[evla-sw-discuss] VLA antennas and the EVLA parameters database

[Ken Sowinski]

On Wed, 28 Jun 2006, Ken Sowinski wrote:

>                      Old Wine into New Bottles
> 		          June 28, 2006
>
> I have started constructing a program to pour all the system parameters
> from the Modcomps into the EVLA parameters database.  I want to set down
> the method and rationale to give anyone who cares a chance to suggest
> better approaches or techniques.

I have now incorporated delay parameters into this process.
Rather than send the entire document again and force everyone
to read it all I include here only to addtions for delays.

For each pad:
WGDELAY      This is calculated from the baseline coordinates
              and is a best estimate of the physical path length
              from the antenna to the center of the array.  The
              WG run from the center of the array is not included.
FIBERDELAY   This is just the empirically determined  number from
              recorded in SYSPATHF which correctly places an EVLA
              antenna in the VLA delay space.

For each antenna:
WGCHAN       The modem channel as recorded in the ANTENNAS file.
              It can be used the estimate the effective path length
              through the waveguide.
For each band:
DELAYA       These are the peculiar delays from the appropriate
DELAYB       IF file for each antenna, band and IF.
DELAYC
DELAYD


I note here that the executor looks for an antenna based parameter
called DELAY which can be used to specify an antenna based adjustment
to the total delay.  I note also that we have no easy way to adjust
the delays for all bands at a single IF when the DTS system resyncs
itself and changes the throughput delay of the DTS system.