Abstract
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.
Highlights
(5), as well as the statistical characteristics of the gray value of the infrared raw sky image, we propose a clear-sky emission value of the model infrared raw on skythe image
The cloud fractions of the infrared images have a good correlation with visible and manual observations, there are still discrete points that deviate from the 1:1 line
A TIR all-sky-view camera and clouds discrimination algorithm was developed for infrared cloud fraction estimation
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Devices working in this spectral band can directly detect the TIR emission of both clouds and the atmosphere, excluding the scattered light of the sun or starlight This category of cloud observation instruments, for example, the infrared clouds imager (ICI), can identify the clouds and estimate the cloud fraction during the day and night [25]. The whole sky image splicing process occupies additional computer resources and is time-consuming To address these issues, an instrument using a TIR all-sky-view camera for long-term and continuous cloud observation is developed in this work. An instrument using a TIR all-sky-view camera for long-term and continuous cloud observation is developed in this work This instrument consists of a TIR microbolometer array and a germanium lens, which can obtain infrared sky images with a FOV greater than 160◦.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
