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Description of GBT FITS files

At the time of writing, the following Managers either create or are planned to create FITS files. The simpler FITS files are described here, othere are referenced by GBT Software Project Note identifier.

Antenna
This Device FITS file is described in GBT Project Software Note 7.0, ``GBT Antenna FITS File Specification.''
Archivist
Each device FITS files as generated by the Archivist contain time-tagged rows of values from a single M&C data monitor sampler for the duration of a scan. The selection of samplers to be included with the scan data set is fully under the control of the user via the Archivist. It is used to attach ancillary information to a scan, usually for engineering purposes. The primary HDU follows the standard with the addition of the keywords DEVICE, MANAGER, SAMPLER, DELTA, and UTSTART as described for the Log Fits files above. Since the contents of the BINTABLE are generated dynamically depending on the M&C sampler selected, the value of the keyword EXTNAME is arbitrarily given as the name of the sampler.
Berkeley Caltech Pulsar Machine (BCPM)
This Device FITS file is described in GBT Project Software Note 16.0, ``Berkeley Caltech Pulsar Machine FITS File Specification.''
Calibration
This Device FITS file is described in GBT Project Software Note 11.0, ``GBT Calibration FITS File Specification.'' The Primary HDU follows the standard described above except the definitions of DATE-OBS, OBJECT, OBSID, and SCAN are bent a little. The file contains one or more RX_CAL_INFO tables.
DCR
This Device FITS file is described in GBT Project Software Note 13.0, ``GBT DCR FITS File Specification.''
GO (user interface)
This Device FITS file is described in GBT Project Software Note 8.0, ``GBT GO FITS File Specification.''
Holography
This Device FITS file is described in GBT Project Software Note 9.0, ``GBT Hologrphay FITS File Specification.''
IFManager
This Device FITS file is described in GBT Project Software Note 10.0, ``GBT IFManager FITS File Specification.'' The Primary HDU follows the standard described above. The IF table is the only table in the file.
LO1
This Device FITS file is described in GBT Project Software Note 6.0, ``GBT Tracking Local Oscillator FITS File Specification.''
Optical Pointing Camera
This Device FITS file is described in GBT Project Software Note 14.0, ``GBT Optical Pointing Camera FITS File Specification.''
ScanCoordinator
The ScanCoordinator produces a FITS file called the scan log. There is one scan log for each project. The scan log was mentioned above as an exception to the standard primary HDU for device FITS files It is an exception because rather than describing a single scan, it describes sets of scans; indeed it is the means that one can readily determine the set of FITS files that represent a specific scan. The scan log's BINTABLE (EXTNAME is ScanLog) contains three columns: the scan nominal scheduled start time as a string (DATE-OBS), the scan number as an integer (SCAN), and a scan description as a string (FILEPATH). Each scan will produce a set of N rows with the same DMJD and SCAN. The FILEPATHs for the first (N - 2) rows are the paths (starting at the project directory) for all the FITS files for the scan. The next row's FILEPATH column contains a string indicating the scan has begun, e.g. ``SCAN STARTING AT 51899 18:33:01.'' The purpose of this row is to indicate to any program reading the file asynchronously that the list of (N - 2) FITS files is complete. The final row for a scan contains a string indicating that the scan has ended, e.g., ``SCAN FINISHED AT 51899 18:36:04.'' The purpose of this row is to indicate that all the contents of the FITS files have been flushed to disk and the files have been closed for writing.
SpectralProcessor
This Device FITS file is described in GBT Project Software Note 12.0, ``GBT Spectral Processor FITS File Specification.''
Spectrometer
This Device FITS file is described in GBT Project Software Note 5.0, ``GBT Spectrometer FITS File Specification.'' The Primary HDU follows the standard described above with the addition of the keyword BANK. The file also contains the standard STATE binary table extension to describe the generated switching signals, however, the Spectrometer is able to measure the integration time for each switching signal phase regardless of their source. These values are entered into the ACT_STATE binary table extension.

All of these produce a Primary Header with no Data Array, followed by (generally a single version of) one or more binary tables extension.


next up previous
Next: FITS documentation, standards and Up: gbtFits Previous: A proposed route to
Bob Garwood
2011-07-23