title: Radiometric Measurement Comparison on the Integrating Sphere Source Used to Calibrate the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Landsat 7 Enhanced Thematic Mapper Plus (ETM+).
abstract: As part of a continuing effort to validate the radiometric scales assigned to integrating sphere sources used in the calibration of Earth Observing System (EOS) instruments, a radiometric measurement comparison was held in May 1998 at Raytheon/Santa Barbara Remote Sensing (SBRS). This comparison was conducted in support of the calibration of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) instruments. The radiometric scale assigned to the Spherical Integrating Source (SIS100) by SBRS was validated through a comparison with radiometric measurements made by a number of stable, well-characterized transfer radiometers from the National Institute of Standards and Technology (NIST), the National Aeronautics and Space Administration's Goddard Space Flight Center (NASA's GSFC), and the University of Arizona Optical Sciences Center (UA). The measured radiances from the radiometers differed by ±3 % in the visible to near infrared when compared to the SBRS calibration of the sphere, and the overall agreement was within the combined uncertainties of the individual measurements. In general, the transfer radiometers gave higher values than the SBRS calibration in the near infrared and lower values in the blue. The measurements of the radiometers differed by ±4 % from 800 nm to 1800 nm compared to the SBRS calibration of the sphere, and the overall agreement was within the combined uncertainties of the individual measurements for wavelengths less than 2200 nm. The results of the radiometric measurement comparison presented here supplement the results of previous measurement comparisons on the integrating sphere sources used to calibrate the Multi-angle Imaging SpectroRadiometer (MISR) at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) at NEC Corporation, Yokohama, Japan.
authors.affiliation: Laboratory for Terrestrial Physics, National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, MD 20771.
authors.forename: James J
authors.initials: JJ
authors.lastname: Butler
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Brown
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Saunders
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
authors.forename: B Carol
authors.initials: BC
authors.lastname: Johnson
authors.affiliation: Remote Sensing Group, Optical Sciences Center, University of Arizona, Tucson, AZ 85721.
authors.forename: Stuart F
authors.initials: SF
authors.lastname: Biggar
authors.affiliation: Remote Sensing Group, Optical Sciences Center, University of Arizona, Tucson, AZ 85721.
authors.forename: Edward F
authors.initials: EF
authors.lastname: Zalewski
authors.affiliation: Laboratory for Terrestrial Physics, National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, MD 20771.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Markham
authors.affiliation: Raytheon Santa Barbara Remote Sensing, Goleta, CA 93117.
authors.forename: Paul N
authors.initials: PN
authors.lastname: Gracey
authors.affiliation: Raytheon Santa Barbara Remote Sensing, Goleta, CA 93117.
authors.forename: James B
authors.initials: JB
authors.lastname: Young
authors.affiliation: Science Applications International Corporation, Beltsville, MD 20705.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Barnes
keywords: Earth Observing System (EOS); Landsat 7 Enhanced Thematic Mapper Plus (ETM+); Moderate Resolution Imaging Spectroradiometer (MODIS); calibration; integrating sphere; remote sensing; spectral radiometry; transfer radiometers