scholarly journals Characterization of FIREFLY, an Imaging Spectrometer Designed for Remote Sensing of Solar Induced Fluorescence

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4682
Author(s):  
Ian Paynter ◽  
Bruce Cook ◽  
Lawrence Corp ◽  
Jyoteshwar Nagol ◽  
Joel McCorkel
Keyword(s):  
Remote Sensing ◽  
Shot Noise ◽  
Dark Current ◽  
Red Light ◽  
Light Yield ◽  
Stray Light ◽  
Integrating Sphere ◽  
Oxygen Absorption ◽  
Detector Response ◽  
Absorption Features

Solar induced fluorescence (SIF) is an ecological variable of interest to remote sensing retrievals, as it is directly related to vegetation composition and condition. FIREFLY (fluorescence imaging of red and far-red light yield) is a high performance spectrometer for estimating SIF. FIREFLY was flown in conjunction with NASA Goddard’s lidar, hyperspectral, and thermal (G-LiHT) instrument package in 2017, as a technology demonstration for airborne retrievals of SIF. Attributes of FIREFLY relevant to SIF retrieval, including detector response and linearity; full-width at half maximum (FWHM); stray light; dark current; and shot noise were characterized with a combination of observations from Goddard’s laser for absolute measurement of radiance calibration facility; an integrating sphere; controlled acquisitions of known targets; in-flight acquisitions; and forward modelling. FWHM, stray light, and dark current were found to be of acceptable magnitude, and characterized to within acceptable limits for SIF retrieval. FIREFLY observations were found to represent oxygen absorption features, along with a large number of solar absorption features. Shot noise was acceptable for direct SIF retrievals at native resolution, but indirect SIF retrievals from absorption features would require spatial aggregation, or repeated observations of targets.

Optical Design and Stray-Light Analysis of Urban Night-Light Remote Sensing Imaging System

2020 ◽  
Vol 57 (1) ◽  
pp. 012201
Author(s):  
姜守望 Jiang Shouwang ◽  
夏振涛 Xia Zhentao ◽  
孙永雪 Sun Yongxue ◽  
王珂 Wang Ke
Keyword(s):  
Remote Sensing ◽  
Imaging System ◽  
Optical Design ◽  
Stray Light

STANDOFF SENSING AND IMAGING OF EXPLOSIVE RELATED CHEMICAL AND BIO-CHEMICAL MATERIALS USING THz-TDS

2007 ◽  
Vol 17 (02) ◽  
pp. 239-249 ◽  
Author(s):  
Hua Zhong ◽  
Albert Redo-Sanchez ◽  
Xi-Cheng Zhang
Keyword(s):  
Remote Sensing ◽  
Glutamic Acid ◽  
Time Domain ◽  
Large Scale ◽  
Imaging System ◽  
Terahertz Time Domain Spectroscopy ◽  
Multiple Absorption ◽  
Thz Absorption ◽  
Absorption Features ◽  
Chemical Materials

We report the sensing and imaging of explosive related chemical and bio-chemical materials by using terahertz time domain spectroscopy (THz-TDS) at standoff distance. The 0.82 THz absorption peak of RDX is observed at a distance up to 30 m away from the emitter and receiver. Multiple absorption features of RDX, 2,4-DNT and Glutamic Acid are identified by using a large scale 2-D imaging system. These results support the feasibility of using THz-TDS technique in remote sensing and detection of chemical materials.

scholarly journals Novel ray tracing method for stray light suppression from ocean remote sensing measurements

2016 ◽  
Vol 24 (10) ◽  
pp. 10232 ◽  
Author(s):  
Eunsong Oh ◽  
Jinsuk Hong ◽  
Sug-Whan Kim ◽  
Young-Je Park ◽  
Seong-Ick Cho
Keyword(s):  
Remote Sensing ◽  
Ray Tracing ◽  
Stray Light ◽  
Ray Tracing Method ◽  
Ocean Remote Sensing ◽  
Tracing Method

Development of an integrating sphere calibration method for Cimel sunphotometers in China aerosol remote sensing network

Particuology ◽  
2014 ◽  
Vol 13 ◽  
pp. 88-99 ◽  
Author(s):  
Ran Tao ◽  
Huizheng Che ◽  
Quanliang Chen ◽  
Yaqiang Wang ◽  
Junying Sun ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Calibration Method ◽  
Integrating Sphere ◽  
Aerosol Remote Sensing

scholarly journals Negative after-images and successive contrast with pure spectral colours

1914 ◽  
Vol 87 (594) ◽  
pp. 190-191 ◽  
Keyword(s):  
Red Light ◽  
The Other ◽  
Stray Light ◽  
Normal Position ◽  
Ruby Glass ◽  
Vertical Band ◽  
Deep Blue ◽  
Green Glass

In a recent paper* Prof. Burch has criticised our results on “Negative After-Images and Successive Contrast with Pure Spectral Colours.” Prof. Burch suggests that the change in blue and violet obtained after fatigue with red light may be explained on the Young theory, if the stray light, which we stated was present, be taken into consideration. He states that the reason, on this theory, why the violet appeared bluer and darker after fatigue to red was due to the elimination of the red component in the stray light. In consequence of this criticism we have since repeated our experiments, taking the most minute precautions to exclude stray light by covering the whole apparatus and head of the observer with black velvet. When these most minute precautions were taken to prevent the admixture of red or other light the results were exactly the same as before. The experiments were conducted as follows: A region of pure violet, λ 4368- λ 4572, was isolated in the Edridge-Green spectrometer, a deep blue-green glass quite opaque to red being placed in front of the slit, so that no red light could enter the instrument. A region of pure red, λ 6360- λ 6570, was isolated in another spectrometer, deep ruby glass being placed in front of the slit so that nothing but red light could enter the instrument. The eye was then fatigued as before, one eye being vertically above the other, for 20 seconds, and the after-image projected upon a narrow vertical band in the violet region after turning the eyes round into the normal position, so that the two images crossed at right angles. The result was exactly the same as stated previously by us, the region of violet crossed by the after-image appeared bluer and darker.

scholarly journals MAPPING OF FOLIAR CONTENT USING RADIATIVE TRANSFER MODELING AND VIS-NIR HYPERSPECTRAL CLOSE-RANGE REMOTE-SENSING

2015 ◽  
Vol XL-3/W3 ◽  
pp. 467-472 ◽  
Author(s):  
S. Jay ◽  
R. Bendoula ◽  
X. Hadoux ◽  
N. Gorretta
Keyword(s):  
Remote Sensing ◽  
Radiative Transfer ◽  
Spatial Resolution ◽  
Near Infrared ◽  
Hyperspectral Data ◽  
Hyperspectral Images ◽  
Radiative Transfer Model ◽  
Integrating Sphere ◽  
Leaf Angle ◽  
Transfer Model

Most methods for retrieving foliar content from hyperspectral data are well adapted either to remote-sensing scale, for which each spectral measurement has a spatial resolution ranging from a few dozen centimeters to a few hundred meters, or to leaf scale, for which an integrating sphere is required to collect the spectral data. In this study, we present a method for estimating leaf optical properties from hyperspectral images having a spatial resolution of a few millimeters or centimeters. In presence of a single light source assumed to be directional, it is shown that leaf hyperspectral measurements can be related to the directional hemispherical reflectance simulated by the PROSPECT radiative transfer model using two other parameters. The first one is a multiplicative term that is related to local leaf angle and illumination zenith angle. The second parameter is an additive specular-related term that models BRDF effects. <br><br> Our model was tested on visible and near infrared hyperspectral images of leaves of various species, that were acquired under laboratory conditions. Introducing these two additional parameters into the inversion scheme leads to improved estimation results of PROSPECT parameters when compared to original PROSPECT. In particular, the RMSE for local chlorophyll content estimation was reduced by 21% (resp. 32%) when tested on leaves placed in horizontal (resp. sloping) position. Furthermore, inverting this model provides interesting information on local leaf angle, which is a crucial parameter in classical remote-sensing.

scholarly journals Using spectral mixture analysis of hyperspectral remote sensing data to map lithology of the Sarfartoq carbona tite complex, southern West Greenland

1969 ◽  
Vol 17 ◽  
pp. 69-72 ◽  
Author(s):  
Enton Bedini ◽  
Tapani Tukiainen
Keyword(s):  
Remote Sensing ◽  
Wavelength Region ◽  
Remote Sensing Data ◽  
High Spectral Resolution ◽  
Molecular Absorption ◽  
Landsat Images ◽  
Transitional Metals ◽  
Related Data ◽  
Spectral Mixture ◽  
Absorption Features

Remote sensing is the science of acquiring, processing, and interpreting images and related data acquired from aircraft and satellites that record the interaction between matter and electromagnetic energy (Sabins 1997). The 450–2500 nm wavelength region provides mineralogical information based on analysis of electronic absorption features in transitional metals, especially iron, and of molecular absorption features in carbonate, hydrate and hydroxide minerals (Hunt 1977). Landsat Thematic Mapper satellite im - ages are widely used to interpret structure and geology, but due to their broad spectral bandpasses Landsat images cannot identify specific minerals. However, such details can be achieved by processing and analysing data from hyperspectral sensors. These sensors provide a u nique com bination of high spatial resolution and high spectral resolution imagery of the Earth’s surface unavailable from other sources (Goetz et al. 1985).

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