The 1997 North American Interagency Intercomparison of Ultraviolet Spectroradiometers Including Narrowband Filter Radiometers

Published

January 1, 2002

Author(s)

K Lantz, P Disterhoft, E A. Early, Ambler Thompson, J DeLuisi, J Berndt, L Harrison, P Kiedron, J Ehramjian, G Bernhard, L Cabasug, JL Robertson, W Mou, T Taylor, J Slusser, D Bigelow, B Durham, G Janson, D Hayes, M Beaubien, A Beaubien

Abstract

The fourth North American Intercomparison of Ultraviolet Monitoring Spectroradiometers was held September 15 to 25, 1997 at Table Mountain outside of Boulder, Colorado, USA. Concern over stratospheric ozone depletion has prompted several government agencies in North America to establish networks of spectrooradiometers for monitoring solar ultraviolet irradiance at the surface of the Earth. The main purpose of the Intercomparison was to assess the ability of spectroradiometers to accurately measure solar ultraviolet irradiance, and to compare the results between instruments of different monitoring networks. This Intercomparison was coordinated by NIST and NOAA, and included participants from the ASRC, EPA, NIST, NSF, SERC, USDA and YES. The UV measuring instruments included scanning spectroradiometers, spectrographs, narrow band multi-filter radiometers, and broadband radiometers. Instruments were characterized for wavelength accuracy, bandwidth, stray-light rejection, and spectral irradiance responsivity, the latter with NOAA standard lamps calibrated to operate in the horizontal position. The spectral irradiance responsivity was determined two to three times outdoors to assess temporal stability. Synchronized spectral scans of the solar irradiance were performed over several days. Using the spectral irradiance responsivities determined with the NIST traceable standard lamp, and a simple convolution technique with a Gaussian slit-scattering function to account for the different bandwidths of the instruments, the measured solar irradiance from the spectroradiometers excluding the filter radiometers at 16.5 UTC had a relative standard deviation of 4% for wavelengths greater than 305 nm. The relative standard deviation for the solar irradiance at 16.5 UTC including the filter was 4% for filter functions above 300 nm.

Citation

Journal of Research (NIST JRES) -

Volume

107 No. 1

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

Keywords

environmental monitoring, intercomparison, solar ultraviolet, spectroradiometers

Citation

Lantz, K. , Disterhoft, P. , Early, E. , Thompson, A. , DeLuisi, J. , Berndt, J. , Harrison, L. , Kiedron, P. , Ehramjian, J. , Bernhard, G. , Cabasug, L. , Robertson, J. , Mou, W. , Taylor, T. , Slusser, J. , Bigelow, D. , Durham, B. , Janson, G. , Hayes, D. , Beaubien, M. and Beaubien, A. (2002), The 1997 North American Interagency Intercomparison of Ultraviolet Spectroradiometers Including Narrowband Filter Radiometers, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD (Accessed May 3, 2024)