Multi-source files

It is assumed that the correct velocity information is in the SU table. If it is missing, then enter it with SETJY as described in § 5.

• Select the sources that you wish to shift (there is not much point to shifting calibrators) with the sources adverb. The unselected sources are copied unshifted to the output file.
• You may select by time range as well with timerang.
• Select the desired frequency with the usual adverbs selband, selfreq, and freqid.
• It is unlikely that you will have more than one subarray in the data at present, unless somehow you have already run DBCON (which you shouldn't have; run CVEL first and then DBCON). Select all subarrays for shifting by leaving subarray at zero.
• flagver If -1 no flagging is applied, otherwise specifies the FG table to apply, and flagver=0 means the highest FG version available. There is no FG table associated with the output file.
• It is very important that the bandpass correction is applied before you shift the spectra. The bandpass correction applies to the data in their original fixed frequency frame. doband can take the value 1 (average all entries in the BP table for each antenna) or 2 (use nearest entry). I suggest doband=1. Use bpver to specify the version of the BP table to apply. You cannot apply the bandpass correction with any validity after running CVEL.
• In principle, there can be source-specific Doppler offsets hiding in a CL table. This might be the case with VLA or VLBI data, but it is not the case with ATCA data. Set gainuse=-1.
• Leave aparm(1) through to aparm(6) at zero for multi-source files.
• Set aparm(7)=0 for ATCA data (the ATCA and VLBI arrays have a similar geocentric coordinate system) and leave aparm(8)=0 so that you are warned of unduly large shifts.

inname,inclass Input visibility file inseq,indisk

outname,outclass Shifted visibility file outseq,outdisk

sources 'NGC9899',' ' Specify sources to shift

timerang=0 Select all times

freqid=1 Select frequency ID

subarray=0 Shift all subarrays

fgver=0 Highest FG table

doband=1 Apply band pass correction

bpver=1 Select BP table version

gainuse=-1 Nothing hiding in CL table

aparm=0 Defaults correct