scholarly journals A High-Accuracy Multiwavelength Radiometer for In Situ Measurements in the Thermal Infrared. Part II: Behavior in Field Experiments

2003 ◽  
Vol 20 (7) ◽  
pp. 1023-1033 ◽  
Author(s):  
Gérard Brogniez ◽  
Christophe Pietras ◽  
Michel Legrand ◽  
Philippe Dubuisson ◽  
Martial Haeffelin
Keyword(s):  
Field Experiments ◽  
Thermal Infrared ◽  
High Accuracy ◽  
In Situ Measurements

scholarly journals A High-Accuracy Multiwavelength Radiometer for In Situ Measurements in the Thermal Infrared. Part I: Characterization of the Instrument

2000 ◽  
Vol 17 (9) ◽  
pp. 1203-1214 ◽  
Author(s):  
Michel Legrand ◽  
Christophe Pietras ◽  
Gérard Brogniez ◽  
Martial Haeffelin ◽  
Nader Khalil Abuhassan ◽  
...  
Keyword(s):  
Thermal Infrared ◽  
High Accuracy ◽  
In Situ Measurements

scholarly journals Multi-angular thermal infrared emission characteristics of Bohai Sea ice based on in situ measurements

2015 ◽  
Vol 61 (229) ◽  
pp. 864-874 ◽  
Author(s):  
Jinlong Chao ◽  
Chengyu Liu ◽  
Yingjun Xu ◽  
Wei Gu ◽  
Ying Li ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Sea Ice ◽  
Bohai Sea ◽  
Robust Regression ◽  
Thermal Infrared ◽  
In Situ Measurements ◽  
Transfer Model ◽  
Emission Characteristics ◽  
Relative Emissivity

AbstractWe report on the radiative transfer process and optical properties of sea ice in the thermal infrared (TIR) band, presenting two new linear kernel driver models (Relative Emissivity Distribution Function, REDF) that describe TIR emission characteristics of smooth and rough ice. In order to test the models and determine the necessary coefficients, in situ measurements from the Bohai Sea were carried out during the 2011/12 and 2012/13 boreal winters. The results show that the relative emissivity of smooth sea ice decreases along with increasing viewing zenith angle, and the shape of the relative emissivity curve is similar to that of an ideal plane. Affected by parameters such as roughness and surface temperature distribution, the anisotropy of relative emissivity of sea ice with a high degree of roughness is stronger relative to the cosine emitter. The model coefficients were also obtained using a robust regression method based on the measured data. The presented models are more practical than the numerical radiative transfer model and can be used for multi-angular TIR remote sensing.

scholarly journals Development of a Method to Detect High Ice Water Content Environments Using Machine Learning

2020 ◽  
Vol 37 (4) ◽  
pp. 641-663
Author(s):  
Julie A. Haggerty ◽  
Allyson Rugg ◽  
Rodney Potts ◽  
Alain Protat ◽  
J. Walter Strapp ◽  
...  
Keyword(s):  
Machine Learning ◽  
False Alarm ◽  
Water Content ◽  
Field Experiments ◽  
Weather Prediction ◽  
In Situ Measurements ◽  
Probability Of Detection ◽  
Ice Water Content ◽  
Ice Water

AbstractThis paper describes development of a method for discriminating high ice water content (HIWC) conditions that can disrupt jet-engine performance in commuter and large transport aircraft. Using input data from satellites, numerical weather prediction models, and ground-based radar, this effort employs machine learning to determine optimal combinations of available information using fuzzy logic. Airborne in situ measurements of ice water content (IWC) from a series of field experiments that sampled HIWC conditions serve as training data in the machine-learning process. The resulting method, known as the Algorithm for Prediction of HIWC Areas (ALPHA), estimates the likelihood of HIWC conditions over a three-dimensional domain. Performance statistics calculated from an independent subset of data reserved for verification indicate that the ALPHA has skill for detecting HIWC conditions, albeit with significant false alarm rates. Probability of detection (POD), probability of false detection (POFD), and false alarm ratio (FAR) are 86%, 29% (60% when IWC below 0.1 g m−3 are omitted), and 51%, respectively, for one set of detection thresholds using in situ measurements. Corresponding receiver operating characteristic (ROC) curves give an area under the curve of 0.85 when considering all data and 0.69 for only points with IWC of at least 0.1 g m−3. Monte Carlo simulations suggest that aircraft sampling biases resulted in a positive POD bias and the actual probability of detection is between 78.5% and 83.1% (95% confidence interval). Analysis of individual case studies shows that the ALPHA output product generally tracks variation in the measured IWC.

The Carbon:²³⁴Thorium ratios of sinking particles in the California Current Ecosystem 2: Examination of a thorium sorption, desorption, and particle transport model

2019 ◽  
Author(s):  
Michael Stukel ◽  
Thomas Kelly
Keyword(s):  
Organic Carbon ◽  
Water Column ◽  
Particulate Organic Carbon ◽  
Transport Model ◽  
California Current ◽  
In Situ Measurements ◽  
Power Law Distribution ◽  
Sinking Particles ◽  
Organic Carbon Concentration

Thorium-234 (234Th) is a powerful tracer of particle dynamics and the biological pump in the surface ocean; however, variability in carbon:thorium ratios of sinking particles adds substantial uncertainty to estimates of organic carbon export. We coupled a mechanistic thorium sorption and desorption model to a one-dimensional particle sinking model that uses realistic particle settling velocity spectra. The model generates estimates of 238U-234Th disequilibrium, particulate organic carbon concentration, and the C:234Th ratio of sinking particles, which are then compared to in situ measurements from quasi-Lagrangian studies conducted on six cruises in the California Current Ecosystem. Broad patterns observed in in situ measurements, including decreasing C:234Th ratios with depth and a strong correlation between sinking C:234Th and the ratio of vertically-integrated particulate organic carbon (POC) to vertically-integrated total water column 234Th, were accurately recovered by models assuming either a power law distribution of sinking speeds or a double log normal distribution of sinking speeds. Simulations suggested that the observed decrease in C:234Th with depth may be driven by preferential remineralization of carbon by particle-attached microbes. However, an alternate model structure featuring complete consumption and/or disaggregation of particles by mesozooplankton (e.g. no preferential remineralization of carbon) was also able to simulate decreasing C:234Th with depth (although the decrease was weaker), driven by 234Th adsorption onto slowly sinking particles. Model results also suggest that during bloom decays C:234Th ratios of sinking particles should be higher than expected (based on contemporaneous water column POC), because high settling velocities minimize carbon remineralization during sinking.

The questions of methodology of field experiments in agriculture and crop production

2018 ◽  
Vol 1 (94) ◽  
pp. 38-44
Author(s):  
А.M. Malienkо ◽  
N.E. Borуs ◽  
N.G. Buslaeva
Keyword(s):  
Labor Productivity ◽  
Crop Production ◽  
Field Experiments ◽  
Weather Conditions ◽  
High Accuracy ◽  
Experimental Plot ◽  
Increase Labor Productivity ◽  
Biometric Parameters ◽  
Field Crops ◽  
High Condition

In the article, the results of research on the methodology for conducting studies with corn culture under various methods of sowing and weather conditions. The aim of the research was to establish and evaluate the reliability and high accuracy of the experiment, with a decrease in the area's acreage and taking one plant per repetition. Based on the results of the analysis of biometric parameters and yields, the possibility of sampling from 5 to 108 plants was established statistically and mathematically to establish the accuracy of the experiment. The established parameters of sites in experiments with maize indicate the possibility of obtaining much more information from a smaller unit of area, that is, to increase labor productivity not only with tilled crops. This is the goal of further scientific research with other field crops taking 1 plant of repetitions, observing the conditions of leveling the experimental plot according to the fertility of the soil and sowing seeds with high condition. The data obtained give grounds for continuing research on the minimum space required and the sample in the experiments.

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