Spectral characteristics of infrared radiation from forest fires

Author(s):  
Han Sun ◽  
Zhiguo Rong ◽  
Cheng Liu ◽  
Jingjing Liu ◽  
Yan Zhang ◽  
...  
2018 ◽  
Vol 5 (12) ◽  
pp. 180787
Author(s):  
Liang Furong ◽  
Liu Weijun ◽  
Han Xiuxiu ◽  
Zhang Boru ◽  
Zhang Shuhua

Taking potassium hexatitanate whisker (PTW) modified by silane coupling agent KH550, aluminium nitrate inorganic salt and tetraethyl orthosilicate and deionized water, respectively, as infrared sunscreen, aluminium source and raw materials forming the network structure of a composite xerogel, a series of structurally intact PTW-doped Al 2 O 3 –SiO 2 composite xerogel thermal-insulating materials were prepared by the sol–gel method and dried under atmospheric pressure. The infrared spectral characteristics, infrared radiation transmittance, microstructures, morphology and thermal conductivity of different composite materials prepared have been determined by a Fourier transform infrared spectrometer, UV–visible–near-infrared spectrophotometer, X-ray diffractometer, scanning electron microscope and thermal conductivity tester. The results exhibit that when the Al to Si molar ratio is 1 : 9, the composite material with 5 wt% modified PTW shows the best infrared radiation blocking performance and the lowest thermal conductivity (0.0604 W m −1 K −1 ).


2008 ◽  
Vol 144 ◽  
pp. 226-231 ◽  
Author(s):  
Jitka Mohelníková

Glasses reflective in the spectral range of long-wave infrared radiation operate as heat mirrors. These glasses have found wide applications in architecture. Special thin film coatings on glass panes reflect long wave infrared radiation back to building interiors. The reflective thin films limit absorption of infrared radiation within the glass pane and reduce radiation heat losses of glazings. Heat losses of windows could be significantly limited with the coated glasses which are called low-emissivity glazings. The study of materials convenient for infrared reflective coatings, the optimal composition of thin films and their thicknesses is the main topic of the presented paper. The study is based on measurements of spectral characteristics of selected glasses and computer simulations of the thin film composition for applications of window infrared reflective coatings.


2021 ◽  
Vol 13 (7) ◽  
pp. 1345
Author(s):  
Admilson da Penha Pacheco ◽  
Juarez Antonio da Silva Junior ◽  
Antonio Miguel Ruiz-Armenteros ◽  
Renato Filipe Faria Henriques

Forest fires threaten the population's health, biomass, and biodiversity, intensifying the desertification processes and causing temporary damage to conservation areas. Remote sensing has been used to detect, map, and monitor areas that are affected by forest fires due to the fact that the different areas burned by a fire have similar spectral characteristics. This study analyzes the performance of the k-Nearest Neighbor (kNN) and Random Forest (RF) classifiers for the classification of an area that is affected by fires in central Portugal. For that, image data from Landsat-8, Sentinel-2, and Terra satellites and the peculiarities of each of these platforms with the support of Jeffries–Matusita (JM) separability statistics were analyzed. The event under study was a 93.40 km2 fire that occurred on 20 July 2019 and was located in the districts of Santarém and Castelo Branco. The results showed that the problems of spectral mixing, registration date, and those associated with the spatial resolution of the sensors were the main factors that led to commission errors with variation between 1% and 15.7% and omission errors between 8.8% and 20%. The classifiers, which performed well, were assessed using the receiver operating characteristic (ROC) curve method, generating maps that were compared based on the areas under the curves (AUC). All of the AUC were greater than 0.88 and the Overall Accuracy (OA) ranged from 89 to 93%. The classification methods that were based on the kNN and RF algorithms showed satisfactory results.


1980 ◽  
Vol 112 (2) ◽  
pp. 211-216 ◽  
Author(s):  
W. G. Evans ◽  
J. E. Kuster

AbstractReceptive fields of the infrared receptors located in sensory pits adjacent to the mesocoxal cavities of Melanophila acuminata were measured using a goniometric apparatus and plotted on a Mollweide homolographic projection. The receptive fields extend mainly in a lateral and ventral direction. The total receptive area in units of solid angle is 5.80 steradians but the simultaneous field of perception of infrared radiation of all the sensilla in a pit is only 0.42 steradian. Based on these findings and on other evidence we believe that the infrared-sensitive sensilla function during flight and are used by these beetles for detecting point sources of heat, such as forest fires, from long distances.


Sign in / Sign up

Export Citation Format

Share Document