Al Wootten gave a summary of some points from the MMA Internal. They are as follows:

Imaging
It is expected that the MMA will often be used in an interactive observing mode. How important will it be to have on-line images? The general feeling seemed to be that a reliable pipeline will be essential for on-line programming decisions, early recognition of errors (wrong position, wrong LO, etc.), quick evaluation of date quality, etc. A pipeline will also be essential simply from the stand point of dealing with the enormous data rate that the MMA will produce. It is recommended that work on a reliable pipeline be started as soon as possible so that it will be available as an integral part of the on-line and early reduction software.

Configurations
Progress on modeling of the array configurations was noted. In particular, the D-array subconfigurations are still under consideration to satisfy maximum sensitivity with minimum shadowing and sidelobes for a range of observing requirements.

Phase calibration
The technique of choice is monitoring either the 22 GHz or the 183 GHz water line. A lot of work has been done on the 22 GHz line at OVRO and BIMA and there seems to be general agreement that monitoring this line would provide reliable phase corrections. The problem with this line is that its feed would fill a large fraction of the focal plane and its beam would probably be larger than the central hole in the primary dish. The 183 GHz line would not suffer from these problems but it has not been extensively tested as a phase calibrator. Plans are underway to do this at the Chilean site, but it will probably take until January at least to get the system set up.

Jack Welch has pointed out that the 183 GHz line might be problematic when clouds are present because of the frequency squared dependence of emission in the water lines.

Amplitude calibration
The main activity here is the search for new secondary calibration sources including: stars; solar system objects such as asteroids, moons, etc.; and a two-load calibration system. The goal is to achieve an accuracy of 1-5%.

Two corrections to the Internal Review report that Jean and I sent out last week:

1) A nutating subreflector is planned only for the two prototype antennae. A decision on whether all antenna will have one will depend on scientific requirements.

2) The prototype antennae will also be outfitted with 230 GHz receivers for testing at the VLA site in addition to the 30 and 90 GHz receivers.

Correlator
The present correlator design has a highest resolution at 230 GHz of 0.02 km/s with steps of two in bandwidth and corresponding decrease in resolution.

Receivers
The list of recommended receivers generated by Al Woottenıs committee was based on a study of the astrophysically most important atomic and molecular lines presently known and maintaining a frequency ratio of 1.30 or less.

Results of the meeting with the NSF Oversight Committee(Peter Napier)

1) The Chilean site was accepted by the committee.

2) The committee was enthusiastic about collaboration with the Europeans.

3) They want more detailed project management plans. In particular, more detailed budget, manpower, and scheduling plans.

4) Because of the desired delivery date of June 2001 for the first antenna, they have recommended that as much time as possible be given to the contractors to develop a satisfactory design. This means pushing the presentation to the contractors ahead as much as possible.

Richard Hills was concerned about altitude effects at 5000m and asked about the possibility of doing some tests by adding oxygen to a room at the site. Peter Napier said that tests are already being conducted in California by an expert on the physiological and psychological effects of altitude. He is testing human responses in a room whose air composition can be adjusted to mimic that of the atmosphere at a specified altitude.

We will have a MAC meeting this Fall. September is too soon to get onto calendars and October seems to be too busy with various meetings and some members have told me that the first weekend in Nov. is not possible for them. I am thinking of trying for the second weekend in Nov. I don't want to put it off any later than this if we can avoid it. Let me know if this is absolutely impossible for any of you. I still have to clear this NRAO and Iım sure we will not be able to fit everyone's schedule, but we will do the best we can.