Whole Sky Imager (WSI)
Note: This instrument is currently inactive and/or retired.
Active Dates: 1/1/1993 to 1/12/2004
Instrument Categories: Cloud Properties
General Overview
The whole-sky imager (WSI) is an automated imager used for assessing and documenting cloud fields and cloud field dynamics. The WSI is a ground-based electronic imaging system that monitors the upper hemisphere. It is a passive, i.e., non-emissive, system that acquires images of the sky dome through three spectral filters (neutral, red, and blue). From these sky images, we can assess the presence, distribution, shape, and radiance of clouds over the entire sky using automated cloud decision algorithms and related processing. The current WSI model (EO System 6) is capable of image acquisition under daylight, moonlight, and starlight conditions.
Primary Measurements Taken
The following measurements are those considered scientifically relevant. Refer to the netCDF File Header Descriptions (Data Object Design Files) for the list of all available measurements, including those recorded for diagnostic or quality assurance purposes.
Available Value-Added Products
This instrument is an input to the following value-added products, which provide improved measurements or derived quantities.
- wsicloud - WSI: derived, cloud numbers, area, perimeter, & more
- wsicloudden - WSI: stationary (JPEG) images based on optical density retrieval
- wsicloudspec - WSI: stationary (JPEG) images based on spectral retrieval
- wsicloudsummary - WSI: cloud and aerosol info, classification summary data
- wsicloudsummarygif - WSI: images (GIF) relating to cloud, aerosol summary data
- wsifilesummary - WSI: images (GIF) and text representations of data existence
Available Datastreams
- 02wsipartradiance - WSI: calibrated red or clear images and house keeping data, 2-min intervals
- 02wsipartradjpg - WSI: stationary calibrated red or clear quicklook images (JPEG), 2-min intervals
- 02wsipartradmpg - WSI: calibrated red or clear quicklook movies (MPEG), 2-min intervals
- 10wsipartradjpg - WSI: stationary calibrated red or clear quicklook images (JPEG), 10 min intervals
- 10wsipartradmpg - WSI: calibrated red or clear quicklook movies (MPEG), 10 min intervals
- wsifullradiance - WSI: calibrated radiances for each pixel, with multiple filters
- wsipatchsummary - WSI: radiances from red image for three patches (avg and SD)
Sites / Facilities
Note: Click the "
" to expand/collapse the list.
- North Slope Alaska (NSA)
- Central Facility, Atqasuk AK (C2)
- Central Facility, Barrow AK (C1)
- Southern Great Plains (SGP)
- Blackwell/Tonkawa Airport, OK (L3)
- Central Facility, Lamont, OK (C1)
- Tropical Western Pacific (TWP)
- Central Facility, Darwin, North Australia (C3)
- Central Facility, Manus I., PNG (C1)
- Central Facility, Nauru Island (C2)
Mentor(s)
Jimmy Voyles
(979) 690-9846
jimmy.voyles@pnl.gov
