NOAA Office of Satellite and Product Operations

GOES-8 through GOES-15 Imager Spectral Response Functions

(Revised, August 2011)

The latest versions of GOES-8 through GOES-15 Imager spectral response functions (SRFs) are available for download. All of them were provided by ITT (the instruments' manufacturer), except those noted as modified by STAR.

Imager spectral response function download table
GOES-8 Sounder Operational SRFs  
GOES-9 Sounder Operational SRFs  
GOES-10 Sounder Operational SRFs  
GOES-11 Sounder Currently operational SRFs  
GOES-12 Sounder Currently operational SRFs  
GOES-13 Sounder Currently operational SRFs  
GOES-14 Sounder Currently operational SRFs
(ITT Release RevH;: 2011 plus STAR Correction)
Discontinued Aug. 9, 2011
(Release Rev E1; 2008)
Discontinued on Nov. 24, 2009
(Release Rev D; 2005)
GOES-15 Sounder Currently operational SRFs
(ITT Release RevH;: 2011 plus STAR Correction)
Discontinued on August 9, 2011
(Release Rev E; 2008)

1 Note: The GOES-13,14,15 Imager SRFs are the same in ITT releases Rev. E, 2008 and Rev. F, 2010.

GOES-13 Imager History

Note that three versions of the spectral response functions (SRFs) for channel 6 (13.3 microns central wavelength) of the GOES-13 Imager are presented within the links and tables on this website, along with the related calibration parameters associated with each SRF version. These different SRFs have come about due to the identification of a cold bias in the brightness temperatures of the channel 6 images before GOES-13 went into operation as GOES-EAST.

Version 1: Original (Release Rev.D, 2005)
The original channel 6 SRFs provided by the instrument vendor, ITT, were used during the GOES-13 post-launch tests in 2006 when a cold bias of -2.4±0.6 K in the channel 6 imagery was reported by the CIMSS group at University of Wisconsin. The cold bias was identified via comparisons with high spectral resolution Atmospheric InfraRed Sounder (AIRS) data on Aqua, comparisons with High-resolution Infrared Radiation Sounder (HIRS) data on NOAA-15 and NOAA-16 and a limited number of forward model comparisons. The cold bias is consistent with a central-wavenumber shift on the order of -4 cm-1 (towards longer wavelengths) with respect to the original channel 6 SRFs. The original (Rev.D) channel 6 SRFs are included in the above GOES-13 download link, and they have been used for all GOES 13 Imager calibration processing before Aug. 1, 2008 (including Post Launch Testing and the NOAA Science Test).

Version 2: ITT Updated (Release Rev.E1, 2008)
In response to the cold bias detected in channel 6 imagery during post-launch testing, ITT re-evaluated the pre-launch test data and provided updated SRFs for channel 6 which shifted their effective central wavenumbers by about -1.2 cm-1 (towards longer wavelengths). The ITT-updated SRFs are included in the above GOES-13 download link and the Calibration and Alignment Handbook information for GOES-13. The ITT Rev.E SRFs were used for all GOES 13 Imager calibration processing from Aug. 1, 2008 to March 26, 2009.

Version 3: STAR Updated – Currently Operational
NOAA/STAR has evaluated the original cold bias findings, and it has also analyzed a set of observational comparisons with both AIRS and IASI data for year 2008. This has led to another update to the channel 6 SRFs which shifts the ITT updated SRFs by a further -2.1 cm-1 (towards longer wavelengths). Thus the STAR-updated SRFs have a total effective shift of about -3.3 cm-1 with respect to the original channel 6 SRFs. The STAR-updated SRFs are included in the above GOES-13 download link, and they have been used for all GOES 13 Imager calibration processing after March 26, 2009.

The updated shifted GOES-13 Imager channel-6 SRF reduces the overall cold bias. Users need to adjust their conversion from radiance to brightness temperature for this channel. For each of these SRF versions, the GOES Calibration web site contains all of the coefficients for Conversion of GVAR Infrared Data to Scene Radiance or Temperature for GOES-13 Imager channel 6.



GOES-14 Imager SRF History

Note that three versions of the spectral response functions (SRFs) for the GOES-14 Imager are presented on this website, along with the related calibration parameters associated with each SRF version. These different SRFs correspond to different releases of the Calibration and Alignment Handbook by the instrument vendor ITT.

Release Rev.D – Discontinued on Nov. 24, 2009
These are the SRFs provided by the instrument vendor in Release 2005, Rev D. They have been used for all GOES 14 Imager calibration processing before Nov. 24, 2009 (when GOES-14 was undergoing Post Launch Testing, but before the NOAA Science Tests).

Release Rev.E1 – Discontinued Aug. 9, 2011
These are the SRFs provided by the instrument vendor in Release 2008, Rev E. They have been used for all GOES 14 Imager calibration processing between Nov. 24, 2009 (including the very end of Post Launch Testing and including the NOAA Science Tests) and August 09, 2011.

Release RevH plus STAR correction – Currently Operational
These are the SRFs provided by the instrument vendor in Release Rev H, 2011, except in IR channels 3 and 6 where the original RevH SRFs have been shifted by -8.25 cm-1 and -0.25 cm-1 wavenumbers, respectively. The shifts to the channel 3 and channel 6 SRFs are the results of studies by NOAA/STAR using GSICS and other inter-calibration techniques which detect scene brightness-temperature biases between the GOES-14 post-launch NOAA Science Test data and the IASI instrument. These SRFs will be used for all GOES-14 Imager calibration processing starting after Aug. 09, 2011.

GOES-15 Imager SRF History

Release Rev E1 – Discontinued Aug. 9, 2011
These are the SRFs provided by the instrument vendor in Release 2008, Rev E. They have been used for all GOES 15 Imager calibration processing before Aug. 09, 2011 (including Post Launch Testing and the NOAA Science Tests).

Release RevH plus STAR correction – Currently Operational
These are the SRFs provided by the instrument vendor in Release Rev H, 2011, except in IR channels 3 and 6 where the original Rev H SRFs have been shifted by -6.25 cm-1 and +0.50 cm-1 wavenumbers, respectively. The shifts to the channel 3 and channel 6 SRFs are the results of studies by NOAA/STAR using GSICS and other inter-calibration techniques which detect scene brightness-temperature biases between the GOES-15 post-launch NOAA Science Test data and the IASI instrument. These SRFs will be used for all GOES-15 Imager calibration processing starting after Aug. 09, 2011.