Day/night whole sky imagers for 24-h cloud and sky assessment: history and overview

TitleDay/night whole sky imagers for 24-h cloud and sky assessment: history and overview
Publication TypeJournal Article
Year of Publication2013
AuthorsShields JE, Karr ME, Johnson RW, Burden AR
JournalApplied OpticsAppl. Opt.
Pagination1605 - 1616
Date Published2013/03
KeywordsAerosol and cloud effects; Atmospheric and oceanic optics; Atmospheric transmittance; Clouds; Multispectral and hyperspectral imaging; Remote sensing and sensors

A family of fully automated digital whole sky imagers (WSIs) has been developed at the Marine Physical Laboratory over many years, for a variety of research and military applications. The most advanced of these, the day/night whole sky imagers (D/N WSIs), acquire digital imagery of the full sky down to the horizon under all conditions from full sunlight to starlight. Cloud algorithms process the imagery to automatically detect the locations of cloud for both day and night. The instruments can provide absolute radiance distribution over the full radiance range from starlight through daylight. The WSIs were fielded in 1984, followed by the D/N WSIs in 1992. These many years of experience and development have resulted in very capable instruments and algorithms that remain unique. This article discusses the history of the development of the D/N WSIs, system design, algorithms, and data products. The paper cites many reports with more detailed technical documentation. Further details of calibration, day and night algorithms, and cloud free line-of-sight results will be discussed in future articles.

Short TitleAppl. Opt.
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