1. Mathew M. Gunshor* 1, Scott Lindstrom 2, Timothy J. Schmit 3, David C. Tobin 1, W. Paul Menzel 1 1 Cooperative Institute for Meteorological Satellite Studies - University of Wisconsin; 2 Space Science & Engineering Center – University of Wisconsin; 3 NOAA/NESDIS/STAR/ASPB * mat.gunshor@ssec.wisc.edu Seventh Annual Symposium on Future Operational Environmental Satellite Systems – 2011 AMS Annual Meeting – 25-26 January 2011 – Seattle, WA INTERCALIBRATION ACTIVITIES AT CIMSS IN PREPARATION FOR THE GOES-R ERA Retrospective analysis of GOES vs AIRS will continue to cover GOES-9, -10, -11, - 12, and -13. The analysis will be expanded to cover international geostationary imagers such as FY-2 (China), MTSAT (Japan), and Meteosat (Europe). Acknowledgements The authors wish to thank the Space Science & Engineering Center (SSEC) Data Center at the University of Wisconsin for providing easy-to-use access to real-time and archived satellite data. The PEATE project is thanked for easy access to AIRS data. Additionally, Hal Woolf at CIMSS is to be thanked in memoriam for providing the US Standard Atmosphere spectrum and forward model software/transmittance coefficients; Jim Nelson at CIMSS is to be thanked for his assistance with various programming and scripting matters. Fangfang Yu is thanked for her assistance in getting the NESDIS version of the GSICS code operating at CIMSS. Fred Wu and Mitch Goldberg are thanked for their guidance and support. This work was supported under grant number: NA07EC0676. For more information about GSICS, visit the GSICS Coordination Center: http://www.star.nesdis.noaa.gov/smcd/GCC/index.php INTRODUCTION GSICS The GSICS Mission: Assure high-quality, inter-calibrated measurements from the international constellation of operational satellites to support the GEOSS goal of increasing the accuracy and interoperability of environmental products and applications for societal benefit. CIMSS is currently back-processing the entire GOES record overlapping with AIRS observations using the NOAA/NESDIS implementation of the GSICS algorithm. Purpose The purpose of intercalibration is to quantitatively relate the radiances from different sensors viewing the same target, which provides valuable information for a wide range of satellite activities. Intercalibration needed to improve the use of global observations for weather, climate and environmental applications. Supports the Global Space-based Inter-Calibration System (GSICS) goal to improve the use of space-based global observations for weather, climate and environmental applications Radiometric Accuracy AIRS calibration accuracy is believed to be within 0.1 K for most of the bands. Intercalibration Using AIRS Collocation. (Space; Time; Viewing Geometry) Transformation (Spectral Matching; Spatial Matching; Convert Radiances) High spectral resolution radiances are convolved with GEO spectral response functions. Filtering (Scene Uniformity; Day vs Night) Analysis METHOD Should Differences with AIRS be expected? Contributions to the difference can come from temporal, field of view size and shape, viewing angle differences and navigation differences as well as GEO spectral response function uncertainty; the latter of which is likely responsible for the largest sources of error. When AIRS radiances are convolved with GEO spectral response functions, any substantial gaps in the AIRS spectra creates some error. The magnitude of this error increases as the gaps in the AIRS spectral coverage increase and with more variable spectra. The error is small for some channels, such as the IRW, but large in others, such as the water vapor channels. A RETROSPECTIVE LOOK AT GOES-AIRS Near-Term Work GOES-10 Water Vapor Band (6.7  m) GOES-10 IR Window Band (11  m) GOES-10 “Dirty” Window Band (12  m) GOES-10 Shortwave Window Band (3.9  m) Select References Gunshor, Mathew M.; Schmit, Timothy J.; Menzel, W. Paul and Tobin, David C. Intercalibration of broadband geostationary imagers using AIRS. Journal of Atmospheric and Oceanic Technology, Volume 26, Issue 4, 2009, pp.746-758 Gunshor, M. M., T. J. Schmit, and W. P. Menzel, 2004: Intercalibration of the Infrared Window and Water Vapor Channels on Operational Geostationary Environmental Satellites Using a Single Polar Orbiting Satellite. J. Atmos. Oceanic Technol., 21, 61-68. Intercalibration in the GOES-R/JPSS Era Intercalibration activities will continue into the GOES-R/JPSS Era and beyond. GSICS and other methods will continue to be applied to the international suite of environmental satellite instruments These methods can be applied to GOES-R ABI and JPSS CrIS and VIIRS immediately following first data acquisition. Normal process for GOES Imagers includes a science-test phase of the post-launch test which includes radiometric assessment using intercalibration. CrIS is the Cross-track Infrared Sounder with spectral range consisting of 3 bands (LWIR is 650-1095 cm -1 ; MWIR is 1210-1750 cm -1 ; SWIR is 2155-2550 cm -1 ) with a 14km Nadir FOV. VIIRS is the Visible Infrared Imager Radiometer Suite with 9 Visible/Near IR bands, 8 Mid-Wave IR bands, and 4 Long-Wave IR bands. GEO = Geostationary Orbiting Instrument R AIRS  GEO = Radiance result of AIRS convolved with GEO SRF (mW/m 2 /ster/cm -1 ) R AIRS = AIRS Radiance (mW/m 2 /ster/cm -1 ) at wavenumber  (cm -1 ) SRF = Spectral Response Function  R = Radiance Difference (GEO-AIRS) Mean = Mean radiance for intercalibration scene T = Temperature (K) B -1 = Inverse Planck Function (Radiance to Brightness Temperature) AIRS Spectral Gaps AIRS Spectra Spectral Gaps Future Work GOESPeriod of Overlap with AIRS GOES-09Apr 2003 – Nov 2005 GOES-10Jan 2003 - Dec 2009 GOES-11Jul 2006 – Today GOES-12Apr 2003 – Today GOES-13Jun 2006–Jan 2007; Jul–Aug 2007; Aug 2008–Apr 2009; Jan 2010–Now GOES-14Jul 2009 – Jan 2010 (Test) GOES-15Mar 2010 – Oct 2010 (Test)