Minutes from Pasadena Open Meeting of the Future of VLBI

There were presentations by Greg and Shri and then a general
discussion.  Greg's written summary of comments follows:

Open meeting input:

Attending (15-20):  

Eric Agol, Sterl Phinney, Judy Cohen, Tony Readhead, Tim Pearson,
Shri Kulkarni, Edo Berger (Caltech)
Luis Ho, Jeremy Darling (Carnegie)
Glenn Piner (Whitier College)
Dayton Jones, Pam Wolken, Bob Preston (JPL)
Charles Lillie (Northrop Grumman)
Others unrecognized and part-time.
Greg Taylor (NRAO)

It was suggested that we have an open draft for review and comment by
the community at large.  A compromise suggested was to post interim
documents (e.g. a summary of future technical capabilities, or the
results of a statistical study of VLBI publications).  This would also
be less confusing as these would clearly be seperate from the final
report.

It was pointed out that the current low level of involvement of
university groups is the result of funding decisions made by NSF.
Also there is a fairly clear bias at the major universities against
hiring radio astronomers.

Rather than pursuing big facitlities (as NRAO does), the university
groups might want to focus on mission dedicated experiments.  We
should think about collaborations between the observatories and the
universities such as is happening with some GBT instrumentation.

It was mentioned that a JPL array with 10 x 70m equivalent collecting
area is under study.  This array might go up to 40 GHz, and could have
some time available for VLBI.

Someone pointed out that the VLBA was completed but never upgraded,
besides the addition of the 86 GHz capability, which wouldn't have
happened if MPIfR hadn't provided funding for roughly half of it up
front.  Greg pointed out that there is a perpetual shortage of
Research Equipment (RE) funds at NRAO.

It was suggested that we look into NASA/NSF collaborations to fund
projects.  Especially in space VLBI.  It was mentioned that there is
some interesting work on analog optical correlators that might help
with really large data rates.

Some people felt that strategic vision was lacking at NSF.  While
there are advantages to "curiosity driven" science, it also means that
NSF won't spend any money unless people come along and tell them 
what they should fund.  

Student support for VLA and VLBA projects was strongly encouraged by
several people.  A program analagous to that for the GBT should be
established by the NRAO director for the VLA and VLBA.  NSF increase
NRAO's budget to support this activity at the level of $0.5
million/year.  This should be given the highest priority.  Somewhere
in the middle was support for publications and observing trips and at
the bottom was summer salaries for faculty.

The software situation was perceived as generally repulsive to new
users of the VLBA.  While AIPS is adequate for data reduction it is
percieved to be difficult to learn.  It was stressed in particular by
outsiders (and talking to other optical/IR types) that VLBA
calibration is very difficult.  People are unaware of the calibration
service offered by the VLBA, or the pipeline.  People also complained
about NRAO's archive policy, especially the need to get permission
even for data beyond 18 months that should be in the public domain.
Greg pointed out that this situation is changing.  NRAO also needs to
do a better job advertising new capabilities to the astronomical
community at large.  The NRAO newsletters and web pages are not
sufficient by themselves.

NRAO also needs to do a better job advertising scientific results.
It was asked if NGC4258 was a VLBA result and then if there were
other systems worth studying.  Someone said that if you ask a non-radio
astronomer what the VLBA has contributed the answer is the NGC4258 
and after that they are stumped.  

It was suggested that we do a study of where our summer students have
gone, especially those that have worked on VLBI.  Al Wootten might
have some general statistics there. It would be worth surveying past
summer students to get their impressions of where they would like to
go with their careers.  Other people felt that students were smart
enough in graduate school to follow the money out of radio astronomy.

It was suggested we should look beyond 10 years and consider 
what was needed to increase collecting area.  Promote more of a 
long-term vision.  Greg responded that this was beyond the scope of
the current study, but we might suggest that some follow-up
effort be directed to develop a long-term vision.  

Astrometry was generally recognized to be extremely exciting.  
The possiblility of direct distance measurements in our galaxy
and beyond is fundamentally important.

Eric Agol presented an overview of theoretical calculations showing
what a massive black hole should look like in the radio.  To overcome
scattering limitations we will have to go to 1mm wavelength to image
SgrA* but with earth diameter baselines that could be interesting.
Due to magnification by the black hole the predicted size is 10 R_s or
about 30 microarcsec for SgrA*.  This should be doable, but not on the
VLBA.

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