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摘要:为了对作物进行更灵敏、更高效的生长监测，国内外相继设计了各类高光谱分辨率的光谱仪用来探测叶绿素荧光效率。本文对传统Offner光谱仪系统进行改进，得到了光谱分辨率更高的整体结构。光学系统选用双反望远系统，光谱仪部分采用高刻线密度反射型凸面光栅，实现更高的光谱分辨率。在此基础上，添加放大透镜以满足长狭缝需求，同时得到了一种狭缝-像面在光栅同一侧的Offner结构。利用codeV软件对望远系统和光谱仪部分的初始结构进行优化。结果表明，工作在670~780 nm波段时，光谱分辨率为0.3 nm，在17 lp/mm截止频率下整体调制传递函数MTF>0.75，各视场条件下弥散斑均方根半径RMS<15 μm。由此可知，该方法可以满足作物生长叶绿素监测领域的高精度、实时性要求。
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关键词:
- 光学设计/
- Offner光谱成像系统/
- 超高光谱分辨率
Abstract:To monitor crop growth more efficiently, various kinds of hyperspectral spectrometers have been designed to detect chlorophyll fluorescence. In this paper, the traditional Offner spectrometer system is improved, and a structure with a higher spectral resolution is obtained. The double-reflection telescope system is selected, and the spectrometer adopts a highly dense linear reflective convex grating to achieve higher spectral resolution. On this basis, an amplifying lens is added to meet the need for a long slit. An Offner structure is obtained with a slit and image plane on the same side of the grating. The initial structure of the telescope system and the spectrometer are optimized by codeV software. The results show that the spectral resolution is 0.3 nm in the range of 670~780 nm, the overall Modulation Transfer Function (MTF) is greater than 0.75 at the cut-off frequency of 17 lp/mm, and the Root Mean Square radius (RMS) of the speckle is less than 15 μm. The proposed system can meet the requirements of highly precise real-time monitoring in crop growth chlorophyll detection. -
图 12各波段整体结构MTF曲线图
Figure 12.MTF curves of the system at different wavelengths (λ=670、725、780 nm)
图 13各波段整体结构RMS点列图
Figure 13.RMS point diagrams of the system at different wavelengths (λ=670、725、780 nm)
图 14整体结构径向能量分布图
Figure 14.Radial energy distributions of the system at different wavelengths (λ=670、725、780 nm)
表 1超高光谱分辨率改进型Offner光谱仪各项指标
Table 1.Indexes of an improved Offner spectrometer with ultra high spectral resolution
项目 指标 探测高度/km 810 光谱分辨率/nm 0.3 工作波长/nm 670~780 焦距/mm 240 入瞳直径/mm 75 半视场(°) x：4，y：20 调制传函（MTF） >0.75 (17 lp/mm) 弥散斑均方根半径（RMS）/μm <15 
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表 2GSENSE4040BSI探测器指标
Table 2.Detector parameters of GSENSE4040BSI
项目 参数 分辨率 4096×4096 像元尺寸/μm 9×9 感光面积/mm 36.8×36.8 照明方式 背照明 帧频(frame·s−1) 24 下载:
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[1] 杨卫梅, 刘刚, 欧全宏, 等. 红外光谱结合曲线拟合对自然老化豆类种子的研究[J]. 分析化学,2019,47(12):2004-2016.YANG W M, LIU G, OU Q H,et al. Study on natural aging legume seeds by infrared spectroscopy combined with curve fitting[J].Chinese Journal of Analytical Chemistry, 2019, 47(12): 2004-2016. (in Chinese) [2] 刘亚超, 李永玉, 彭彦昆, 等. 红外漫透射光补偿法无损快速检测大米直链淀粉[J]. 分析化学,2019,47(5):785-793.LIU Y C, LI Y Y, PENG Y K,et al. Non-destructive rapid detection of rice amylose content by near-infrared diffuse transmission optical compensation method[J].Chinese Journal of Analytical Chemistry, 2019, 47(5): 785-793. (in Chinese) [3] 马文强, 张漫, 李源, 等. 基于高光谱成像的核桃仁品质检测与分类方法[J]. 分析化学,2020,48(12):1737-1746.MA W Q, ZHANG M, LI Y,et al. Detection and grading method of walnut kernel quality based on hyperspectral image[J].Chinese Journal of Analytical Chemistry, 2020, 48(12): 1737-1746. (in Chinese) [4] 王恒. 应用于植物生理检测的高通量叶绿素荧光成像系统研究[D]. 杭州: 浙江大学, 2018.WANG H. Research on high throughput chlorophyll fluorescence imaging system applied in plant physiology detection[D]. Hangzhou: Zhejiang University, 2018. [5] TOPPING M Q, PFEIFFER J E, SPARKS A W,et al. Advanced airborne hyperspectral imaging system (AAHIS)[J].Proceedings of SPIE, 2002, 4816: 1-11.doi:10.1117/12.453794 [6] COPPO P, PETTINATO L, NUZZI D,et al. Instrument predevelopment activities for FLEX mission[J].Optical Engineering, 2019, 58(7): 075102. [7] 付严宇, 杨桄, 关世豪. 航空航天高光谱成像仪研究现状及发展趋势[J]. 红外,2020,41(8):1-8, 14.doi:10.3969/j.issn.1672-8785.2020.08.001FU Y Y, YANG G, GUAN SH H. Research status and development trend of hyperspectral imagers onboard airborne and spaceborne platforms[J].Infrared, 2020, 41(8): 1-8, 14. (in Chinese)doi:10.3969/j.issn.1672-8785.2020.08.001 [8] 刘玉娟, 崔继承, 巴音贺希格, 等. 凸面光栅成像光谱仪的研制与应用[J]. 光学 精密工程,2012,20(1):52-57.doi:10.3788/OPE.20122001.0052LIU Y J, CUI J CH, BAYANHESHIG,et al. Design and application of imaging spectro meter with convex grating[J].Optics and Precision Engineering, 2012, 20(1): 52-57. (in Chinese)doi:10.3788/OPE.20122001.0052 [9] 朱雨霁, 尹达一, 陈永和, 等. 高光谱分辨率紫外Offner成像光谱仪系统设计[J]. 光学学报,2018,38(2):0222001.doi:10.3788/AOS201838.0222001ZHU Y J, YIN D Y, CHEN Y H,et al. Design of hyperspectral resolution ultraviolet Offner imaging spectrometer system[J].Acta Optica Sinica, 2018, 38(2): 0222001. (in Chinese)doi:10.3788/AOS201838.0222001 [10] 朱嘉诚, 沈为民. 紧凑型消像散长狭缝光谱仪光学系统[J]. 红外与毫米波学报,2019,38(4):542-548.doi:10.11972/j.issn.1001-9014.2019.04.022ZHU J CH, SHEN W M. Compact anastigmatic long-slit spectrometer[J].Journal of Infrared and Millimeter Waves, 2019, 38(4): 542-548. (in Chinese)doi:10.11972/j.issn.1001-9014.2019.04.022 [11] 徐达, 张国玉, 孙高飞. 改进Offner型凸面光栅光谱辐射定标光学系统设计[J]. 光学学报,2020,40(8):0822002.doi:10.3788/AOS202040.0822002XU D, ZHANG G Y, SUN G F. Design of advanced Offner-type convex grating spectral radiation calibration optical system[J].Acta Optica Sinica, 2020, 40(8): 0822002. (in Chinese)doi:10.3788/AOS202040.0822002 [12] 周正平, 赵知诚, 靳阳明, 等. 大相对孔径宽视场无遮拦平场两反射镜望远物镜分析与设计[J]. 光学学报,2015,35(3):0322002.doi:10.3788/AOS201535.0322002ZHOU ZH P, ZHAO ZH CH, JIN Y M,et al. Analysis and design of unobscured flat-field two-mirror telescopic objective with wide field of view and large relative aperture[J].Acta Optica Sinica, 2015, 35(3): 0322002. (in Chinese)doi:10.3788/AOS201535.0322002 [13] 杨拓拓, 陈新华, 赵知诚, 等. Offner分光成像系统的球面自准直法快速装调[J]. 中国光学,2020,13(6):1324-1331.doi:10.37188/CO.2020-0058YANG T T, CHEN X H, ZHAO ZH CH,et al. Fast alignment of an offner imaging spectrometer using a spherical autostigmatic method[J].Chinese Optics, 2020, 13(6): 1324-1331. (in Chinese)doi:10.37188/CO.2020-0058 [14] 兰卫华, 王欣, 刘银年, 等. 凸面光栅的衍射效率计算及其二级光谱抑制[J]. 红外技术,2009,31(5):256-258.doi:10.3969/j.issn.1001-8891.2009.05.003LAN W H, WANG X, LIU Y N,et al. The convex grating diffractive efficiency calculating and second diffraction suppression[J].Infrared Technology, 2009, 31(5): 256-258. (in Chinese)doi:10.3969/j.issn.1001-8891.2009.05.003 [15] 徐达, 岳世新, 张国玉, 等. Offner型凸面光栅宽动态范围辐射定标光源设计[J]. 中国光学,2020,13(5):1085-1093.doi:10.37188/CO.2019-0221XU D, YUE SH X, ZHANG G Y,et al. Design of an Offner convex grating radiation calibration light source with a wide dynamic range[J].Chinese Optics, 2020, 13(5): 1085-1093. (in Chinese)doi:10.37188/CO.2019-0221 [16] 陈醒, 胡春晖, 颜昌翔, 等. 大视场空间可见光相机的杂散光分析与抑制[J]. 中国光学,2019,12(3):678-685.doi:10.3788/co.20191203.0678CHEN X, HU CH H, YAN CH X,et al. Analysis and suppression of space stray light of visible cameras with wide field of view[J].Chinese Optics, 2019, 12(3): 678-685. (in Chinese)doi:10.3788/co.20191203.0678 -
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