Reducing Mopra Data
For data collected with MOPS
To reduce on-the-fly mapping data Livedata and Gridzilla packages are used. Livedata
is an ATNF package which processes the raw rpf files into sdfits files with correct
position stamps on each spectrum. The sdfits file is then further processed by a
package called Gridzilla, which regrids the sdfits files and creates a FITS data
For position switching observation, a package called ASAP is used.
Please follow this
link for further information.
For data collected with MPCORR (prior to Aug 2005)
Mopra Frequency Correction
Dual polarisation spectral line data taken prior to 2004 may be
affected by a software bug which caused the incorrect frequency
to be written to the rpfits file. For a full explanation of the
problem see the memo below by Ned Ladd.
A perl script written by Chris Philips and Cormac Purcell is available
to correct the raw rpfits files.
All initial data reduction on MPCORR data is performed using
the program SPC
(formerly S). The Mopra correlator software writes to the proprietry rpfits
file type. SPC is capable of reading rpfits and sdfits files and
writing sdfits and fits files. Typical operations perfomed are:
bandpass (reference) subtraction for each scan, baseline fitting, post observation
doppler correction and averaging.
Package for reducing Mopra and Parkes data.
binary linux | source*
* spc source requires rpfits,
More information is available on the ATNF SPC
A tcl/tk graphical interface called Data From Mopra (DFM) has
been written for spc. DFM enables rapid reduction of position switched spectra
in two polarisations and writes out to sdfits and fits files. It is particulary
useful at the telescope in order to reduce data rapidly on the fly.
Some linux distribution will have the expectk libraries pre installed. The
rpm packages here were compiled for Redhat linux 9.0. Rpms for other linux distributions
are available on http://rpmfind.net/
After subtracting the reference positions and averaging using
spc or dfm the data can be imported to the spectral reduction
program of your choice. We recomend:
Gildas spectral line reduction software
Nice graphical reduction software by Per Bergman from the Onsala Space
Both programs read in data from files in the fits format.
A change is required in the header of the fits files output by
spc / dfm in order for them to be read into XS correctly:
The keyword CRDELTn must be changed to CDELTn in all fields.