IMPORTANT: In order for CABB to fold pulsar data correctly, a predictor file is needed:
On caccc1, type:
caccc1> psrpred
Choose the pulsar name, e.g.:
psrpred> J1302-6350 or
psrpred> J0835-4510 for Vela
follow the defaults thereafter
To change modes it is necessary to:
stop the current scan
cccversion: pulsar mode works in any version.
in cacor, open the edit menu
select the edit button in the cacor gui,
select the appropriate config
edit> get psr32_2f_favg4
The psr32_2f_favg4 config has 4 “frequencies”. F1 and F3 are continuum bands with 2048 1MHz wide channels. F2 and F4 are the pulsar data - the continuum data is averaged into 4MHz wide channels, then each channel binned into time bins as defined by the predictor file.
and program the correlator
edit> prog
Check that all blocks program correctly. If any blocks report an error, they need to be programmed again, e.g.:
edit> prog 8 or edit> prog 8 27
if you are having problems with a block you can try
edit> prog N cal which just reprograms the calibration (sometimes works)
<CR> to return out of the edit menu
Calband will be set to the default values - which is what is required
start observing a calibrator, e.g.
caobs> track 1
Check for rear transition module (rtm) problems
F1 and F2 Datalinks (separate tabs in the CACOR gui) should not have red error messages, and the 1ms values are in the range 2000 - 13000 (i.e. not 260 000). Fix with:
cacor> rtminit
Check (from non-binned autocorrelations (F1, F3) in spd) for “big humps”. To fix, reprogram the relevant block.
To determine the block, note antenna, frequency (1 or 2), and polarization (A or B) - then read off the block from the relevant Datalink tab on the CABB GUI.
Check (in spd) individual baseline amplitudes and phases for discontinuities and fix by reprogramming relevant blocks
Check for memory problems - every second cycle is obviously bad. Fix with:
cacor> reset mem
Setup standard flagging
cacor> fflag f1 birdies
cacor> fflag f2 birdies
NOTE: all flagging is cleared every time you exit from the edit menu
Check that tvch is set to appropriate values
Check that delavg is set to an appropriate value
Standard setup follows (i.e. check sampler levels, and for fringes, then dcal, acal, pcal etc.)
Note: As of end October, 2013, there is a bug in the cacor software that means that the Tsys is not being calculated correctly for the second (F3) frequency.