irsi > Infra-Red Sky ImagerInstrument Type(s) > Baseline • Guest

The infrared sky imager (IRSI) measures cloud fraction and precipitable water vapor. The IRSI captures hemispheric sky images and provide time series retrievals of fractional sky cover during both day and night. The instrument provides diurnal sky imagery in the mid-infrared atmospheric window and imagery during daylight hours in the visible wavelengths for cloud retrievals. The software automatically identifies cloudy and clear regions and calculates fractional sky cover.


  • Fixed
  • AMF1
  • AMF2
  • AMF3

Active Locations

Facility Name Start Date
Central Facility, Lamont, OK 2014-05-20


Morris VR. 2016. Infrared Sky Imager Instrument Handbook. Ed. by Robert Stafford, DOE ARM Climate Research Facility. DOE/SC-ARM-TR-182. 10.2172/1251421.


Reda I, J Konings, and Y Xie. 2015. "A method to measure the broadband longwave irradiance in the terrestrial direct solar beam." Journal of Atmospheric and Solar-Terrestrial Physics, 129(July 2015), 10.1016/j.jastp.2015.04.003.


Shaw JA and B Thurairajah. 2003. Short-term cloud statistics at NSA from the infrared cloud imager. In Proceedings of the Thirteenth Atmospheric Radiation Measurement (ARM) SCience Team Meeting, Ed. by D. Carrothers, Richland, WA: Department of Energy.

Shaw JA and B Thurairajah. 2003. Short-Term Cloud Statistics at NSA from the Infrared Cloud Imager. In Thirteenth Atmospheric Radiation Measurement (ARM) Program Science Team Meeting, Ed. by D. Carrothers, Richland, WA: U.S. Department of Energy.

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