20060406: NOAA 15-18

*Topic*:
  Updated AMSU-A antenna parameters  for NOAA-18 and information on LCC 
operations

*Date/Time(UTC) Message Issued:*
   6 April 2006 1300 UTC

*Satellite(s) Involved:*
   NOAA-15 - 18

*Instrument(s) Involved:*
   AMSU-A

*Product(s) Involved/Affected:*
   All

*Date/Time(UTC) of Initial Implementation:*
   11 April 2006, TBD  UTC

*Details/Specifics of Change:*
Beginning with the launch of NOAA-18 we implemented an algorithm to detect and correct Lunar contamination in the AMSU-A instrument data for NOAA-15 through 18. Since the implementation, we have noted that the AMSU lunar correction algorithm and implementation currently do not meet the user expectations, and will require further investigation and fine tuning. The lunar detection appears to be working fine and flags are set in the level 1b data when the moon is in the AMSU space view. User software should utilize this flag in the level 1b data and treat the lunar contaminated data at his/her own discretion. Meanwhile, ORA scientists will investigate the correction algorithm. This investigation may take some time before a working algorithm can be developed, given the complexity of the problem.

In an effort to improve the correction ability of the algorithm for NOAA-18's AMSU-A, the instrument scientist has examined the current corrections and is providing a new set of antenna parameters. We plan to implement this change on April 11 along with the normal AVHRR visible calibration update. The actual values to be used are provided below. We are providing test data on the anonymous ftp site (ftp://metroweb.nesdis.noaa.gov/pub/test/). This began with orbit NSS.GHRR.NN.D06095.S1609.E1754.B0451516.GC.

NOAA-18 AMSU-A: Antenna parameters(derived from on-orbit data)
for Lunar contamination correction
------------------------------------------------------
Ch.#  Alpha_s     Alpha_0  Delta_s    Delta_0    beta
------------------------------------------------------
 1  1.8759      -0.1976   1.4540     0.0370    0.0134
 2  1.5690      -0.1976   1.4500     0.0000    0.0129
 3  1.4600       0.2318   1.4010     0.0080    0.0120
 4  1.4340       0.2318   1.4040    -0.0020    0.0120
 5  1.4040       0.2318   1.4470    -0.0090    0.0120
 6  1.4080       0.5930   1.4310    -0.0250    0.0120
 7  1.4460       0.5930   1.4100    -0.0340    0.0120
 8  1.3860       0.2318   1.4570    -0.0330    0.0120
 9  1.3950       0.5190   1.3950     0.0000    0.0120
10  1.3950       0.5190   1.3950     0.0000    0.0120
11  1.3950       0.5190   1.3950     0.0000    0.0120
12  1.3950       0.5190   1.3950     0.0000    0.0120
13  1.3950       0.5190   1.3950     0.0000    0.0120
14  1.3950       0.5190   1.3950     0.0000    0.0120
15  1.3320       0.5190   1.4490    -0.0460    0.0120
----------------------------------------------------------

*Contact Person(s) Name/Email/Phone Number for Questions:*
 Emily Harrod,  Emily.Harrod@xxxxxxxx  301-457-5247 ext. 117, operations support
 Dr. Tsan Mo,  Tsan.Mo@xxxxxxxx 301-763-8136 ext. 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 
statuss
http://www.oso.noaa.gov/daily-news/index.asp <http://www.oso.noaa.gov/daily-news/index.htm> - SOCC morning reports

*******************************************
*
* Emily D. Harrod
* NOAA/NESDIS/OSDPD/IPD
* Computer Operations Branch
* Pre-Product Processing Group
* E/SP11, Federal Building #4, room 0318
* 5200 Auth Road
* Suitland, Maryland  20746-4304
* USA
* voice 301-457-5247 ext 117
* fax   301-457-5199
* email Emily.Harrod@xxxxxxxx
*
*******************************************


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