scholarly journals Detection of Methane Plumes Using Airborne Midwave Infrared (3–5 µm) Hyperspectral Data

2018 ◽  
Vol 10 (8) ◽  
pp. 1237 ◽  
Author(s):  
Rebecca Scafutto ◽  
Carlos de Souza Filho
Keyword(s):  
Weather Conditions ◽  
Hyperspectral Data ◽  
Acquisition Time ◽  
Infrared Range ◽  
Emission Sources ◽  
Ambient Conditions ◽  
Low Contrast ◽  
Gas Leakage ◽  
Multiple Sensors ◽  
Midwave Infrared

Methane (CH4) display spectral features in several regions of the infrared range (0.75–14 µm), which can be used for the remote mapping of emission sources through the detection of CH4 plumes from natural seeps and leaks. Applications of hyperspectral remote sensing techniques for the detection of CH4 in the near and shortwave infrared (NIR-SWIR: 0.75–3 µm) and longwave infrared (LWIR: 7–14 µm) have been demonstrated in the literature with multiple sensors and scenarios. However, the acquisition and processing of hyperspectral data in the midwave infrared (MWIR: 3–5 µm) for this application is rather scarce. Here, a controlled field experiment was used to evaluate the potential for CH4 plume detection in the MWIR based on hyperspectral data acquired with the SEBASS airborne sensor. For comparison purposes, LWIR data were also acquired simultaneously with the same instrument. The experiment included surface and undersurface emission sources (ground stations), with flow rates ranging between 0.6–40 m3/h. The data collected in both ranges were sequentially processed using the same methodology. The CH4 plume was detected, variably, in both datasets. The gas plume was detected in all LWIR images acquired over nine gas leakage stations. In the MWIR range, the plume was detected in only four stations, wherein 18 m3/h was the lowest flux sensed. We demonstrate that the interference of target reflectance, the low contrast between plume and background and a low signal of the CH4 feature in the MWIR at ambient conditions possibly explain the inferior results observed for this range when compared to LWIR. Furthermore, we show that the acquisition time and weather conditions, including specific limits of temperature, humidity, and wind speed, proved critical for plume detection using daytime MWIR hyperspectral data.

scholarly journals AT2ES: Simultaneous Atmospheric Transmittance-Temperature-Emissivity Separation Using Online Upper Midwave Infrared Hyperspectral Images

2021 ◽  
Vol 13 (7) ◽  
pp. 1249
Author(s):  
Sungho Kim ◽  
Jungsub Shin ◽  
Sunho Kim
Keyword(s):  
Air Temperature ◽  
Atmospheric Correction ◽  
Hyperspectral Data ◽  
Hyperspectral Images ◽  
Co2 Absorption ◽  
Infrared Band ◽  
Data Regression ◽  
Midwave Infrared ◽  
Novel Method ◽  
Atmospheric Transmittance

This paper presents a novel method for atmospheric transmittance-temperature-emissivity separation (AT2ES) using online midwave infrared hyperspectral images. Conventionally, temperature and emissivity separation (TES) is a well-known problem in the remote sensing domain. However, previous approaches use the atmospheric correction process before TES using MODTRAN in the long wave infrared band. Simultaneous online atmospheric transmittance-temperature-emissivity separation starts with approximation of the radiative transfer equation in the upper midwave infrared band. The highest atmospheric band is used to estimate surface temperature, assuming high emissive materials. The lowest atmospheric band (CO2 absorption band) is used to estimate air temperature. Through onsite hyperspectral data regression, atmospheric transmittance is obtained from the y-intercept, and emissivity is separated using the observed radiance, the separated object temperature, the air temperature, and atmospheric transmittance. The advantage with the proposed method is from being the first attempt at simultaneous AT2ES and online separation without any prior knowledge and pre-processing. Midwave Fourier transform infrared (FTIR)-based outdoor experimental results validate the feasibility of the proposed AT2ES method.

Environmental Demands Associated With Community Mobility in Older Adults With and Without Mobility Disabilities

2002 ◽  
Vol 82 (7) ◽  
pp. 670-681 ◽  
Author(s):  
Anne Shumway-Cook ◽  
Aftab E Patla ◽  
Anita Stewart ◽  
Luigi Ferrucci ◽  
Marcia A Ciol ◽  
...  
Keyword(s):  
Older Adults ◽  
Weather Conditions ◽  
Grocery Store ◽  
Fisher Exact Test ◽  
Ambient Conditions ◽  
Mobility Disability ◽  
Exact Test ◽  
Mobility Function ◽  
Community Mobility ◽  
Trip Frequency

Abstract Background and Purpose. In this study, the influence of 8 dimensions of the physical environment on mobility in older adults with and without mobility disability was measured. This was done in order to identify environmental factors that contribute to mobility disability. Subjects. Subjects were 36 older adults (≥70 years of age) who were recruited from 2 geographic sites (Seattle, Wash, and Waterloo, Ontario, Canada) and were grouped according to level of mobility function (physically able [ability to walk ½ mile (0.8 km) or climb stairs without assistance], physically disabled). Methods. Subjects were observed and videotaped during 3 trips into the community (trip to grocery store, physician visit, recreational trip). Frequency of encounters with environmental features within each of the 8 dimensions was recorded. Differences in baseline characteristics and environmental encounters were analyzed using an analysis of variance or the Fisher exact test, as appropriate. Results. Mobility disability among older adults was not associated with a uniform decrease in encounters with environmental challenges across all dimensions. Environmental dimensions that differed between subjects who were physically able and those with physical disability included temporal factors, physical load, terrain, and postural transition. Dimensions that were not different included distance, density, ambient conditions (eg, light levels and weather conditions), and attentional demands. Discussion and Conclusion. Understanding the relationship of the environment to mobility is crucial to both prevention and rehabilitation of mobility disability in older adults. Among older adults, certain dimensions of the environment may disable community mobility more than others.

SOLVING THE PROBLEM OF INTER-AIRCRAFT NAVIGATION TO ENSURE FLYING IN FORMATION USING A TECHNICAL VISION SYSTEM

2021 ◽  
pp. 32-39
Author(s):  
Д.А. Смирнов ◽  
В.Г. Бондарев ◽  
А.В. Николенко
Keyword(s):  
Image Processing ◽  
Flight Control ◽  
Vision System ◽  
Weather Conditions ◽  
Infrared Range ◽  
Light Sources ◽  
Navigation Systems ◽  
Aircraft Structure ◽  
Aircraft Navigation ◽  
Technical Vision

Проведен краткий анализ как отечественных, так и зарубежных систем межсамолетной навигации. В ходе анализа были отражены недостатки систем межсамолетной навигации и представлен актуальный подход повышения точности системы навигации за счет применения системы технического зрения. Для определения местоположения ведущего самолета предлагается рассмотреть в качестве измерительного комплекса систему технического зрения, которая способна решать большой круг задач на различных этапах, в частности, и полет строем. Систему технического зрения предлагается установить на ведомом самолете с целью измерения всех параметров, необходимых для формирования автоматического управления полетом летательного аппарата. Обработка изображений ведущего самолета выполняется с целью определения координат трех идентичных точек на фоточувствительных матрицах. Причем в качестве этих точек выбираются оптически контрастные элементы конструкции летательного аппарата, например окончания крыла, хвостового оперения и т.д. Для упрощения процедуры обработки изображений возможно использование полупроводниковых источников света в инфракрасном диапазоне (например, с длиной волны λ = 1,54 мкм), что позволяет работать даже в сложных метеоусловиях. Такой подход может быть использован при автоматизации полета строем более чем двух летательных аппаратов, при этом необходимо только оборудовать системой технического зрения все ведомые самолеты группы The article provides a brief analysis of both domestic and foreign inter-aircraft navigation systems. In the course of the analysis, we found the shortcomings of inter-aircraft navigation systems and presented an up-to-date approach to improving the accuracy of the navigation system through the use of a technical vision system. To determine the location of the leading aircraft, we proposed to consider a technical vision system as a measuring complex, which is able to solve a large range of tasks at various stages, in particular, flight in formation. We proposed to install the technical vision system on the slave aircraft in order to measure all the parameters necessary for the formation of automatic flight control of the aircraft. We performed an image processing of the leading aircraft to determine the coordinates of three identical points on photosensitive matrices. Moreover, we selected optically contrasting elements of the aircraft structure as these points, for example, the end of the wing, tail, etc. To simplify the image processing procedure, it is possible to use semiconductor light sources in the infrared range (for example, with a wavelength of λ = 1.54 microns), which allows us to work even in difficult weather conditions. This approach can be used when automating a flight in formation of more than two aircraft, while it is only necessary to equip all the guided aircraft of the group with a technical vision system

scholarly journals A Deterministic Sensor Deployment Method for Target Coverage

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Ye Jiang ◽  
Shuyan Xiao ◽  
Jian Liu ◽  
Bo Chen ◽  
Bangbang Zhang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Gas Sensors ◽  
Estimation Method ◽  
Weather Conditions ◽  
Pso Algorithm ◽  
Gas Diffusion ◽  
Optimization Criterion ◽  
Sensor Deployment ◽  
Entropy Estimation ◽  
Gas Leakage

In order to monitor the gas leakage, the gas sensors are deployed conventionally in chemical industry park, with little considerations given to the gas characteristics and weather conditions, which give rise to the problems of coverage hole and coverage repetition. To solve the problems, this paper proposes a deterministic sensor deployment method with the gas diffusion models which takes into account wind speed and direction and then studies the influence of wind speed and direction on the monitoring error of gas sensors. Then, we research the deterministic deployment method of gas sensors in condition of the main wind speed and direction somewhere. Firstly, we use the CFD theory to simulate the gas diffusion situation so as to obtain the concentration value of the relevant points. Secondly, we put forward a new optimization criterion, namely, the more alarm concentration points covered by gas sensors, the coverage performance is better, and the deployment method is better. Accordingly, a new objection function is built. Thirdly, we obtain the weight values of the function using entropy estimation method. Finally, we deploy the gas sensors determinately using particle swarm optimization (PSO) algorithm. The simulation results show that the proposed method can improve the monitoring efficiency and the coverage performance of gas sensor network.

scholarly journals Graz Lagrangian Model (GRAL) for Pollutants Tracking and Estimating Sources Partial Contributions to Atmospheric Pollution in Highly Urbanized Areas

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1375
Author(s):  
Aleksey A. Romanov ◽  
Boris A. Gusev ◽  
Egor V. Leonenko ◽  
Anastasia N. Tamarovskaya ◽  
Alexander S. Vasiliev ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Landscape ◽  
Weather Conditions ◽  
Lagrangian Model ◽  
Emission Sources ◽  
Computational Domain ◽  
Surface Atmospheric Layer ◽  
Wind Speeds ◽  
High Rise ◽  
Heterogeneous Landscape

Computational modeling allows studying the air quality problems in depth and provides the best solution reducing the population risks. This research demonstrates the Graz Lagrangian model effectiveness for assessing emission sources contributions to the air pollution: particles tracking and accumulation estimate. The article describes model setting up parameters and datasets preparation for the analysis. The experiment simulated the dispersion from the main groups of emission sources for real weather conditions during 96 h of December 2018, when significant excess of NO2, CO, SO2, PM10, and benzo(a)pyrene concentrations were observed in the Krasnoyarsk surface atmospheric layer. The computational domain was a parallelepiped of 40 × 30 × 2.5 km, which was located deep inside the Eurasian continent on a heterogeneous landscape exaggerated by high-rise buildings, with various pollutions sources and the ice-free Yenisei River. The results demonstrated an excellent applicability of the Lagrange model for hourly tracking of particle trajectories, taking into account the urban landscape. For values <1 MPC (maximum permissible concentration) of peak pollutants concentrations, the coincidences were 93 cases, and for values < 0.1 shares of MPC, there were 36 cases out of the total number of 97. The same was found for the average daily concentration for values <1 MPC—31, and for values <0.1 MPC—5 matches out of 44. Wind speeds COR—65.3%, wind directions COR—68.6%. The Graz Lagrangian model showed the ability to simulate air quality problems in the Krasnoyarsk greater area conditions.

scholarly journals Shape-changing tensegrity-membrane building skin

2020 ◽  
Vol 310 ◽  
pp. 00046
Author(s):  
Lenka Kabošová ◽  
Eva Kormaníková ◽  
Stanislav Kmeť ◽  
Dušan Katunský
Keyword(s):  
Design Method ◽  
Global Climate ◽  
Weather Conditions ◽  
Building Envelope ◽  
Digital Design ◽  
Design Stage ◽  
Design Tools ◽  
Ambient Conditions ◽  
Weather Extremes ◽  
The Impact

Building skins are persistently exposed to changes in the weather, including the cases of weather extremes, increasing in frequency due to global climate change. As a consequence of the advancements of digital design tools, the integration of the weather conditions into the design process is much smoother. The impact of the ambient conditions on buildings and their structures can be digitally analyzed as early as in the conceptual design stage. These new design tools stimulate original ideas for shape-changing building skins, actively reacting to the dynamic weather conditions. In the paper, a digital design method is introduced, leading towards the design of a building skin, able of the passive shape adaptation when subjected to the wind. The designed building skin consists of a tensegrity structure where the tensioned elements are substituted by a tensile membrane, creating a self-equilibrated building skin element. In the previous research, a small prototype of this wind-adaptive element was created. The computer simulations are employed to predict the adaptive behavior of a bigger, full-scale building skin element. The before-mentioned building envelope becomes an active player in its surrounding environment, passively reacting to the wind in real-time, thanks to the geometric and material properties. Due to the local shape changes caused by the wind force, the wind can be perceived unconventionally through the adaptive building structure.

scholarly journals GF-5 Hyperspectral Data for Species Mapping of Mangrove in Mai Po, Hong Kong

2020 ◽  
Vol 12 (4) ◽  
pp. 656 ◽  
Author(s):  
Luoma Wan ◽  
Yinyi Lin ◽  
Hongsheng Zhang ◽  
Feng Wang ◽  
Mingfeng Liu ◽  
...  
Keyword(s):  
Hong Kong ◽  
Spectral Resolution ◽  
Hyperspectral Data ◽  
Support Vector ◽  
Species Discrimination ◽  
Infrared Range ◽  
Landsat 8 ◽  
Mangrove Species ◽  
Spectral Bands ◽  
Species Mapping

Hyperspectral data has been widely used in species discrimination of plants with rich spectral information in hundreds of spectral bands, while the availability of hyperspectral data has hindered its applications in many specific cases. The successful operation of the Chinese satellite, Gaofen-5 (GF-5), provides potentially promising new hyperspectral dataset with 330 spectral bands in visible and near infrared range. Therefore, there is much demand for assessing the effectiveness and superiority of GF-5 hyperspectral data in plants species mapping, particularly mangrove species mapping, to better support the efficient mangrove management. In this study, mangrove forest in Mai Po Nature Reserve (MPNR), Hong Kong was selected as the study area. Four dominant native mangrove species were investigated in this study according to the field surveys. Two machine learning methods, Random Forests and Support Vector Machines, were employed to classify mangrove species with Landsat 8, Simulated Hyperion and GF-5 data sets. The results showed that 97 more bands of GF-5 over Hyperion brought a higher over accuracy of 87.12%, in comparison with 86.82% from Hyperion and 73.89% from Landsat 8. The higher spectral resolution of 5 nm in GF-5 was identified as making the major contribution, especially for the mapping of Aegiceras corniculatum. Therefore, GF-5 is likely to improve the classification accuracy of mangrove species mapping via enhancing spectral resolution and thus has promising potential to improve mangrove monitoring at species level to support mangrove management.

scholarly journals Perceived impact of meteorological conditions on the use of public space in winter settlements

2020 ◽  
Vol 64 (4) ◽  
pp. 631-642
Author(s):  
Agneta Larsson ◽  
David Chapman
Keyword(s):  
Public Space ◽  
Online Survey ◽  
Ground Surface ◽  
Weather Conditions ◽  
Public Spaces ◽  
Meteorological Conditions ◽  
Ambient Conditions ◽  
Cross Sectional ◽  
Survey Responses ◽  
The Impact

AbstractThis study aimed to assess the impact of meteorological conditions on the use of public space in Scandinavia and Canada. Between September 21 and December 18, 2017, a cross-sectional online survey ‘EAMQ-Climate: space’ was distributed via web-based platforms. Survey responses were received from 361 residents (258 people from Scandinavia and 103 from Canada). The relative impact of the meteorological determinants on the use of public space was calculated, and a factor analysis was performed. Disparities between Canada and Scandinavia as well as between the climate zones represented were analysed using ANOVA. Overall results showed that the most significant meteorological enablers for the use of outdoor public spaces in winter were solar gain, snowfall and snow-covered surfaces. The main barriers were slush-covered and icy surfaces, rainfall and darkness. Wind and cold were conditions with less influence. The impact of rain and ice, however, differed between climatic zones. It was also established that, when addressing the meteorological impact on avoiding the use of public spaces in winter, it is vital to discriminate between conditions related to a) the ground surface and b) ambient conditions, as well as the particular significance of c) snow and sun, and d) darkness. For the design of public space in winter cities, we conclude that designers need to focus on a wider range of weather conditions than sun, wind and cold, and include snow, rainfall, slushy and icy ground and poor visibility. The study suggests that winter public space has a higher climatic design requirement to be successful than streets and pathways that are mainly used for soft mobility.

Optimization of InAs/GaSb superlattice pin photodiode design for the high temperature operation in the midwave infrared range

2012 ◽  
Author(s):  
P. Christol ◽  
R. Taalat ◽  
C. Maingue-Wilson ◽  
C. Cervera ◽  
H. Aït-Kaci ◽  
...  
Keyword(s):  
High Temperature ◽  
Infrared Range ◽  
Pin Photodiode ◽  
Midwave Infrared ◽  
High Temperature Operation

Design of Solar Assisted Community Biogas Plant

2009 ◽  
Author(s):  
Ankit Gupta
Keyword(s):  
Anaerobic Fermentation ◽  
Weather Conditions ◽  
Biogas Plant ◽  
Heat Transfer Fluid ◽  
Cold Weather ◽  
Ambient Conditions ◽  
Biogas Yield ◽  
Northern India ◽  
Collector System ◽  
Sufficient Energy

This study aims at providing a solution to the difficulty in the production of biogas in cold weather conditions especially during winters and in hilly regions where the temperature remains low throughout the year. As is well known biogas can be produced by anaerobic fermentation of organic materials with the help of bacteria [1]. Meynell [2] pointed out that the production of biogas becomes insignificant when the slurry temperature is less than 15°C. Such situations are usually faced in northern India, where the ambient temperature and, hence, the slurry temperature, in the winters drops below 15°C and hence improper digestion of slurry leads to poor biogas yield. This problem can be overcome by making the biogas plant solar assisted. The heat requirements of the digesters generally consist of three parts; (i) heat required for raising the temperature of incoming slurry for digestion; (ii) for compensating heat losses through the boundaries of the digester and (iii) for compensating losses that might occur in the piping between the heat source and the digester [3]. The required heat is provided from the collector which absorbs solar radiation and converts it into heat which is absorbed by a heat transfer fluid passing through the collector [4]. In this work, a biogas plant for a specified capacity has been designed. Based on the biogas plant dimensions and the average ambient conditions for a specified location, the rate of loss of energy was determined. A solar collector system has been designed to supply sufficient energy to maintain the slurry temperature of 35° C.

Sign in / Sign up

Export Citation Format

Share Document