[evlatests] OTF Modes -- Cancel Red Alert ...

[Rick Perley]

     My previous report on a curious failure in the OTF modes should be 
trashed.  Steve has provided the correct answer:

     It's the DELAY, stupid!

     The OTF modes move both the delay and fringe tracking centers along 
the selected path.  The target source is therefore offset from the delay 
center -- which introduces a significant delay for all observations.

     I then ran the delay program 'FRING' for all data, and applied 
these.  The subsequent CALIB solutions show beautiful beam cuts (except 
for the most western antennas, where interpolation effects are showing up).

     I'm now ready to do the 'real' tests, which will:

     1) Traverse only the main beam (maximum throw of 0.25 degrees from 
center).
     2) Make the phase step size larger, so as to enable more accurate 
delay calculation.
     3) Make cuts in various angles (declination, RA, slanted)
     4) Do the cuts at various elevations and azimuths.
     5) Employ referenced pointing to stabilize the beam.  (The effects 
of pointing errors are obvious in the trial cuts made in this test).

     These tests are pretty short -- 30 minutes to an hour should 
suffice.  The schedulers should let me know when we can do these. Soon 
(today?) is fine with me.

     Rick