scholarly journals Determination of Spectral and Broadband Albedos in Visible-near Infrared Bands for Different Phenophases of Wheat Using Hemispherical Directional Reflectance Measurements

2021 ◽  
Vol 8 (4) ◽  
pp. 460-466
Author(s):  
Manoj LUNAGARİA
Keyword(s):  
Near Infrared ◽  
Reflectance Measurements ◽  
Directional Reflectance

Solid Dosage Form Analysis by near Infrared Spectroscopy: Comparison of Reflectance and Transmittance Measurements Including the Determination of Effective Sample Mass

2002 ◽  
Vol 10 (4) ◽  
pp. 233-245 ◽  
Author(s):  
Meenakshy Iyer ◽  
Hannah R. Morris ◽  
James K. Drennen
Keyword(s):  
Near Infrared ◽  
Empirical Method ◽  
Infrared Analysis ◽  
Compression Force ◽  
Sampling Depth ◽  
Sample Mass ◽  
Form Analysis ◽  
Solid Dosage ◽  
Reflectance Measurements

Investigations into the near infrared analysis of intact tablets allow comparison of the reflectance and transmittance methodologies. The studies involved estimation of the effective sample mass and the effect of sample inhomogeneities. An empirical method for determining effective sample mass used tablets of varying thickness and constant compression force. Tablets containing a range of cimetidine concentrations were used to study the effect of drug concentration on effective sample mass as a function of wavelength of observation. Effective sampling depth was between 1.9 and 2.7 mm for reflectance measurements. With transmittance measurements, signal was completely attenuated when tablet thickness was greater than 3.4–4.9 mm, depending on the wavelength of observation. Multi-layered tablets provided a means of probing the effect of sample inhomogeneity. Both reflectance and transmittance measurements may be sensitive to sample inhomogeneity. Transmittance measurements are sensitive to pathlength variations.

Near Infrared Spectroscopy Used in Purification and Determination of Pharmaceutical Cocrystal

2013 ◽  
Vol 41 (12) ◽  
pp. 1928
Author(s):  
Zong-Liang CHI ◽  
Miao-Miao WANG ◽  
Xiao-Dong CONG ◽  
Shao-Guang LIU ◽  
Bao-Chang CAI
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Pharmaceutical Cocrystal

scholarly journals Semi-Automatic Fractional Snow Cover Monitoring from Near-Surface Remote Sensing in Grassland

2021 ◽  
Vol 13 (11) ◽  
pp. 2045
Author(s):  
Anaí Caparó Bellido ◽  
Bradley C. Rundquist
Keyword(s):  
Snow Cover ◽  
Near Infrared ◽  
Accuracy Assessment ◽  
Important Variable ◽  
Field Station ◽  
Near Surface ◽  
Fractional Snow Cover ◽  
Rgb Images ◽  
Phenological Metrics

Snow cover is an important variable in both climatological and hydrological studies because of its relationship to environmental energy and mass flux. However, variability in snow cover can confound satellite-based efforts to monitor vegetation phenology. This research explores the utility of the PhenoCam Network cameras to estimate Fractional Snow Cover (FSC) in grassland. The goal is to operationalize FSC estimates from PhenoCams to inform and improve the satellite-based determination of phenological metrics. The study site is the Oakville Prairie Biological Field Station, located near Grand Forks, North Dakota. We developed a semi-automated process to estimate FSC from PhenoCam images through Python coding. Compared with previous research employing RGB images only, our use of the monochrome RGB + NIR (near-infrared) reduced pixel misclassification and increased accuracy. The results had an average RMSE of less than 8% FSC compared to visual estimates. Our pixel-based accuracy assessment showed that the overall accuracy of the images selected for validation was 92%. This is a promising outcome, although not every PhenoCam Network system has NIR capability.

Sign in / Sign up

Export Citation Format

Share Document