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MetOp-2/A, MHS, Correction of Cold Target Calibration, 19 June 2007 - Issued: 20 June 2007; 1245 UTC

Date/Time(UTC) Message Issued:
19 June 2007, 1245 UTC

Satellite(s) Involved:
MetOp-2/A

Instrument(s) Involved:
MHS

Product(s) Involved/Affected:
Product brightness temperatures

Date/Time(UTC) of Initial Implementation:
19 June 2007, Time 1309 UTC

Details/Specifics of Change:
MetOp-2/A cold target calibration correction parameters were updated on June 19 approximately 1309 UTC beginning with the following orbit.
NCS.FRAC.M2.D07170.S0936.E1116.B0344849.SV on the operational system
NCS.FRAC.M2.D07170.S0755.E0932.B0344748.SV on the parallel test system

The instrument scientist, Nigel Atkinson, discovered an error in these parameters when comparing NOAA level 1b brightness temperatures to those of Eumetsat. Tsan Mo, NOAA instrument scientist, concurred with his findings. In researching the problem, NOAA discovered that the MHS Cold Space Temperature Correction data was not implemented correctly in the calibration database when the last update was performed on February 27, 2007 at approximately 1450 UTC. The first orbit processed after that change was:
NCS.FRAC.M2.D07058.S1314.E1325.B0185959.SV

Dr. Atkinson noted that "brightness temperatures did not agree at all well with the global. Discrepancies for the first 350 lines of this file, NSS.MHSX.M2.D07169.S0815.E0958.B0343334.SV, are on average for the 5 channels: 1.15K, 0.36K, 0.55K, 0.64K, 0.41K, the NOAA-processed data being warmer."

The correct parameters now being used are:
# Warm load correction factor for each reference instrument temp #
0, 0, 0, 0, 0
0, 0, 0, 0, 0
0, 0, 0, 0, 0
# Cold space correction factors for each space view and channel
1.48, 0.43, 0.71, 0.71, 0.46 ! Space View 0
1.82, 0.50, 0.78, 0.78, 0.51 ! Space View 1
1.23, 0.39, 0.63, 0.63, 0.42 ! Space View 2

Please accept our apology for any problems this error may have created.

Contact Person(s) Name/Email/Phone Number for Questions:
Emily Harrod Emily.Harrod@noaa.gov 301-817-3882 operations support
Tsan Mo Tsan.Mo@noaa.gov 301-763-8136 x 137 Instrument Scientist

Web site(s) that contain other relevant information (where applicable):
http://www.osdpd.noaa.gov/PSB/PPP/PPP.html - History of level 1B notices
http://www.ssd.noaa.gov/PS/SATS/messages.html - All user notices
http://www.oso.noaa.gov/poes/index.htm - SOCC polar satellite status
http://www.oso.noaa.gov/goes/index.htm - SOCC geostationary satellite status
http://www.oso.noaa.gov/daily-news/index.asp - SOCC morning reports


--
*******************************************
*
* Emily D. Harrod
* NOAA/NESDIS/OSDPD/IPD
* Computer Operations Branch
* Pre-Product Processing Group
* E/SP11, NSOF, room 1460
* 4231 Suitland Road
* Suitland, Maryland 20746-4304
* USA
* voice 301-817-3882
* fax 301-817-3902
* email Emily.Harrod@noaa.gov
*
*******************************************


ppp@nesdis.noaa.gov

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