Near‐infrared detection of ammonium minerals

Geophysics ◽  
1987 ◽  
Vol 52 (7) ◽  
pp. 924-930 ◽  
Author(s):  
M. Dennis Krohn ◽  
Stephen P. Altaner
Keyword(s):  
Crystal Structure ◽  
Nitrogen Cycle ◽  
Near Infrared ◽  
Hot Spring ◽  
Ore Deposits ◽  
Infrared Detection ◽  
Spectral Features ◽  
Spectral Bands ◽  
Band Position ◽  
Infrared Spectral

Diagnostic near‐infrared spectral features have been identified for minerals with ammonium [Formula: see text] bound in the crystal structure. Spectral bands near 2.12, 2.02, and 1.56 μm are characteristic of synthetic and natural [Formula: see text] minerals. Laboratory spectra of [Formula: see text] minerals are distinct from spectra of OH‐bearing minerals and have diagnostic shifts in band position among different mineral types. [Formula: see text] minerals were detected at several mineralized hot‐spring deposits in the western U.S. by means of hand‐held and airborne instruments. Near‐infrared detection of [Formula: see text] minerals may provide useful information for prospecting for certain ore deposits and may provide a better understanding of the nitrogen cycle within geologic environments.

Investigation of the particle size-dependent near-infrared spectral features of binary mixture samples in conjunction with Monte Carlo simulation and the influence of particle size on the accuracy of quantitative analysis

The Analyst ◽  
2018 ◽  
Vol 143 (18) ◽  
pp. 4306-4315 ◽  
Author(s):  
Pham K. Duy ◽  
Seulah Chun ◽  
Yoonjeong Lee ◽  
Hoeil Chung
Keyword(s):  
Monte Carlo Simulation ◽  
Particle Size ◽  
Monte Carlo ◽  
Quantitative Analysis ◽  
Near Infrared ◽  
Spectral Variation ◽  
Spectral Features ◽  
Size Dependent ◽  
Infrared Spectral ◽  
Mixture Samples

The origin of particle size-induced near-infrared (NIR) spectral variation, which is fundamental for robust quantitative analysis, was systematically studied in conjunction with Monte Carlo simulation.

Prediction of gasoline octane numbers from near-infrared spectral features in the range 660-1215 nm

1989 ◽  
Vol 61 (4) ◽  
pp. 313-320 ◽  
Author(s):  
Jeffrey J. Kelly ◽  
Clyde H. Barlow ◽  
Thomas M. Jinguji ◽  
James B. Callis
Keyword(s):  
Near Infrared ◽  
Spectral Features ◽  
Infrared Spectral

Variation in understory and canopy reflectance during stand development in Finnish coniferous forests

2015 ◽  
Vol 45 (8) ◽  
pp. 1077-1085 ◽  
Author(s):  
Nea Kuusinen ◽  
Pauline Stenberg ◽  
Erkki Tomppo ◽  
Pierre Bernier ◽  
Frank Berninger
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Boreal Forests ◽  
Near Infrared ◽  
Spectral Band ◽  
Stand Development ◽  
Area Index ◽  
Spectral Bands ◽  
Site Fertility ◽  
Infrared Spectral

Inherent variability in the spectral properties of boreal forests complicates the retrieval of canopy properties such as canopy leaf area index from satellite images. Understanding the drivers of this variability could help provide better estimates of desired canopy cover properties. Field plot data from the Finnish National Forest Inventory and Landsat thematic mapper (TM) images were used to investigate the variation in canopy and understory reflectance during stand development in coniferous boreal forests. Spectral data for each plot were obtained from the Landsat pixel within which the plot center coordinates fell. Nonlinear unmixing was used to estimate the bidirectional reflectance factors (BRFs) of the “sunlit understory” and “canopy and shaded ground” components by site fertility and stand development classes. A forest albedo model was used to estimate the contribution of diffuse radiation reflected downwards from the canopy to the sunlit understory component. The sunlit understory BRF in the near-infrared spectral band decreased as the site fertility decreased and the forest matured, whereas the sunlit understory BRFs in the red and shortwave-infrared spectral bands concurrently increased. The BRFs of the canopy and shaded ground component decreased slightly during stand development, mostly in the near-infrared spectral band. Adding the diffuse contribution to the sunlit understory component changed the estimated component BRFs only a little (0.1%–1.7%) compared with those obtained using a linear mixing assumption. This effect was largest in the near-infrared spectral band and smallest in the red spectral band. For Norway spruce plots, the measured and estimated forest variables were well correlated with the BRFs in all of the studied spectral bands, but for the Scots pine plots, the correlations were notably weaker. Results show a greater importance of the fraction of visible sunlit understory on forest reflectance in Scots pine than in Norway spruce forests.

scholarly journals Modeling radiative transfer in tropical rainforest canopies: sensitivity of simulated albedo to canopy architectural and optical parameters

2011 ◽  
Vol 83 (4) ◽  
pp. 1231-1242 ◽  
Author(s):  
Sílvia N. M. Yanagi ◽  
Marcos H. Costa
Keyword(s):  
Radiative Transfer ◽  
Near Infrared ◽  
Tropical Rainforest ◽  
Spectral Band ◽  
Canopy Structure ◽  
Optical Parameters ◽  
Strong Response ◽  
Spectral Bands ◽  
Infrared Spectral ◽  
Integrated Biosphere Simulator

This study evaluates the sensitivity of the surface albedo simulated by the Integrated Biosphere Simulator (IBIS) to a set of Amazonian tropical rainforest canopy architectural and optical parameters. The parameters tested in this study are the orientation and reflectance of the leaves of upper and lower canopies in the visible (VIS) and near-infrared (NIR) spectral bands. The results are evaluated against albedo measurements taken above the K34 site at the INPA (Instituto Nacional de Pesquisas da Amazônia) Cuieiras Biological Reserve. The sensitivity analysis indicates a strong response to the upper canopy leaves orientation (x up) and to the reflectivity in the near-infrared spectral band (rNIR,up), a smaller sensitivity to the reflectivity in the visible spectral band (rVIS,up) and no sensitivity at all to the lower canopy parameters, which is consistent with the canopy structure. The combination of parameters that minimized the Root Mean Square Error and mean relative error are Xup = 0.86, rVIS,up = 0.062 and rNIR,up = 0.275. The parameterizations performed resulted in successful simulations of tropical rainforest albedo by IBIS, indicating its potential to simulate the canopy radiative transfer for narrow spectral bands and permitting close comparison with remote sensing products.

scholarly journals Irradiance Observations in Near-UV, Visible and Near Infrared Spectral Bands from Measurements Carried out during ATLAS-1 and EURECA-1 Missions

1994 ◽  
Vol 143 ◽  
pp. 70-71
Author(s):  
Gerard Thuillier ◽  
Michel Herse ◽  
Dietrich Labs ◽  
Paul C. Simon ◽  
Didier Gillotay ◽  
...  
Keyword(s):  
Near Infrared ◽  
Solar Spectrum ◽  
Spectral Irradiance ◽  
Solar Spectral Irradiance ◽  
Spectral Bands ◽  
Percent Difference ◽  
Infrared Spectral ◽  
Uv Visible ◽  
The One ◽  
20 Nm

For the ATLAS and EURECA missions, we have used two identical instruments to measure the absolute solar spectral irradiance from 180 to 3200 nm. These instruments are calibrated by use of a blackbody and a set of lamp standards. The measurements are carried out with 1 nm bandpass up to 800 nm and 20 nm above. The instruments and calibration procedures are described by Thuillier et al. (1981). The platform capability of instruments retrieval after measurements allows a post-flight calibration which is essential for accurate measurements. The main results obtained up to now are:- In the UV, the ATLAS-1 and EURECA-1 solar spectral irradiance are consistent with the SpaceLab 1 data obtained in 1983 (Labs et al. 1987). Figure 1 shows the ATLAS 1 and SL 1 spectra. The origin of the existing differences is presently under investigation.- In the visible domain, our measurements agree with the solar spectrum from Neckel & Labs (1984) within a few percent difference at certain wavelength.- In the IR domain, the preliminary processing shows a spectrum close to the one obtained by Thekaekara (1974).

scholarly journals Rapid identification of Lactobacillus species using near infrared spectral features of bacterial colonies

2019 ◽  
Vol 27 (4) ◽  
pp. 302-313
Author(s):  
Jiyong Shi ◽  
Xuetao Hu ◽  
Xiaobo Zou ◽  
Zhiming Guo ◽  
Mel Holmes ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Near Infrared ◽  
Rapid Identification ◽  
Lactobacillus Species ◽  
Support Vector ◽  
Spectral Features ◽  
Mid Infrared ◽  
Near Infrared Spectra ◽  
Infrared Spectral ◽  
Chemical Groups

The feasibility of rapid identification of Lactobacillus species using near-infrared spectral features coupled with chemometrics was investigated. First, bacterial colonies of 11 Lactobacillus strains covering four species ( Lactobacillus casei, Lactobacillus reuteri, Lactobacillus brevis, and Lactobacillus fermentum) were cultured using the spread-plate technique. Near-infrared spectra data of the Lactobacillus species were collected directly from the bacterial colonies. Second, 10 wavenumbers were selected from the near-infrared spectra data using uninformative variables elimination and genetic algorithm, and calibration models based on the 10 selected wavenumbers were built using least squares support vector machine. The identification rates for the prediction set and validation set were 89.04 and 85%, respectively. Third, chemical groups of the Lactobacillus cells contributing to the identification of the Lactobacillus strains were identified using mid infrared. The results of mid infrared data analysis indicated that 9 chemical groups could be considered characteristics for categorizing the 11 Lactobacillus strains. The relationship between the 10 selected wavenumbers and identified chemical groups was identified, which supported the satisfactory performance of the least squares support vector machine calibration model. This study demonstrated that near-infrared spectral features of bacterial colonies could be used for Lactobacillus typing at the strain level.

scholarly journals Operational algae bloom detection in the Baltic Sea using GIS and AVHRR data

Baltica ◽  
2016 ◽  
Vol 29 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Marcin Kulawiak
Keyword(s):  
Baltic Sea ◽  
Algal Blooms ◽  
Near Infrared ◽  
Sea Water ◽  
The Baltic Sea ◽  
Spectral Bands ◽  
Monitoring Frequency ◽  
Avhrr Data ◽  
Infrared Spectral ◽  
The Baltic

During the blooming season, algal colonies can, in extreme cases, cover up to 200 000 square kilometres of the Baltic Sea water surface. Because the position and shape of the blooms may significantly change in a very short time due to the influence of wind and waves, regular monitoring of the blooms’ development is necessary. Currently, the desired monitoring frequency may only be achieved by means of remote sensing. The article presents a novel method of AVHRR data processing for the purpose of detection of algal blooms in the Baltic Sea. Instead of analysing the value of spectral reflectance of the algae, the algorithm analyses the frequency distribution of normalized difference in reflectance between the visible and near-infrared spectral bands. The proposed method has been implemented and tested as part of an operational Geographic Information System.

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