Telecon Friday 25 April 2003.

Sanders, Glenn, Fan, Blitz, Yun, Turner, Wilson, Myers, Carilli, Johnstone
Wootten  Crutcher attempted to dial in but could not connect.

Me: Crutcher chair.  Table discussion of meeting until he can assumer
leadership.  

New Ops Plan

Wilson:  ASAC report in construction, to be public at the end of May.

Brief flavor of topics in ASAC report:

Longest baseline configuration.  Tradeoff between max resolution and having
sensible intermediate configurations.  Work suggests that this is quite
possible and the current plan achieves this.  

Correlator upgrade:  enhancement endorsed.  This enhancement will
provide higher resolution in the highest bandwidth configuration.
Possible worries include aliasing at the edges of the subbands; simulation
called for.  Option for not using subbands endorsed.  Improving
channel number increases data rate.  Possible late upgrade to the first
quarter of the correlator.

Inhomogeneous array impact on science:  Project may be driven to
accept two different antenna designs which meet specifications.
Board wants a homogeneous array.  ASAC endorses single design.

Calibration plan and
Front end specifications for the receiver.  Much discussion occurs
here.  For the first, current status considered.  Highest priority is
amplitude calibration, for which the ASAC would like a 1% accuracy
for below 300 GHz and 3% above.  Two schemes being pursued for this
seem to have problems, hence a third scheme has been developed, whith
the ASAC recommends pursuing.  Science IPT needs additional resources.
ATF could be used to check out parts of the strategy, in particular
phase calibration.
On the Front End, Gain stability is a problem, particular for the
continuum with all spatial frequencies, or differential polarization.
Several memos suggest one part in 10,000 stability in one second
is required but this is demanding.  For interferometry, an order of
magnitude less is the spec.  This portion of report will be discussed
by Board on Tuesday, as it would be good to release it to the Front End
IPT.

Software:  ALMA software (aips++?) needs to be competitive in speed with
other packages.  Other packages also tested, in particular miriad.
The ASAC described some attributes which should be available.

The availability of the file containing the Operations Plan for ALMA,
Chapter 6 of the Project Plan, was announced.  It is available by a link
from the Web Agenda for this meeting.  This plan was informed by ASAC
discussion; the ASAC report of September 2001 in particular.  That report
is available at www.alma.nrao.edu/committees/ASAC
as are other reports and minutes of that committee.  

There was some discussion of an earlier time than the current 1630 EDT.
The date of the next telecon will be Friday 23 May, 2003.  A 1600 EDT
time was suggested.