scholarly journals Extending Nighttime Combustion Source Detection Limits with Short Wavelength VIIRS Data

2019 ◽  
Vol 11 (4) ◽  
pp. 395 ◽  
Author(s):  
Christopher Elvidge ◽  
Mikhail Zhizhin ◽  
Kimberly Baugh ◽  
Feng Hsu ◽  
Tilottama Ghosh
Keyword(s):  
Curve Fitting ◽  
Short Wavelength ◽  
Detection Limits ◽  
Source Area ◽  
High Energy ◽  
Source Detection ◽  
Combustion Source ◽  
Low Light ◽  
Spectral Bands ◽  
Combustion Sources

The Visible Infrared Imaging Radiometer Suite (VIIRS) collects low light imaging data at night in five spectral bands. The best known of these is the day/night band (DNB) which uses light intensification for imaging of moonlit clouds in the visible and near-infrared (VNIR). The other four low light imaging bands are in the NIR and short-wave infrared (SWIR), designed for daytime imaging, which continue to collect data at night. VIIRS nightfire (VNF) tests each nighttime pixel for the presence of sub-pixel IR emitters across six spectral bands with two bands each in three spectral ranges: NIR, SWIR, and MWIR. In pixels with detection in two or more bands, Planck curve fitting leads to the calculation of temperature, source area, and radiant heat using physical laws. An analysis of January 2018 global VNF found that inclusion of the NIR and SWIR channels results in a doubling of the VNF pixels with temperature fits over the detection numbers involving the MWIR. The addition of the short wavelength channels extends detection limits to smaller source areas across a broad range of temperatures. The VIIRS DNB has even lower detection limits for combustion sources, reaching 0.001 m2 at 1800 K, a typical temperature for a natural gas flare. Comparison of VNF tallies and DNB fire detections in a 2015 study area in India found the DNB had 15 times more detections than VNF. The primary VNF error sources are false detections from high energy particle detections (HEPD) in space and radiance saturation on some of the most intense events. The HEPD false detections are largely eliminated in the VNF output by requiring multiband detections for the calculation of temperature and source size. Radiance saturation occurs in about 1% of the VNF detections and occurs primarily in the M12 spectral band. Inclusion of the radiances affected by saturation results in temperature and source area calculation errors. Saturation is addressed by identifying the presence of saturation and excluding those radiances from the Planck curve fitting. The extremely low detection limits for the DNB indicates that a DNB fire detection algorithm could reveal vast numbers of combustion sources that are undetectable in longer wavelength VIIRS data. The caveats with the DNB combustion source detection capability is that it should be restricted to pixels that are outside the zone of known VIIRS detected electric lighting.

scholarly journals Braided-river and hyperconcentrated-flow deposits from the Carboniferous of the Lublin Basin (SE Poland) – a sedimentological study of core data

Geologos ◽  
2012 ◽  
Vol 18 (3) ◽  
pp. 135-161 ◽  
Author(s):  
Maria I. Waksmundzka
Keyword(s):  
Source Area ◽  
High Energy ◽  
Coarse Grained ◽  
Type I ◽  
Braided River ◽  
River Channels ◽  
Fine Grained ◽  
Braided Rivers ◽  
Base Level ◽  
Se Poland

Abstract Fining-upwards cyclothems found in five boreholes in the Carboniferous (Lower Bashkirian) of the Lublin Basin were analysed sedimentologically. It was established that the cyclothems represent fluvial deposits, and the lithofacies were grouped into lithofacies associations. Most lithofacies associations represent three types of sand-bed braided rivers: (1) high-energy, (2) deep and (3) distal sheetflood-affected. Other associations represent hyperconcentrated flows. Both coarse-grained (type I) and fine-grained (types IIa and IIb) occur among the fining-upward cyclothems. The formation of most thick cyclothems was related mainly to allocyclic factors, i.e. a decrease in the river’s gradient. The thickest fining-upward cyclothems are characteristic of hyperconcentrated flows and braided-river channels. The aggradation ratios were commonly high. During the early Namurian C and early Westphalian A (Early Bashkirian), the eastern part of the Lublin Basin was located close to the source area. The sedimentary succession developed due to a transition from high-energy braidedrivers and hyperconcentrated flows to lower-energy braided rivers, controlled by a rise of the regional base level.

scholarly journals Comparison of Fracture Delineation Methods in Anteroposterior Pelvic Radiographs

2020 ◽  
Vol 2 (2) ◽  
pp. 17-29
Author(s):  
Ligisha P ◽  
Bhavani S
Keyword(s):  
Curve Fitting ◽  
Visual Complexity ◽  
High Energy ◽  
Pelvic Fractures ◽  
Detection Methods ◽  
Pelvic Bone ◽  
Fracture Detection ◽  
Vehicle Collision ◽  
Energy Incident ◽  
Elder People

Pelvic fractures are very difficult to detect due to the visual complexity of the pelvic bone. Pelvic fracture occurs less frequently, only when there is a high energy event such as fall from a height or vehicle collision. In elder people and in osteoporosis patients even a low energy incident may cause fracture. The paper includes the comparison of three different fracture detection methods – GLCM and ANN based, Statistical curve fitting and classifier based and finally statistical curve fitting and ANN based method.

scholarly journals ANALYSIS OF APPLICATION OF CONTEMPORARY NIGHT VISION GOGGLES ON THE BASIS OF ELECTRONIC-OPTICAL CONVERTER BY THE HELICOPTER CREWS. PROSPECTIVE HELICOPTER OPTOELECTRONIC SYSTEMS OF AERIAL RECONNAISSANCE/SURVEILLANCE

2020 ◽  
pp. 50-55
Author(s):  
O. Kuzmich ◽  
V. Kuznetsov ◽  
M. Andrushko
Keyword(s):  
Search And Rescue ◽  
Night Vision ◽  
Target Acquisition ◽  
Optoelectronic System ◽  
Night Time ◽  
Low Light ◽  
Spectral Bands ◽  
Light Levels ◽  
Aerial Reconnaissance ◽  
Optoelectronic Systems

The paper studies the matters of using of night vision goggles by the helicopter crews of the State Aviation of Ukraine. The analysis of the perspective systems that can replace night vision goggles based on electronic-optical converter and provide round-the-clock and all-weather flights, landing of the helicopter on unprepared and unlit areas in poor visibility was treated. Currently, the practice of using combat and transport helicopters involves their wider use in the night-time conditions (air warfare, delivery of goods, search-and-rescue operations). Due to low light levels, until recently, most night-time target acquisition tasks have been related with the necessities of providing the artificial target illumination, but in certain instances such illumination deteriorates visibility through an lighttight, phosphorescent atmospheric shells or it just can‟t be carried out. The need for a large number of channels included in the optoelectronic system, caused by the variety of tasks that are solved by it, as well as the imperfection of each individual channel. This forces them to be combined to improve the efficiency of the optoelectronic systems themselves, so that the disadvantages of one channel are offset by the advantages of another. In fact, it is only possible way to ensure the fulfilment of combat task by combining channels operating in different spectral bands in one scheme and by combining detection devices. It can be stated that, despite the undisputed advantages of optoelectronic systems as compared to night-vision goggles, in case of the selecting for installing on a helicopter of optoelectronic systems, it should take into account the much higher cost of optoelectronic systems compared with night-vision goggles. Therefore, the rationale for installing optoelectronic systems must be determined based on the scope of the executing tasks, which are to be conducted by a specific helicopter.

Instrumental Photon Activation and Applications in a Nuclear-Waste Inspection Purpose

2003 ◽  
Author(s):  
F. Jeanneau ◽  
M. Gmar ◽  
N. Huot ◽  
F. Laine´ ◽  
A. Lyoussi ◽  
...  
Keyword(s):  
Waste Management ◽  
Nuclear Waste ◽  
Cross Sections ◽  
Detection Limits ◽  
Current Method ◽  
High Energy ◽  
Monte Carlo Code ◽  
Photon Activation ◽  
Simulation Code ◽  
Passive Noise

The development of non-destructive methods to inspect nuclear-waste containers is important for radioactive-waste management and non-proliferation purposes. This paper will present studies and results carried out by a method based on photon interrogation (photofission) which allows the determination of the actinide quantity contained in the waste. High-energy photons (produced by an electron accelerator associated with a Bremsstrahlung tungsten target) will induce photofission reactions on the actinides. Then the flux of delayed neutrons, which is directly proportional to the amount of actinides, is measured with 3He detectors. Since the beginning of 1990’s, our team in CEA has been working on the development of this method and the improvement of the existing simulation code. The two main tools will be introduced: OPERA (tool for the simulation of photonuclear reactions) which includes photonuclear cross sections in a Monte-Carlo code based on MCNP4C, and SAPHIR (Irradiation and Photon-Activation System), a device allowing experimentations for research and development programs. The applications of these tools will be illustrated mainly with two examples: 1) The feasibility study of an inspection device for old concrete containers will be reported. Two campaigns of measurements have been performed in order to determine the sensitivity and the detection limits in the case of four different types of concrete containers, in terms of nature and geometry. 2) Nuclear-waste producers and managers have been interested by the active photon interrogation possibilities to measure actinide quantity in wastes of high activity, vitrified or compacted, with constraints like a dose rate around 400 Gy/h at 27 cm from the container. The simulation-code improvement has allowed some calculations, based on the SAPHIR facility, which have shown a good linearity between the actinide mass and the number of detected neutrons, in spite of a very high passive noise and the presence of a lead protection. Several R&D programs will be also presented. On one hand, measurements are performed on real wastes, chosen for parameter which could define a limitation of the measurements, in order to improve the method and to evaluate the detection limits. For instance, tomography can be performed with this experimental device: quantity and position of actinides in the waste can be calculated. On the other hand, a new method is studied, using the delayed-gamma flux in order to quantify and to identify the different actinide isotopes contained in the waste. These methods and device offer a large panel of results in terms of measurements and simulations. Our team is now involved in several prospecting and R&D programs in order to improve the current method and to find some new applications for nuclear-waste management.

Simulation of the interaction of a high energy laser beam with the sea surface in the short wavelength infrared

2019 ◽  
Vol 58 (29) ◽  
pp. 8126
Author(s):  
Frédéric Schwenger ◽  
Norbert Scherer-Negenborn ◽  
Katrin Braesicke
Keyword(s):  
Laser Beam ◽  
Short Wavelength ◽  
High Energy ◽  
Sea Surface ◽  
Energy Laser ◽  
High Energy Laser

Recent results from the imagery of Juno’s Stellar Reference Unit

2020 ◽  
Author(s):  
Heidi Becker ◽  
James Alexander ◽  
Sushil Atreya ◽  
Scott Bolton ◽  
Martin Brennan ◽  
...  
Keyword(s):  
Satellite Images ◽  
Attitude Determination ◽  
High Energy ◽  
High Energy Particle ◽  
Energy Particle ◽  
Low Light ◽  
Jovian System ◽  
Dust Ring ◽  
Juno Mission

<p>The Juno Mission has recast its spacecraft engineering star camera as a visible wavelength science imager. Developed and primarily used to support onboard attitude determination, Juno’s Stellar Reference Unit (SRU) has been put to use as an in situ high energy particle detector for profiling Jupiter’s radiation belts and as a low light sensitive camera for exploring multiple phenomena and features of the Jovian system. Juno’s unprecedented polar orbit and closest approach of ~4000 km have yielded high resolution SRU imagery of Jupiter’s lightning and aurorae from as little as 50,000 km from the 1 bar level and unique Jovian dust ring and satellite images. We will present recent SRU results and discuss the implications for Jupiter’s atmosphere that stem from the SRU lightning observations.</p>

Lead Tungstate For High Energy Calorimetry

1994 ◽  
Vol 348 ◽  
Author(s):  
I. Dafinei ◽  
E. Auffray ◽  
P. Lecoq ◽  
M. Schneegans
Keyword(s):  
Energy Resolution ◽  
Spectroscopic Data ◽  
High Energy Physics ◽  
Light Yield ◽  
High Energy ◽  
Lead Tungstate ◽  
Low Light ◽  
Physics Experiments ◽  
Energy Physics ◽  
Detector Volume

ABSTRACTThe very large volumes needed to build a crystal calorimeter for High Energy Physics experiments bring cost considerations at the front of the stage. A reasonable compromise between cost and performances must be reached. One possible solution is to look at very dense materials like PbWO4, which will reduce the detector volume, even if the relatively low light yield will impose some limitations to the energy resolution. A review of the different results obtained by the Crystal Clear collaboration will be given for this crystal, including spectroscopic data and radiation damage measurements.

Gear efficiency estimation method through finite element and curve fitting

2021 ◽  
pp. 1-19
Author(s):  
M.F.M.A. Halim ◽  
E. Sulaiman ◽  
R.N.F.K.R. Othman
Keyword(s):  
Finite Element ◽  
Eddy Current ◽  
Curve Fitting ◽  
High Energy ◽  
Gear Ratio ◽  
Eddy Current Loss ◽  
High Energy Density ◽  
Current Loss ◽  
Finite Element Software ◽  
Gear Efficiency

The inclusion of high energy density permanent magnet (PM) in MG contributes to the high eddy current loss in magnetic gear and reduces its efficiency. There was limited research done that focused on gear efficiency behavior over a broader range of speed and in different gear ratios. In this paper, the function of gear efficiency concerning gear ratio and rotational speed is proposed. Torque and eddy current loss data were obtained through transient magnetic analysis using finite element software at several rotational ranges and gear ratios. The analytical approach through mathematical substitution was discussed to confirm the finding in the simulation. The result showed that the gear efficiency decreases as the speed increases. Nonetheless, the gear efficiency revealed improvement in efficiency as the gear ratio increases. Finally, gear efficiency behavior was modeled using the curve fitting method. Subsequently, based on the correlation study, an equation was proposed, yielding a 1% error compared to the new simulated data. With this proposed method and equation, the analysis and estimation of gear efficiency behavior over wider speed and gear ratios are simplified, thus reducing the need to perform simulation over different speeds and gear ratios.

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