Topic:
Clock Offset Corrections
Date/Time(UTC) Message Issued:
1 November 2002; 1830 UTC
Satellite(s) Involved:
NOAA-15
Instrument(s) Involved:
All
Product(s) Involved/Affected:
All data users
Date/Time(UTC) of Initial Implementation:
5 November 2002 2359 UTC
Details/Specifics of Change:
The Satellite Operations Control Center (SOCC) announced a special
spacecraft clock correction for NOAA-15 to remove residual clock errors and
bring the error within the range of +/-75 milliseconds. The following SOCC
information bulletin was issued:
"NOAA-15's Elapsed Time Clock (ETC) is biased by -7.7 milliseconds per day
to compensate for a positive clock drift. It is necessary to subtract 275
milliseconds from ETC to eliminate the clock offset. This update is
scheduled for November 5th, 2002 via SCT at 23:59:00Z for the control OBP.
The standby OBP will be updated via real time command (in the schedule)."
The Information Processing Division will update its clock drift file to
reflect the correction in the level 1B processing. The user should not be
affected by this change. A notice will be issued identifying the first
orbits affected after the change when the information becomes available.
Contact Person(s) Name/Email/Phone Number for Questions:
Emily D. Harrod/Emily.Harrod@noaa.gov/301-457-5247 ext 117
Web site(s) that contain other relevant information (where applicable):
http://www.oso.noaa.gov/daily-news/index.htm - SOCC morning reports
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