TT9 - The Telemetry Tracker 9000
Mendygral, P.J. - primary developer
Morgan, D. - primary developer
Anderson, C.S. - primary developer
Nichols, J.S. - concept and management
Description
TT9 is a massively parallel quality analysis and quicklook processing system front end to the Chandra X-ray Observatories standard
processing, AP, system located at the
Operations and Control Center, or OCC, in Cambridge, MA.
The system is written in Perl and CShell scripts and uses the pipeline processes developed by the CXC software team. Originally
developed to run quicklook, or first glance, processing on incoming telemetry, the system has evolved into a full quality
analysis system and is part of fully automated AP feeding system. Data management is managed through a MySQL backend and is
interfaced by both a CLI and GUI client.
Details
Chandra orbits the Earth, but at very far distances. At apogee Chandra is more than one third of the way to the moon. Therefore,
communication with the observatory is limited to a few hours a day via the Deep Space Network. Data is first recorded on the
satellite on the SSR, or solid state recorder. The recorded data is then transmitted through the DSS when in communication, or COMM,
with Chandra and delivered to JPL in Pasadena. JPL adds some headers to the data packets and then transmits it to the OCC. The
data is loaded into a system called the NRT, which is like a big database of data packets. That data is then packed and ftp'd to
my group, Data Systems Operations.
TT9 is the next system to handle data in the chain of events. TT9 monitors for new telemetry files, or dumps, and starts processing
when a new file is encountered. Telemetry dumps contain data for piece(s) of observations that must be checked for quality. Due
to the long distances and many systems telemetry passes through to get to us there is plenty of opportunity for data corruption.
TT9 processes these dumps to produce a first glance quicklook at an observation always looking for any corruption. If corruption
or other strange glitches are encountered a new dump file is often needed. After passing many levels of checks, a dump file is
flagged as ready for the AP system.
To be continued...
Papers and Presentations
