All NOAA Polar, All instruments, End of Year and Leap Second, 1 January 2009 - Issued: 30 December 2008; 1720 UTC

Leap Second and End of Year Processing

Date/Time(UTC) Message Issued:
30 December 2008, 1720 UTC, 12:16 PM, EST

Satellite(s) Involved:
NOAA-15, 16, 17, 18

Instrument(s) Involved:

Products) Involved/Affected:
All Products/geolocations

Date/Time(UTC) of Initial Implementation
31 December 2008, Time approximately 2359 UTC, 6:59 PM, EST

Details/Specifics of Change:
The pass that crosses the year boundary will be affected for data from the NOAA-15, 16, 17, and 18 satellites.
Recorders will be stopped just before the end of the year and new recordings started at the beginning of the year.
Simply stated, the last pass of the year will be split into two parts with the data from 2008 in the first part and the 2009
data in the second part. Also, the addition of a leap second is planned for the end of the year and the 2009
data will reflect the leap second update in the timecodes. Further, all clock drift files have been updated. For NOAA-15,
16, 17, and 18 satellites these updates are made on the ground in the pre-product processor. However, for
MetOp-2/A data processing, NOAA uses the spacecraft internal timecodes, which will not be updated to include
the leap second until approximately 13 hours 49 minutes after the end of year. During this 13+ hour period, a correction
will be applied to the MetOp- 2/A data on the ground as part of pre-product processing. However, users should be advised
that it is possible that some data will be mislocated as a result of this event.

Contact Person(s) Name/Email/Phone Number for Questions:
Operations Crew Leader: 301-817-3880
Emily Harrod: 301-817-3882

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