scholarly journals Day and Night Clouds Detection Using a Thermal-Infrared All-Sky-View Camera

2021 ◽  
Vol 13 (9) ◽  
pp. 1852
Author(s):  
Yiren Wang ◽  
Dong Liu ◽  
Wanyi Xie ◽  
Ming Yang ◽  
Zhenyu Gao ◽  
...  
Keyword(s):  
Infrared Image ◽  
Thermal Infrared ◽  
Field Of View ◽  
Detection Scheme ◽  
Detection Approach ◽  
Cloud Characteristics ◽  
Formation And Evolution ◽  
Fish Eye ◽  
Infrared Channel

The formation and evolution of clouds are associated with their thermodynamical and microphysical progress. Previous studies have been conducted to collect images using ground-based cloud observation equipment to provide important cloud characteristics information. However, most of this equipment cannot perform continuous observations during the day and night, and their field of view (FOV) is also limited. To address these issues, this work proposes a day and night clouds detection approach integrated into a self-made thermal-infrared (TIR) all-sky-view camera. The TIR camera consists of a high-resolution thermal microbolometer array and a fish-eye lens with a FOV larger than 160°. In addition, a detection scheme was designed to directly subtract the contamination of the atmospheric TIR emission from the entire infrared image of such a large FOV, which was used for cloud recognition. The performance of this scheme was validated by comparing the cloud fractions retrieved from the infrared channel with those from the visible channel and manual observation. The results indicated that the current instrument could obtain accurate cloud fraction from the observed infrared image, and the TIR all-sky-view camera developed in this work exhibits good feasibility for long-term and continuous cloud observation.

Apparent Temperature Patterns Superposed on Thermal Infrared Images and Their Removal

1996 ◽  
Vol 8 (2) ◽  
pp. 136-143
Author(s):  
Minoru Inamura ◽  
Keyword(s):  
Infrared Image ◽  
Radiation Energy ◽  
Thermal Infrared ◽  
Absolute Temperature ◽  
Field Of View ◽  
Apparent Temperature ◽  
Large Field ◽  
True Temperature ◽  
Temperature Pattern ◽  
Effective Use

A thermal infrared image is a visualized image of the thermal energy radiated from an object. Thermal radiation energy is dependent on the absolute temperature and the effective emissivity of an object, so that a thermal infrared image does not give the temperature distribution of an object but, rather, is a superimposed image of, so to speak, the temperature pattern and the emissivity pattern. In other words, a emissivity pattern is an apparent temperature pattern superimposed on a true temperature pattern. However, this paper points out that a thermal infrared image obtained with a sensor having an instantaneously large field of view, like a remotely sensed image, has additionally a third pattern due to the size of the field of view superimposed and that this appears as an apparent temperature change on the thermal infrared image. Moreover, the paper stresses the fact that in order to obtain correct information on temperature, it is necessary to remove these patterns and, at the same time, points out that these can be removed if effective use is made of visible, multispectral images.

scholarly journals Publisher Correction: Miniature two-photon microscopy for enlarged field-of-view, multi-plane and long-term brain imaging

2021 ◽  
Vol 18 (2) ◽  
pp. 220-220
Author(s):  
Weijian Zong ◽  
Runlong Wu ◽  
Shiyuan Chen ◽  
Junjie Wu ◽  
Hanbin Wang ◽  
...  
Keyword(s):  
Brain Imaging ◽  
Field Of View ◽  
Two Photon Microscopy ◽  
Two Photon

scholarly journals R Coronae Borealis Stars: Long-Term Photometric & Spectroscopic Studies

1998 ◽  
Vol 11 (1) ◽  
pp. 379-379
Author(s):  
P.L. Cottrell ◽  
L. Skuljan ◽  
P.M. Kilmartin ◽  
C. Gilmore ◽  
W.A. Lawson
Keyword(s):  
Radial Velocity ◽  
Spectroscopic Studies ◽  
Photometric Data ◽  
Decline Phase ◽  
Dust Clouds ◽  
Medium Resolution ◽  
Formation And Evolution ◽  
R Coronae Borealis Stars ◽  
Insight Into

For more than a decade we have been able to acquire and analyse a significant amount of photometric data of the highly variable R Coronae Borealis (RCB) stars. This has made been possible by a photometric service observing programme instigated at the Observatory. These photometric data have been combined with less extensive spectroscopic coverage, particularly of the decline phase of these stars. These have been supplemented by observations obtained at Mount Stromlo and Siding Spring Observatories for a radial velocity study. Significantly more spectroscopic observations are now being acquired with the development of a new medium resolution spectrograph at Mount John University Observatory. In this poster we will present recent photometric and spectroscopic results for a number of the RCB stars in our sample. This observational and analysis work can be used to provide further insight into the nature of these stars, their likely progeny and progenitors and the processes that are involved in the formation and evolution of the obscuring dust clouds which cause the decline phase.

Calibration of Landsat 5 thermal infrared channel: updated calibration history and assessment of the errors associated with the methodology

2010 ◽  
Vol 36 (5) ◽  
pp. 617-630 ◽  
Author(s):  
Francis P. Padula ◽  
John R. Schott ◽  
Julia A. Barsi ◽  
Nina G. Raqueno ◽  
Simon J. Hook
Keyword(s):  
Thermal Infrared ◽  
Infrared Channel

scholarly journals Comprehensive Detection, Grading, and Growth Behavior Evaluation of Subthreshold and Low Intensity Photocoagulation Lesions by Optical Coherence Tomographic and Infrared Image Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Stefan Koinzer ◽  
Amke Caliebe ◽  
Lea Portz ◽  
Mark Saeger ◽  
Yoko Miura ◽  
...  
Keyword(s):  
Treatment Efficacy ◽  
Clinical Effect ◽  
Infrared Image ◽  
Growth Behavior ◽  
Retinal Damage ◽  
Optical Coherence ◽  
Retinal Area ◽  
Low Intensity ◽  
Irradiation Power

Purpose. To correlate the long-term clinical effect of photocoagulation lesions after 6 months, as measured by their retinal damage size, to exposure parameters. We used optical coherence tomographic (OCT)-based lesion classes in order to detect and assess clinically invisible and mild lesions.Methods. In this prospective study, 488 photocoagulation lesions were imaged in 20 patients. We varied irradiation diameters (100/300 µm), exposure-times (20–200 ms), and power. Intensities were classified in OCT images after one hour, and we evaluated OCT and infrared (IR) images over six months after exposure.Results. For six consecutive OCT-based lesion classes, the following parameters increased with the class: ophthalmoscopic, OCT and IR visibility rate, fundus and OCT diameter, and IR area, but not irradiation power. OCT diameters correlated with exposure-time, irradiation diameter, and OCT class. OCT classes discriminated the largest bandwidth of OCT diameters.Conclusion. OCT classes represent objective and valid endpoints of photocoagulation intensity even for “subthreshold” intensities. They are suitable to calculate the treated retinal area. As the area is critical for treatment efficacy, OCT classes are useful to define treatment intensity, calculate necessary lesion numbers, and universally categorize lesions in clinical studies.

scholarly journals A Thermal Infrared and Visible Images Fusion Based Approach for Multitarget Detection under Complex Environment

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Xinnan Fan ◽  
Pengfei Shi ◽  
Jianjun Ni ◽  
Min Li
Keyword(s):  
Thermal Infrared ◽  
Basic Belief ◽  
Measured Signal ◽  
Complex Environment ◽  
Distance Distribution Function ◽  
Detection Approach ◽  
Efficiency And Effectiveness ◽  
Visible Images ◽  
Belief Theory ◽  
Update Process

Multitarget detection under complex environment is a challenging task, where the measured signal will be submerged by noise. D-S belief theory is an effective approach in dealing with Multitarget detection. However, there are some limitations of the general D-S belief theory under complex environment. For example, the basic belief assignment is difficult to establish, and the subjective factors will influence the update process of evidence. In this paper, a new Multitarget detection approach based on thermal infrared and visible images fusion is proposed. To easily characterize the defected heterogeneous image, a basic belief assignment based on the distance distribution function of heterogeneous characteristics is presented. Furthermore, to improve the discrimination and effectiveness of the Multitarget detection, a concept of comprehensive credibility is introduced into the proposed approach and a new update rule of evidence is designed. Finally, some experiments are carried out and the experimental results show the efficiency and effectiveness of the proposed approach in the Multitarget detection task.

Retrieval of the pixel component temperatures from multi-band thermal infrared image using Bayesian inversion technique

2016 ◽  
Author(s):  
Feng Xie ◽  
Honglan Shao ◽  
Zhihui Liu ◽  
Chengyu Liu ◽  
Changxing Zhang ◽  
...  
Keyword(s):  
Infrared Image ◽  
Thermal Infrared ◽  
Bayesian Inversion ◽  
Inversion Technique ◽  
Multi Band
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