scholarly journals Improvement of vicarious calibration accuracy for visible to near infrared radiometers onboard satellites based on the reflectance based method with a onsite calibration of ground based measuring instruments.

2001 ◽  
Vol 40 (3) ◽  
pp. 25-33
Author(s):  
Kohei Arai
Keyword(s):  
Near Infrared ◽  
Measuring Instruments ◽  
Vicarious Calibration ◽  
Calibration Accuracy

scholarly journals MISR Calibration and Implications for Low-Light-Level Aerosol Retrieval over Dark Water

2005 ◽  
Vol 62 (4) ◽  
pp. 1032-1052 ◽  
Author(s):  
Ralph Kahn ◽  
Wen-Hao Li ◽  
John V. Martonchik ◽  
Carol J. Bruegge ◽  
David J. Diner ◽  
...  
Keyword(s):  
Optical Thickness ◽  
Near Infrared ◽  
Light Level ◽  
Single Scattering ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Aerosol Layer ◽  
Radiometric Calibration ◽  
Low Light ◽  
Vicarious Calibration

Abstract Studying aerosols over ocean is one goal of the Multiangle Imaging Spectroradiometer (MISR) and other spaceborne imaging systems. But top-of-atmosphere equivalent reflectance typically falls in the range of 0.03 to 0.12 at midvisible wavelengths and can be below 0.01 in the near-infrared, when an optically thin aerosol layer is viewed over a dark ocean surface. Special attention must be given to radiometric calibration if aerosol optical thickness, and any information about particle microphysical properties, are to be reliably retrieved from such observations. MISR low-light-level vicarious calibration is performed in the vicinity of remote islands hosting Aerosol Robotic Network (AERONET) sun- and sky-scanning radiometers, under low aerosol loading, low wind speed, relatively cloud free conditions. MISR equivalent reflectance is compared with values calculated from a radiative transfer model constrained by coincident, AERONET-retrieved aerosol spectral optical thickness, size distribution, and single scattering albedo, along with in situ wind measurements. Where the nadir view is not in sun glint, MISR equivalent reflectance is also compared with Moderate Resolution Imaging Spectroradiometer (MODIS) reflectance. The authors push the limits of the vicarious calibration method’s accuracy, aiming to assess absolute, camera-to-camera, and band-to-band radiometry. Patterns repeated over many well-constrained cases lend confidence to the results, at a few percent accuracy, as do additional vicarious calibration tests performed with multiplatform observations taken during the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) campaign. Conclusions are strongest in the red and green bands, but are too uncertain to accept for the near-infrared. MISR nadir-view and MODIS low-light-level absolute reflectances differ by about 4% in the blue and green bands, with MISR reporting higher values. In the red, MISR agrees with MODIS band 14 to better than 2%, whereas MODIS band 1 is significantly lower. Compared to the AERONET-constrained model, the MISR aft-viewing cameras report reflectances too high by several percent in the blue, green, and possibly the red. Better agreement is found in the nadir- and the forward-viewing cameras, especially in the blue and green. When implemented on a trial basis, calibration adjustments indicated by this work remove 40% of a 0.05 bias in retrieved midvisible aerosol optical depth over dark water scenes, produced by the early postlaunch MISR algorithm. A band-to-band correction has already been made to the MISR products, and the remaining calibration adjustments, totaling no more than a few percent, are planned.

scholarly journals Removal of Contaminated Pixels from the Desert Target for AVHRR Vicarious Calibration

2009 ◽  
Vol 26 (7) ◽  
pp. 1354-1366 ◽  
Author(s):  
Fangfang Yu ◽  
Xiangqian Wu
Keyword(s):  
Vegetation Index ◽  
Near Infrared ◽  
Normalized Difference Vegetation Index ◽  
Dust Storms ◽  
Screening Methods ◽  
Vegetation Growth ◽  
Vicarious Calibration ◽  
Calibration Device ◽  
Libyan Desert ◽  
Cloud Screening

Abstract Desert-based vicarious calibration plays an important role in generating long-term reliable satellite radiances for the visible and near-infrared channels of the Advanced Very High Resolution Radiometer (AVHRR). Lacking an onboard calibration device, the AVHRR relies on reflected radiances from a target site, for example, a large desert, to calibrate its solar reflective channels. While the radiometric characteristics of the desert may be assumed to be stable, the reflected radiances from the target can occasionally be affected by the presence of clouds, sand storms, vegetation, and wet surfaces. These contaminated pixels must be properly identified and removed to ensure calibration performance. This paper describes an algorithm for removing the contaminated pixels from AVHRR measurements taken over the Libyan Desert based on the characteristics of consistent normalized difference vegetation index (NDVI) land-cover stratification. An NDVI histogram-determined threshold is first applied to screen pixels contaminated with vegetation in each individual AVHRR observation. The resulting analyses show that the vegetation growth inside the desert target has a negligibly small impact on the AVHRR operational calibration results. Two criteria based on the maximum NDVI compositing technique are then employed to remove pixels contaminated with clouds, severe sand storms, and wet sand surfaces. Compared to other cloud-screening methods, this algorithm is capable of not only identifying high-reflectance clouds, but also removing the low reflectance of wet surfaces and the nearly indifferent reflectance of severe dust storms. The use of clear pixels appears to improve AVHRR calibration accuracy in the first 3–4 yr after satellite launch.

Calibration Accuracy Evaluation of Visible and Near-Infrared Bands of FY-3B MERIS

2020 ◽  
Vol 40 (18) ◽  
pp. 1828001
Author(s):  
何兴伟 He Xingwei ◽  
韩琦 Han Qi ◽  
冯小虎 Feng Xiaohu ◽  
康宁 Kang Ning
Keyword(s):  
Near Infrared ◽  
Accuracy Evaluation ◽  
Calibration Accuracy

Estimating the Food Processing Characteristics of Pulses by near Infrared Spectroscopy, Using Ground or Whole Samples

1998 ◽  
Vol 6 (1) ◽  
pp. 213-220 ◽  
Author(s):  
P.C. Flinn ◽  
R.G. Black ◽  
L. Iyer ◽  
J.B. Brouwer ◽  
C. Meares
Keyword(s):  
Infrared Spectroscopy ◽  
Functional Properties ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Chemical Constituents ◽  
Successful Implementation ◽  
Field Peas ◽  
Calibration Accuracy ◽  
Dehulling Efficiency

The use of near infrared spectroscopy (NIR) was investigated for its ability to predict a range of chemical constituents (protein, moisture, fat, ash, total dietary fibre) and functional properties (100 seed weight, hydration capacity, hull percentage, dehulling efficiency, colour, cooking quality) of field peas and chickpeas. NIR calibrations were developed using 165 samples of field peas and 151 samples of chickpeas which had been spectrally selected from larger populations encompassing two seasons. For both species, calibration accuracy was generally better on ground than whole samples for chemical composition, but better on whole than ground samples for physical or functional properties. For most properties measured, accuracy of NIR calibrations was either satisfactory or promising, but successful implementation in a breeding programme will depend on further evaluation using independent samples, broadening the sample populations or improvements in the reference methods.

Development and testing of a hardware platform for measuring instruments based on near-infrared diffuse reflection

Measurement ◽  
2016 ◽  
Vol 86 ◽  
pp. 14-25 ◽  
Author(s):  
Fábio Augusto Gentilin ◽  
Bruna Tiemi Kobo ◽  
Lucas de Souza Ribeiro ◽  
José Alexandre de França ◽  
Ana Lúcia de S.M. Felício ◽  
...  
Keyword(s):  
Near Infrared ◽  
Diffuse Reflection ◽  
Measuring Instruments ◽  
Hardware Platform

scholarly journals Vicarious calibration of COCTS-HY1C at visible and near-infrared bands for ocean color application

2019 ◽  
Vol 27 (20) ◽  
pp. A1615 ◽  
Author(s):  
Qingjun Song ◽  
Shuguo Chen ◽  
Cheng Xue ◽  
Mingsen Lin ◽  
Keping Du ◽  
...  
Keyword(s):  
Near Infrared ◽  
Ocean Color ◽  
Vicarious Calibration

Fourier Transform Near Infrared Spectroscopy Analysis of Power Plant Coal Quality

2011 ◽  
Vol 236-238 ◽  
pp. 799-803 ◽  
Author(s):  
Shuai Wang ◽  
Xin Lu Feng ◽  
Jun Zhou ◽  
Xue Mei Wang
Keyword(s):  
Energy Source ◽  
Near Infrared ◽  
Calorific Value ◽  
Measuring Instruments ◽  
Reflection Spectroscopy ◽  
Quality Of Data ◽  
Near Infrared Spectra ◽  
Infrared Reflection ◽  
Noisy Signals ◽  
Infrared Reflection Spectroscopy

Studied the correlation of near-infrared spectra data and six coal indices, found ash and calorific value has low correlations with spectra data; then use dynamic principal components PLS method predict the coal index; this method could predict Volatile and Hydrogen content better, however, the ability to predict Carbon content and Nitrogen content is lower. It is found that using reflection spectroscopy analyzes the coal need a strong energy source, because the color of coal is deep and reflection is very weak, this leads to noisy signals. Only by improving the energy source could solve the problem of poor spectra data fundamentally; spectral data mining cannot fundamentally improve the quality of data. The current near-infrared reflection spectroscopy common platform such as BRUKER is not suitable for coal analysis, analysis of coal to be better need to develop special near-infrared measuring instruments.

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