525 Hits in 8.8 sec

Light Transmission in Fog: The Influence of Wavelength on the Extinction Coefficient

Pierre Duthon, Michèle Colomb, Frédéric Bernardin
2019 Applied Sciences  
The influence of wavelength on light transmission in fog is then examined and results reported.  ...  A theoretical approach by calculating the extinction coefficient for different wavelengths is presented in comparison to measurements with a spectroradiometer in the range of 350 nm–2450 nm.  ...  According to that study, the most useful wavelength in fog conditions is 690 nm. However, this study was based solely on modeling, and there was no experimental confirmation of the results presented.  ... 
doi:10.3390/app9142843 fatcat:75fqjcupxvfv7ppgtxpi6jem6e

Experimental Study of the Effects of Environmental and Fog Condensation Nuclei Parameters on the Rate of Fog Formation and Dissipation Using a New Laboratory Scale Fog Generation Facility

Vivek Pratap Singh, Tarun Gupta, Sachchida Nand Tripathi, Chinmay Jariwala, Utpal Das
2011 Aerosol and Air Quality Research  
Direct comparisons were made for theoretical droplet growth and settling times in predicting the period for which stable fog was expected Vs the actual experimentally measured times for stable fog generated  ...  The IIT Kanpur Fog Chamber Facility has been conceptualized and built indigenously to study the fog formation and dissipation under various environmental conditions.  ...  ACKNOWLEDGMENTS We acknowledge the financial support provided by Technology mission on Railway Safety (TMRS) Ministry of Railway and Ministry of Human Resource Development, Govt. of India and ICRS programme  ... 
doi:10.4209/aaqr.2010.08.0071 fatcat:phezzcfaujcqddv7tyjgy5rmbe

Nighttime Visibility Analysis and Estimation Method in the Presence of Dense Fog

Romain Gallen, Aurelien Cord, Nicolas Hautiere, Eric Dumont, Didier Aubert
2015 IEEE transactions on intelligent transportation systems (Print)  
A methodology to detect the presence of night fog and characterize its density in images grabbed by an in-vehicle camera is then proposed.  ...  If fog is detected, its characterization is achieved by fitting the different correlation indexes with an empirical model. Experimental results show the efficiency of the proposed method.  ...  Using spectral features and a simple linear classifier, a classification of images in fog and fog-free scenes is proposed in [15] .  ... 
doi:10.1109/tits.2014.2331177 fatcat:asidgetmsvb57kvixwazmxrhq4

Fog Classification by Their Droplet Size Distributions: Application to the Characterization of Cerema's Platform

Pierre Duthon, Michèle Colomb, Frédéric Bernardin
2020 Atmosphere  
This study presents an original method for classifying these different types of fog in a descriptive and quantitative way.  ...  As fog conditions are random and non-reproducible in nature, Cerema has designed a platform to generate fog and rain on demand.  ...  The use of the most common fog models in the literature provided a third source of comparison. Given the PSA used and the natural data available to us, this study focused on radiation fogs only.  ... 
doi:10.3390/atmos11060596 fatcat:3rhgzcdttbgt3cyxwrkdtyxpfy

Visibility Enhancement and Fog Detection: Solutions Presented in Recent Scientific Papers with Potential for Application to Mobile Systems

Răzvan-Cătălin Miclea, Vlad-Ilie Ungureanu, Florin-Daniel Sandru, Ioan Silea
2021 Sensors  
In addition to the visibility problem, the driver must face also the choice of speed while driving. The main effects of fog are a decrease in contrast and a fade of color.  ...  It is useful to focus on what has been presented in the scientific literature over the past ten years relative to these concerns.  ...  He studied the luminance attenuation in the atmosphere and proposed a law relating to the apparent contrast of an object against a sky background.  ... 
doi:10.3390/s21103370 pmid:34066176 fatcat:owkgxijv2bccjn2y3vzoxw2hka

Numerical Simulation of Condensation of Natural Fog Aerosol under Acoustic Wave Action

Chang Liu, Yun Zhao, Zhangfu Tian, Hefeng Zhou
2020 Aerosol and Air Quality Research  
Traditional artificial fog dissipation can be divided into two specific 33 operations: artificial warm fog dissipation and artificial cool fog dissipation (Gao et al., 2010). 34 However, the traditional  ...  In 1936, the Faraday Society in London held a meeting to study the feasibility of 42 using sound waves for fog removal.  ...  mechanism, acoustic wake effect mechanism) and gravity sedimentation mechanism 382 into the model, which was found to be in good agreement with the experimental results; In 2019, 383 Zheng and Wang  ... 
doi:10.4209/aaqr.2020.06.0361 fatcat:pnfddvktcrg6fjs7b3cbrrcqsa

Droplet activation behaviour of atmospheric black carbon particles in fog as a function of their size and mixing state

Ghislain Motos, Julia Schmale, Joel C. Corbin, Marco Zanatta, Urs Baltensperger, Martin Gysel-Beer
2019 Atmospheric Chemistry and Physics  
and their activation to form droplets in fog.  ...  in a consistent manner in model simulations.  ...  We would like to thank the University of Zurich for providing access to the Irchel campus as a measurement site and the group led by Ulrike Lohmann ETH Zurich for lending us a CCNC.  ... 
doi:10.5194/acp-19-2183-2019 fatcat:hvu6j5in5rghze6opdwosjn4ne

Terahertz wireless communications [chapter]

J.F. Federici, L. Moeller, K. Su
2013 Handbook of Terahertz Technology for Imaging, Sensing and Communications  
Since weather conditions such as fog and dust exhibit a spectral dependence in the atmospheric attenuation, the corresponding impact on THz in comparison with IR communications is not equivalent.  ...  Mie scattering theory was used to study the attenuation of THz and IR radiation due to the dust particle.  ...  airborne particulates (fog and dust ), and experimental scintillation effects study of IR links.  ... 
doi:10.1533/9780857096494.1.156 fatcat:2qzfaetnufeztbtx4rb5bwtaau

Full waveform LiDAR for adverse weather conditions

Andrew M Wallace, Abderrahim Halimi, Gerald S Buller
2020 IEEE Transactions on Vehicular Technology  
We report several experimental studies on LiDAR imaging through complex media, and how these can inform the automotive LiDAR scenario.  ...  We present and discuss the case for full waveform pixel and image acquisition and processing to enable LiDAR sensors to penetrate and reconstruct 3D surface maps through obscuring media.  ...  Fig. 3 . 3 A comparison of attenuation loss in Fog and Smoke in the visible and near infrared Fig. 4 . 4 Comparison of attenuation coefficient of glycol-based smoke at visible and 1550 nm wavelengths  ... 
doi:10.1109/tvt.2020.2989148 fatcat:inmf3tm75nh4db5i2mzyhidzga

VisNet: Deep Convolutional Neural Networks for Forecasting Atmospheric Visibility

Akmaljon Palvanov, Young Cho
2019 Sensors  
Prior to feeding the network, each input image is filtered in the frequency domain to remove low-level features, and a spectral filter is applied to each input for the extraction of low-contrast regions  ...  In addition, we have collected the largest dataset with three million outdoor images and exact visibility values for this study.  ...  We provide experimental results and benchmarks on previously used models, including the state-of-the-art comparison.  ... 
doi:10.3390/s19061343 fatcat:imdovjvezfcjvhlz6mk2gytoqy

Simultaneous underwater visibility assessment, enhancement and improved stereo

Martin Roser, Matthew Dunbabin, Andreas Geiger
2014 2014 IEEE International Conference on Robotics and Automation (ICRA)  
The technique estimates the visibility properties from a sparse 3D map of the original degraded image using a physical underwater light attenuation model.  ...  Secondly, using a light attenuation model for ocean water, a color corrected stereo underwater image is obtained along with a visibility distance estimate.  ...  Whilst no literature on underwater stereo visibility enhancement has been found, some studies have considered it for seeing through fog [15] - [17] .  ... 
doi:10.1109/icra.2014.6907416 dblp:conf/icra/RoserDG14 fatcat:qnde2uympjdoximhxjb3jewgdi

The Perception System of Intelligent Ground Vehicles in All Weather Conditions: A Systematic Literature Review

Abdul Sajeed Mohammed, Ali Amamou, Follivi Kloutse Ayevide, Sousso Kelouwani, Kodjo Agbossou, Nadjet Zioui
2020 Sensors  
Every year, the loss in visibility due to snow, fog, and rain causes serious accidents worldwide.  ...  The goal of this paper is to provide a survey of sensing technologies used to detect the surrounding environment and obstacles during driving maneuvers in different weather conditions.  ...  In [190] , a brief comparison in detection, classification, and recognition tasks in a normal and closed fog chamber with various vision spectral bands, such as visible (RGB), nearinfrared (NIR), short-wave  ... 
doi:10.3390/s20226532 pmid:33203155 fatcat:tdorifxpznamlfvgl64wmkjlpu

Optical Communication in Space: Challenges and Mitigation Techniques

Hemani Kaushal, Georges Kaddoum
2017 IEEE Communications Surveys and Tutorials  
power and low mass requirements.  ...  This survey provides the reader with comprehensive details on the use of space-based optical backhaul links in order to provide high-capacity and low-cost backhaul solutions.  ...  A comparison of fog attenuation properties for different operating wavelengths is studied in [90] . The attenuation due to fog can be predicted by applying Mie scattering theory.  ... 
doi:10.1109/comst.2016.2603518 fatcat:zv3fa7k2pbet3pi6gphq6izqae

Autonomous Driving in Adverse Weather Conditions: A Survey [article]

Yuxiao Zhang, Alexander Carballo, Hanting Yang, Kazuya Takeda
2021 arXiv   pre-print
This paper assesses the influences and challenges that weather brings to ADS sensors in an analytic and statistical way, and surveys the solutions against inclement weather conditions.  ...  External auxiliary solutions like V2X technology, weather conditions coverage in currently available datasets, simulators, and experimental facilities with weather chambers are distinctly sorted out.  ...  “Experimental study on ots/outdoor/your-perfect-palette/. low-THz automotive radar signal attenuation dur- [113] Shaopeng Ma, Shichao Zhou, and Qinwei Ma.  ... 
arXiv:2112.08936v1 fatcat:hmgjhywy7rgx3fgrk6yxnu56ie

Real-time rendering of aerial perspective effect based on turbidity estimation

Carlos Morales, Takeshi Oishi, Katsushi Ikeuchi
2017 IPSJ Transactions on Computer Vision and Applications  
In those cases, even state-of-the-art models fail to generate realistic synthesized aerial perspective effects.  ...  challenging in terms of visual coherence and computational cost.  ...  Acknowledgements This work was, in part, supported by JSPS KAKENHI Grant Number 16H05864.  ... 
doi:10.1186/s41074-016-0012-1 fatcat:5466ftfnybfx3k2bgkucinh4hu
« Previous Showing results 1 — 15 out of 525 results