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Guidelines for data processing
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The ALFA Ultra Deep Survey
team has adopted the livedata/gridzilla package for data
processing. This package was originally developed at the ATNF for
HIPASS data reduction but has since been generalised for use for
other single-dish spectral-line observations where large data volumes
are involved. The software is distributed as part of the ATNF package of
aips++, and
can also interface with Multibeamview which is part of the
karma
software package.
Data reduction is split into two or three stages:
- LiveData: this reads the sdfits/bdfits format and applies system
temperature calibration, bandpass calibration, heliocentric correction,
spectral smoothing, and writes the data out in sdfits format.
- Gridzilla: this reads the calibrated sdfits data produced by livedata
and creates a data cube using user-specified gridding parameters. The
data cube has axes of RA, Dec and velocity or frequency.
- Cubecat: sometimes (if large data quantities are involved) gridzilla
produces several cubelets which cubecat can concatenate.
It is recommended that cubes be viewed with
kvis (part of
karma),
although the viewer in aips++ is also excellent.
Please note that the ALFA beam labelling convention is 0 to 6, whilst
livedata and gridzilla will refer to beams 1 to 7.
Bugs/enhancement requests to
Mark Calabretta.
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