The AVHRR synchronization problem continues. In order to be able to perform
troubleshooting and engineering observations without disrupting AMSU and
other products, SOCC is proposing that we switch to using the stored AIP
data (SAIP). This will give them the leeway to use the AVHRR sync delta, so
that the AVHRR can be monitored.

We expect that users will not have a problem with the SAIP data. However, a
test has been scheduled for Thursday, August 3, 2000, beginning around
00:00z. We will produce SAIP data in parallel to the operational data and
provide it in "P1B and P1S" data sets as we did with previous parallel
tests. The users will see a difference in the dataset name but not in the
data format. The new names will look exactly like the operational names
except the instrument qualifier section of the name will end in an "S"
rather than an "X"; for example AMBX is data from AIP and AMBS is data from

Also, whenever and SAIP orbit is not available, an AIP orbit will be
substituted. You will be able to identify this by the dataset name.
Please let us know immediately if you have any problems with the test or
with switching to using SAIP operationally.

Please provide your user input either to myself or Emily Harrod. The test
period will be 24 hours. After the evaluation of the test has been made a
decision will be made as to whether to switch to SAIP vs GAC.This decision
will be made the week of August 7th. If it is decided to switch to SAIP then
the scheduling of SAIP will occur the week of August 14th. Your response to
the test will be appreciate the following day if at all possible.

The following are the short term and long term objectives that we hope to
accomplish from Thursday's test.

> Short term: To allow for AVHRR troubleshooting and engineering
> observation without disrupting AMSU and other products, we would like to
> get to a SAIP record/playback schedule as soon as can be reasonably
> coordinated with scheduling.
> Long term: If, as suspected, it is shown that the AVHRR is not reliable
> for operations, we would like to reconfigure for GAC playbacks after a
> suitable test period. Although the GAC reconfiguration seems
> counter-intuitive at first, the reduced GAC playback times will allow us
> to maximize data retrieval in the long term.

Please feel free to contact us if you have any questions or concerns.

Emily D. Harrod
E/SP13 Room 0308 FB#4
5200 Auth Road
Suitland, Md. 20746-4304
(301)-457-5247 phone
(301)-457-5199 fax

Cecil A. Paris
Calibration Physical Scientist
Phone 301-457-5247
Fax 301-457-5199