scholarly journals Optical Design of Imaging Spectrometer Based on Linear Variable Filter for Nighttime Light Remote Sensing

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4313
Author(s):  
Yunqiang Xie ◽  
Chunyu Liu ◽  
Shuai Liu ◽  
Xinghao Fan
Keyword(s):  
Remote Sensing ◽  
Spatial Resolution ◽  
Optical System ◽  
Optical Design ◽  
Tolerance Analysis ◽  
High Spectral Resolution ◽  
Imaging Spectrometer ◽  
Remote Sensors ◽  
Nighttime Light ◽  
Linear Variable Filter

Nighttime light remote sensing has unique advantages on reflecting human activities, and thus has been used in many fields including estimating population and GDP, analyzing light pollution and monitoring disasters and conflict. However, the existing nighttime light remote sensors have many limitations because they are subject to one or more shortcomings such as coarse spatial resolution, restricted swath width and lack of multi-spectral data. Therefore, we propose an optical system of imaging spectrometer based on linear variable filter. The imaging principle, optical specifications, optical design, imaging performance analysis and tolerance analysis are illustrated. The optical system with a focal length of 100 mm, F-number 4 and 43° field of view in the spectrum range of 400–1000 nm is presented, and excellent image quality is achieved. The system can obtain the multi-spectral images of eight bands with a spatial resolution of 21.5 m and a swath width of 320 km at the altitude of 500 km. Compared with the existing nighttime light remote sensors, our system possesses the advantages of high spatial and high spectral resolution, wide spectrum band and wide swath width simultaneously, greatly making up for the shortage of the present systems. The result of tolerance analysis shows our system satisfy the requirements of fabrication and alignment.

scholarly journals Optical Design of Improved Offner Imaging Spectrometer

2021 ◽  
Vol 2112 (1) ◽  
pp. 012007
Author(s):  
Chong Song ◽  
Yong Huang ◽  
Yangdong Yan ◽  
Dongsen Cui ◽  
Gang Wang ◽  
...  
Keyword(s):  
Optical System ◽  
Optical Design ◽  
Annular Region ◽  
Practical Application ◽  
Imaging Spectrometer ◽  
Imaging Quality ◽  
Lens Position ◽  
Operating Wavelength ◽  
The Stability ◽  
System Characteristics

Abstract An improved Offner imaging spectrometer was proposed based on the optical system characteristics of Offner imaging spectrometer, which can ensure perfect imaging quality in a wider annular region. The operating wavelength of the improved Offner imaging spectrometer ranges from 900nm to 1700nm, and the magnification is 1. Improved Offner imaging spectrometer can be obtained by changing the meniscus lens position and further optimizing the design. The results indicate that the improved Offner imaging spectrometer can effectively improve compactness and lightweight, and reduce the difficulty of optical adjustment, which is conducive to the stability of practical application.

scholarly journals Optical Design of a Shortwave Infrared Dual Camera CASSI Based on Improved Offner-Wynne Imaging Spectrometer

2021 ◽  
Vol 2112 (1) ◽  
pp. 012021
Author(s):  
Chong Song ◽  
Lipeng Huo ◽  
Yong Huang ◽  
Yangdong Yan ◽  
Gang Wang ◽  
...  
Keyword(s):  
Optical System ◽  
Imaging System ◽  
Optical Measurement ◽  
Focal Length ◽  
Optical Design ◽  
Optical Transmittance ◽  
Coded Aperture ◽  
Visual Axis ◽  
Imaging Spectrometer ◽  
Shortwave Infrared

Abstract Based on the optical system characteristics of coded aperture snapshot spectral imager (CASSI), an optimized optical system of shortwave infrared dual camera CASSI was designed based on improved Offner-Wynne imaging spectrometer. The operating wavelength of the optical system ranges from 900nm to 1700nm, and the focal length is 1200mm. It consists of two parts: the two dimensional imaging system and the multispectral CASSI imaging system. The key technical parameters of the two parts are the same and there is no visual axis difference. Therefore, the optimized optical system can effectively improve real-time performance, optical transmittance and compactness of the dual camera shortwave infrared CASSI, which is conducive to the application in optical measurement scenes in the shooting range.

Analysis and Optical Design of Very High Spectral Resolution Imaging Spectrometer of the Atmospheric CO2

2015 ◽  
Vol 35 (7) ◽  
pp. 0722001
Author(s):  
宋文宝 Song Wenbao ◽  
靳阳明 Jin Yangming ◽  
赵知诚 Zhao Zhicheng ◽  
沈为民 Shen Weimin ◽  
范东栋 Fan Dongdong
Keyword(s):  
Spectral Resolution ◽  
Optical Design ◽  
Atmospheric Co2 ◽  
High Spectral Resolution ◽  
Imaging Spectrometer ◽  
Resolution Imaging ◽  
Very High

Optical System of Far Ultraviolet Imaging Spectrometer for Space-Based Upper Atmosphere Remote Sensing

2013 ◽  
Vol 33 (1) ◽  
pp. 0122001
Author(s):  
于磊 Yu Lei ◽  
林冠宇 Lin Guanyu ◽  
于向阳 Yu Xiangyang
Keyword(s):  
Remote Sensing ◽  
Optical System ◽  
Upper Atmosphere ◽  
Imaging Spectrometer ◽  
Far Ultraviolet

scholarly journals Instrument Development: Chinese Radiometric Benchmark of Reflected Solar Band Based on Space Cryogenic Absolute Radiometer

2020 ◽  
Vol 12 (17) ◽  
pp. 2856
Author(s):  
Xin Ye ◽  
Xiaolong Yi ◽  
Chao Lin ◽  
Wei Fang ◽  
Kai Wang ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Measurement Accuracy ◽  
Signal To Noise Ratio ◽  
Imaging Spectrometer ◽  
Term Stability ◽  
Long Term Stability ◽  
Remote Sensors ◽  
Cross Calibration ◽  
Transfer Chain

Low uncertainty and long-term stability remote data are urgently needed for researching climate and meteorology variability and trends. Meeting these requirements is difficult with in-orbit calibration accuracy due to the lack of radiometric satellite benchmark. The radiometric benchmark on the reflected solar band has been under development since 2015 to overcome the on-board traceability problem of hyperspectral remote sensing satellites. This paper introduces the development progress of the Chinese radiometric benchmark of the reflected solar band based on the Space Cryogenic Absolute Radiometer (SCAR). The goal of the SCAR is to calibrate the Earth–Moon Imaging Spectrometer (EMIS) on-satellite using the benchmark transfer chain (BTC) and to transfer the traceable radiometric scale to other remote sensors via cross-calibration. The SCAR, which is an electrical substitution absolute radiometer and works at 20 K, is used to realize highly accurate radiometry with an uncertainty level that is lower than 0.03%. The EMIS, which is used to measure the spectrum radiance on the reflected solar band, is designed to optimize the signal-to-noise ratio and polarization. The radiometric scale of the SCAR is converted and transferred to the EMIS by the BTC to improve the measurement accuracy and long-term stability. The payload of the radiometric benchmark on the reflected solar band has been under development since 2018. The investigation results provide the theoretical and experimental basis for the development of the reflected solar band benchmark payload. It is important to improve the measurement accuracy and long-term stability of space remote sensing and provide key data for climate change and earth radiation studies.

scholarly journals An Integral Field Unit Based on Parabolic Mirror

2020 ◽  
pp. short48-1-short48-7
Author(s):  
Mariia Orekhova ◽  
Alexey Bakholdin
Keyword(s):  
Spatial Resolution ◽  
Optical System ◽  
High Spectral Resolution ◽  
Parabolic Mirror ◽  
Input Field ◽  
Integral Field Spectroscopy ◽  
System Solution ◽  
Main Mirror ◽  
Field Unit ◽  
Integral Field

Recently many modern instruments and systems have been developed to study the Sun. For that, spectral instruments with high spectral resolution are most often used. It is relevant to achieve high spatial resolution along with spectral one for many scientific tasks. In practice, the achievement of both high spectral and spatial resolution can be done by the use of integral field spectroscopy. Current paper is devoted to searching for a system solution for an integral field unit (IFU), which will be implemented to the optical system of solar telescopecoronagraph. The diameter of the main mirror is D = 3 m. Telescope’s working spectral range is ∆λ = 390 − 1600 nm. The integral field unit is based on reflective elements. It divides the input field of a rectangular shape with a size of 0.7500 ×1200(0.145 mm×2.327 mm) into 8 parts with a size of 0.09400×9600(0.018 mm×18.617 mm) each. The possibility of creating an IFU optical system using a parabolic mirror for all (eight) channels is shown. The quality of the optical system was evaluated, as well as the effect of vignetting on the slicing mirrors.

scholarly journals High resolution NO<sub>2</sub> remote sensing from the Airborne Prism EXperiment (APEX) imaging spectrometer

2012 ◽  
Vol 5 (2) ◽  
pp. 2449-2486 ◽  
Author(s):  
C. Popp ◽  
D. Brunner ◽  
A. Damm ◽  
M. Van Roozendael ◽  
C. Fayt ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Air Quality ◽  
Spatial Resolution ◽  
In Situ Measurements ◽  
High Signal ◽  
Waste Incinerator ◽  
Imaging Spectrometer ◽  
Airborne Measurements ◽  
Spectrometer Data

Abstract. We present and evaluate the retrieval of high spatial resolution maps of NO2 vertical column densities (VCD) from the Airborne Prism EXperiment (APEX) imaging spectrometer. APEX is a novel instrument providing airborne measurements of unique spectral and spatial resolution and coverage as well as high signal stability. In this study, we use spectrometer data acquired over Zurich, Switzerland, in the morning and late afternoon during a flight campaign on a cloud-free summer day in June 2010. NO2 VCD are derived with a two-step approach usually applied to satellite NO2 retrievals, i.e. a DOAS analysis followed by air mass factor calculations based on radiative transfer computations. Our analysis demonstrates that APEX is clearly sensitive to NO2 VCD above typical European tropospheric background abundances (>1 × 1015 molec cm−2). The two-dimensional maps of NO2 VCD reveal a very plausible spatial distribution with strong gradients around major NOx sources (e.g. Zurich airport, waste incinerator, motorways) and low NO2 in remote areas. The morning overflights resulted in generally higher NO2 VCD and a more distinct pattern than the afternoon overflights which can be attributed to the meteorological conditions prevailing during that day (development of the boundary layer and increased wind speed in the afternoon) as well as to photochemical loss of NO2. The remotely sensed NO2 VCD are also highly correlated with ground-based in-situ measurements from local and national air quality networks (R=0.73). Airborne NO2 remote sensing using APEX will be valuable to detect NO2 emission sources, to provide input for NO2 emission modeling, and to establish links between in-situ measurements, air quality models, and satellite NO2 products.

scholarly journals High-resolution NO<sub>2</sub> remote sensing from the Airborne Prism EXperiment (APEX) imaging spectrometer

2012 ◽  
Vol 5 (9) ◽  
pp. 2211-2225 ◽  
Author(s):  
C. Popp ◽  
D. Brunner ◽  
A. Damm ◽  
M. Van Roozendael ◽  
C. Fayt ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Air Quality ◽  
Spatial Resolution ◽  
In Situ Measurements ◽  
High Signal ◽  
Waste Incinerator ◽  
Imaging Spectrometer ◽  
Airborne Measurements ◽  
Spectrometer Data

Abstract. We present and evaluate the retrieval of high spatial resolution maps of NO2 vertical column densities (VCD) from the Airborne Prism EXperiment (APEX) imaging spectrometer. APEX is a novel instrument providing airborne measurements of unique spectral and spatial resolution and coverage as well as high signal stability. In this study, we use spectrometer data acquired over Zurich, Switzerland, in the morning and late afternoon during a flight campaign on a cloud-free summer day in June 2010. NO2 VCD are derived with a two-step approach usually applied to satellite NO2 retrievals, i.e. a DOAS analysis followed by air mass factor calculations based on radiative transfer computations. Our analysis demonstrates that APEX is clearly sensitive to NO2 VCD above typical European tropospheric background abundances (>1 × 1015 molec cm−2). The two-dimensional maps of NO2 VCD reveal a very convincing spatial distribution with strong gradients around major NOx sources (e.g. Zurich airport, waste incinerator, motorways) and low NO2 in remote areas. The morning overflights resulted in generally higher NO2 VCD and a more distinct pattern than the afternoon overflights which can be attributed to the meteorological conditions prevailing during that day with stronger winds and hence larger dilution in the afternoon. The remotely sensed NO2 VCD are also in reasonably good agreement with ground-based in-situ measurements from air quality networks considering the limitations of comparing column integrals with point measurements. Airborne NO2 remote sensing using APEX will be valuable to detect NO2 emission sources, to provide input for NO2 emission modelling, and to establish links between in-situ measurements, air quality models, and satellite NO2 products.

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