six spherical lenses, namely: 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 they are arranged in sequence along the light propagation direction.

[0026] 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.

[0027] 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 their apex angles are both 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 a prism-grating-prism combination as the dispersive element, it is ensured that the optical axes of each subsystem are parallel.

[0028] In another specific application example, the imaging system includes six spherical lenses, which are in sequence: 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.

[0029] 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 doublet lenses; 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.

[0030] In another specific application example, the small F-number imaging spectroscopy system of the present application includes the following multiple components arranged in this order along the propagation direction of light: 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 mm and a thickness of 8 mm, a tenth spherical lens 10 with a focal length of -11 mm and a thickness of 8.2 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 transmission 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.

[0031] like Figure 3 and Figure 4 As shown in the figure, the optical transfer function diagram of the small F-number imaging spectral system of this application at 450nm and 700nm respectively is given. The optical function curves corresponding to the on-axis field of view, 4° half field of view and 8° half field of view are given in these two figures. Figure 3 and Figure 4 It can be seen that the value of the optical transfer function of the small F-number imaging spectral system of the present application at 72.5 lp / mm is basically greater than 0.5, indicating that the small F-number imaging spectral system of the present application can better transmit target details.

[0032] like Figure 5 As shown in FIG, it is the relative illumination diagram of the small F number imaging spectrum system of this application at the central wavelength, wherein the relative illumination refers to the ratio of the illumination of different coordinate points on the image plane to the illumination of the central point. Figure 5 It can be seen that the relative illumination of the small F-number imaging spectral system of the present application at the central wavelength is greater than 0.8, indicating that there will be no obvious dark corners at the edge of the image plane.

[0033] In summary, the small F-number imaging spectroscopy system of the present application can be used as a push-broom imaging spectroscopy system. In order to meet the requirements of high spectral resolution, the F-number of the imaging spectroscopy system is reduced, which increases the light flux in the optical system and obtains a higher signal-to-noise ratio.

[0034] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0035] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this 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 collimation 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 flat plate; the collimation 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; 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, the second spherical lens is a biconcave lens, the third spherical lens is a biconvex lens, the fourth spherical lens is a meniscus lens, the fifth spherical lens is a biconcave lens, the sixth spherical lens is a biconvex lens, and the seventh spherical lens is a meniscus lens; The collimation system includes six spherical lenses, which are: 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 ninth spherical lens is a meniscus lens, the tenth spherical lens is a biconvex lens, the eleventh spherical lens and the twelfth spherical lens are combined into a doublet lens; the thirteenth spherical lens is a meniscus lens; The imaging system includes six spherical lenses, which are: 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 fifteenth spherical lens and the sixteenth spherical lens are doublet lenses; the seventeenth spherical lens is a biconvex lens, the eighteenth spherical lens is a biconvex lens, and the nineteenth spherical lens is a biconcave lens.

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 range of the field angle 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 range of the focal length of the front telescopic system is 24.5mm - 25.5mm, the range of the focal length of the collimation system is 33mm - 34mm, and the range of the focal length of the imaging system is 33mm - 34mm.

4. The small F-number imaging spectroscopy system according to claim 1, characterized in that: 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 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 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 numerical range of the focal length f4 of the fourth spherical lens is: 90 mm < f4 < 93 mm, and the numerical range of the thickness h4 of the fourth spherical lens is: 5.8 mm < h4 < 6 mm; The numerical range of the focal length f5 of the fifth spherical lens is: -8 mm < f5 < -7 mm, and the numerical range of the thickness h5 of the fifth spherical lens is: 1.5 mm < h5 < 1.7 mm; The numerical range of the focal length f6 of the sixth spherical lens is: 18 mm < f6 < 19 mm, and the numerical range of the thickness h6 of the sixth spherical lens is: 2.2 mm < h6 < 2.5 mm; The numerical range of the focal length f7 of the seventh spherical lens is: 24 mm < f7 < 25 mm, and the numerical range of the thickness h7 of the seventh spherical lens is: 2.3 mm < h7 < 2.6 mm.

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

6. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The numerical range of the focal length f8 of the eighth spherical lens is: -12 mm < f8 < -11 mm, and the numerical range of the thickness h8 of the eighth spherical lens is: 1.2 mm < h8 < 1.4 mm; The numerical range of the focal length f9 of the ninth spherical lens is: 19 mm < f9 < 20 mm, and the numerical range of the thickness h9 of the ninth spherical lens is: 7.9 mm < h9 < 8.2 mm; The numerical range of the focal length f10 of the tenth spherical lens is: 26 mm < f10 < 28 mm, and the numerical range of the thickness h10 of the tenth spherical lens is: 7.9 mm < h10 < 8.2 mm; The numerical range of the focal length f13 of the thirteenth spherical lens is: 60 mm < f13 < 65 mm, and 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, and 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, and 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 spectroscopic system includes a first prism, a transmission 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 transmission grating is 300 lines / mm.

9. The small F-number imaging spectroscopy system according to claim 1, characterized in that: The numerical range of the focal length f14 of the fourteenth spherical lens is: 80 mm < f14 < 86 mm, and the numerical range of the thickness h14 of the fourteenth spherical lens is: 3.9 mm < h14 < 4 mm; The numerical range of the focal length f17 of the seventeenth spherical lens is: 30 mm < f17 < 32 mm, and the numerical range of the thickness h17 of the seventeenth spherical lens is: 7.8 mm < h17 < 8.1 mm; The numerical range of the focal length f18 of the eighteenth spherical lens is: 28 mm < f18 < 29 mm, and the numerical range of the thickness h18 of the eighteenth spherical lens is: 7.8 mm < h18 < 8.1 mm; The numerical range of the focal length f19 of the nineteenth spherical lens is: -23 mm < f19 < -22 mm, and 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 platform.

Images