Science IPT 25Jan2005

Wootten, Wilson, Kawabe, Vila-Vilaro, Lucas, Mangum, Zwaan, Emerson,Conway
Guilloteau, Dutrey, Holdaway, Wright, Richer, Hogerheidje, Stirling

positive response from EU for alma enhancement funding, 8 rx in band 5 plus
software support.  
RK: site selection of ACA location.  Of three candidates, W was selected.
Have revisited on the basis of new DEM.
ALMA-J science characterization plan.  ASTE involved in measurement with Holdaway.
Study on 10 micron camera and 220 GHz tipper.  Is the camera useful for 
dynamic scheduling.  U. Tokyo group now operating this at the ASTE site, only
as a test for now.  Will be moved for the TAO 4m optical ir telescope project.

Milestone--ancillary calibration devices group.  email discussion going on
about required meteorological devices.  Ideas fairly mature.  The ICD will
cover impact on site.  

Holo on both antennas.  This revealed several things--some bolts tightened on
Vertex had distorted the surface.  Another panel setting got it to the 15 micron
range.  AEC holo revealed a similar deformation due to feed leg attachent change.
Also found an error in the holography program, a 2cm offset in where panel
boundaries should be and where they showed up in holo maps, this resulted from
an incorrect assumption on ref point on structure for distance calc to transmitter
which gives near field correction.  This introduced a spherical aberration like
structure into the surface adding 12 microns in rms to the measurements.
May now reset surfaces, redo holography.
Radiometry on Vertex, oof beam maps and cuts.  This has been difficult as planets
are not well placed.  Need the small ones--Mars, Venus or Mercury which transit
at 33 degrees so elev dependent measurements difficult.  Nutator has also
caused problems.  OPT ON AEC antenna.
Photogrammetry on both antennas done last week.  Good results, agree with
holography.  This sensitivity is about 20 microns, also done as function of
elevation to measure astigmatism.

Quantization noise memo.  Science requirement 1dB across band.  Variation of
S/N across passband should not exceed 1dB.  This means that the gain variation
across the passband should not exceed 11dB total.  This memo will be submitted
as an ALMA memo.  That case is more complicated owing to the FIR filters, which
impose a second digitization, mathematically a convolution.  This will be
included in the ALMA specific second quantization.  

Configuration--Could save about 30 pads probably by going down to 50 antennas.
This would ease ops also.  Various documents contain inconsistencies but
site has not responded.  CALL SITE ON THIS AT NEXT IPT MEETING.
AOS building.  Where are the obstacles?

Software in good order.
Process should take about 6 weeks.

Feb and March JC is fairly free, teach for five weeks.

Calibration--amplitude device contract still under way.

SSR--continuing work.  Discussions upcoming.

Imaging--Mark discusses calibrator survey.  ten deg dec range +10-+20 would
give us 15% of the total sources, could be done in three to six weeks.  Monitoring
3000 bright sources in polzn and flux could provide an additional three weeks.
SMyers--plans to use other telescopes?  MH: For high frequency we could do some.

Next meeting 15 Feb