2. Start CATAG

The CATAG program measures the pointing offsets, calculates a new set of pointing parameters and loads these into the ACCs. CATAG must be running on XBONES for Reference Pointing mode to be used. If it is not running, type catag in an XBONES window to start it.


The observers select the pointing pattern, length of time on each pointing, and IFs to use to calculate the pointing correction with CAOBS. Each point pattern is made up of six sub-scans with the antenna at six different offsets:

sub-scan	1	0	0
sub-scan	2	+az	0
sub-scan	3	-az	0
sub-scan	4	0	+el
sub-scan	5	0	-el
sub-scan	6	0	0

At the conclusion of the pattern, CATAG will automatically determine the offsets, take a median, write a new $ATCA_PPARAMS:pparams.dat file. With pointing=UPDATE mode it will download the measured offsets to the global solution and loads them into the ACC.

Note: CATAG does not detect when you no longer need a local solution. At this stage it is up to the (expert) user to determine this.

If required, please see the additional CATAG information.