Running the Fringe Checker
Once all the RtFC processes are running and the disks are recording,
you are ready to fringe test. It is recommended you first check
sampler statistics of the data looking at the cdisko monitoring. If you
using a config file for ui.pl, you should make sure the values are
sensible before you start ui.pl. All fringe testing is run from ui.pl.
As this is an interactive program there are many ways to run this. The
following is a guide.
Check which observatories are connected:
Disable Parkes because it is not tracking yet, and Ceduna as we will do
it later once we know we have fringes to other telescopes
Check the integration time we are using then set to a sensible value:
> disable Pa
> int 0.1
Set the number of frequency points to create (note incorrect term)
Start a fringe check running for the specified UT time
> nchan 512
The data will be copied to Parkes, the data passed to the software
correlator and the result plotted using pgplot and put on the web
at http://www.evlbi.atnf.csiro.au/RtFC (pkpam, if at Parkes).
There is a bit of a delay offset to Mopra. Correct for this and
recorrelate the data to ATCA only
This will use the data already on disk and recalculate the
using a different clock offset.
Once you have the good clock offsets, its is worth adding them to your
offset Mp 3.4
> disable Pa Ho Cd
> recorr 03:34:34
Get some Ceduna data now. To save time, change the integration time
to 250 msec. Grab a time 1 second before or after a sucessfull
Remember to set the integration time etc back
> enable Cd
> int 0.25
> grab 03:34:35
If you get impatient due to a slow download, you can "recorr" before
the data has arrived. The correlator will correlate up to the length of
the end of the smallest data file.
> disable Cd
a station has a suspected 1 second (or more) offset the "offset"
command is not suitable. Use secoffset. You have to "regrab" the
data after changing secoffset
secoffset Mp 1
> grab 03:35:99