[mmaimcal] Astronomical use of the WVR spectrometer?

[Al Wootten]

Today at the DH meeting we discussed whether a spectrometer was necessary
for the San Pedro site, as antennas are assembled (four at a time) and
undergo initial testing.  This was at the end of the meeting, and my thought
train was impaired by a hunger for oxygen, so I didn't point out that each
antenna will have a WVR spectrometer.  The WVR seems to be maintaining the
role of stealth instrument.  The only use for such a thing that I
can think of is to do line pointing.  I can't recall the specifics of Martina's
backend now but I think I recall that the central channel is sufficiently
narrow that it might be of some use in detecting galactic water masers for
pointing tests, if the site would support that.  It might be useful for SiO
masers, too.  Either way, we might be considering a degree of flexibility which
has not been considered before.  Some DHs didn't like the idea of yet another
GBT spectrometer clone heading for the San Pedro site.  Perhaps Min and
Bryan could discuss this for our next meeting, whenever that will be.  I'll be
on a Japan-bound airline next Monday; perhaps you all could discuss this on
the phone without me.  Astronomy with a folded spectrum is perhaps a new
concept but it might work.  Sensitivity at a low altitude site like San Pedro
using a cooled Schottky may also offer a challenge.  But all we need I think
is a few bright sources out of the ecliptic, and for line pointing here we
essentially turn our multi channel wreck of a backend into a three channel
device, though we have a dandy receiver and transparent sky.

Clear skies,
Al