[evlatests] Holography tool

[Walter Brisken]

Hi testers,

Holography style rasters are a useful way to learn about optics and 
pointing of VLA antennas.  While simple in principle, writing holography 
files is tedious and error prone.  I have written a tool to help in the 
generation of holography observe files.

To use, first create a valid observe file with a single scan on the 
calibrator source that you will be observing.  Make sure your file is in 
stop times and that the stop time is correct.  Then feed this file to my 
program HoloMaster as follows:

HoloMaster HoloCal.obs 13 az 15 3.0 > Holo.obs

This will generate a new observe file called Holo.obs from the single 
calibrator scan in HoloCal.obs.  The pattern will be a square raster with 
13 pointings per side, scanning in azimuth with a minimum interval between 
calibration of 15 minutes.  There will be 3.0 pointings per beamwidth.

Note this script will not fare well for very large rasters (ie ones with 
large slew times from the source to the edge of the raster).  Normal 
rasters for L-band and higher freq should be fine.  Also note that you 
will still need to instruct the operators in the "Special Instructions" 
to specify reference antennas.  There are special additional requirements 
for use of EVLA antennas as reference ants -- contact me.

HoloMaster can be found in /home/mchost/evla/bin .  Please report any bugs 
you might find to me.


-W