USDA reference UV spectroradiometric network: Current performance and operational experience

At present the USDA Reference Spectroradiometric Network consists of 3 sites: Table Mt. CO, Lamont OK (the ARM program SGP site), and Beltsville MD. At each site we deploy and continuously operate a 1-meter cascaded additive-double Czerny-Turner scanning monochromator with a bi-alkali Photomultiplier and photon-counting detection. Lambertian fore-optic errors are less than 1% over the range of zenith angles from 0 to 80 degrees. The instruments use photon counting and make measurements not affected by stray light at 290 nm under typical conditions. The basic performance specifications of the instrument were demonstrated by a prototype at the 1997 North American UV Spectroradiometer Intercomparison. Data shown here demonstrate that these are met in routine operation.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.