Swift Pipeline Changes for new GRB Data

[terri@milkyway.gsfc.nasa.gov]

Swift Data Center (SDC) Implements Changes to Process Burst Data More
Quickly

July 12, 2005


The SDC has recently put in place several processing enhancements
that result in faster processing and availability of the first Swift
data from GRBs.
This note describes the changes you can expect to see in data on the SDC
Quicklook site: http://swift.gsfc.nasa.gov/cgi-bin/sdc/ql?

The pipeline now uses 99x segment numbers to quickly process XRT and
UVOT
data in parallel. Beginning July 11, 2005, the first data to arrive on
the
ground from an autonomous slew snapshot is being split into separate
segment numbers as follows:

TDRSS messages (990: to be completed)
XRT science (991)
UVOT science (992)

Segment number 000 will continue to be processed as previously, and
will contain all hk and auxiliary data, as well as BAT, XRT and UVOT
science data. At the same time, during the first 24 hours, as soon as
new
XRT science data is received, then segment 991 will rerun, with only
XRT processing, and will complete in significantly less time that the
entire
pipeline (segment 000). Similarly, during the first 24 hours, when new
UVOT
data is received, segment 992 will rerun with only UVOT processing. BAT
data will continue to come out quickly in segment 000; these
modifications
will not change that.

The 99x segments are temporary, and are meant only to be used in the
very early analysis. They will not go to the permanent archives as they
contain no unique data that is not in segment 000.

TDRSS messages will eventually go into segment 990. Currently they
are not being handled properly but this is in the process of being
corrected.

EXAMPLE:

Here is how the three sequence numbers work for a new GRB. For target ID
145581, the first data would be available on the Quicklook site in the
following sequences:

00145581000 Full autonomous sequence (BAT, XRT and UVOT)

00145581991 just XRT data from autonomous sequence

00145581992 just UVOT data from autonomous sequence

00145581001 First observation after autonomous sequence (BAT, XRT and
UVOT)

Each sequence also contains all the necessary auxiliary data
and log files for complete analysis of the data contained within.


While this substantial change has already resulted in data being
available
more quickly to the community, we expect that it will take some time to
find
and fix any remaining bugs in the system. Please bear with us while we
track these down. If you encounter problems please report them to us via
the feedback form at: http://swift.gsfc.nasa.gov/cgi-bin/Feedback

Best Regards,
Padi Boyd
Swift Science Center

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