NOAA-85, HIRS, Longwave Channels Stable, 16 December 2005 - Issued: 16 December 2005; 1530 UTC

HIRS longwave noise relatively small

*Date/Time(UTC) Message Issued:*
16 December 2005, 1530 UTC

*Satellite(s) Involved:*

*Instrument(s) Involved:*

*Product(s) Involved/Affected:*
Products using longwave channel data

*Date/Time(UTC) of Initial Implementation:*
16 December 2005, Time 1530 UTC

*Details/Specifics of Change:*
The HIRS instrument scientist reports the following:
NOAA18/HIRS has been stable for more than a month since the noise drop in late October. Currently all shortwave channels are performing well, and about half of the longwave channels meet the noise specification (with the other half near the specification). It is estimated that the impact of the longwave noise on products should be relatively small. Users are encouraged to use the data and report any problems to us. According to the NOAA18/HIRS noise investigation team, problem is likely caused by a loose lens, . In order to keep the noise at low levels, NOAA will attempt to avoid any activity that might induce vibration of the spacecraft or the instrument.

*Contact Person(s) Name/Email/Phone Number for Questions:* 301-763-8136 ext. 196 instrument scientist 301-817-4117 with spacecraft operations 301-457-5247 x 124 1B data processing

*Web site(s) that contain other relevant information (where applicable):* - History of level 1B notices - All user notices - SOCC polar satellite status - SOCC geostationary satellite status - SOCC morning reports

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