MMA Imaging and Calibration Group
Supplement to agenda for meeting Tuesday, 29 Oct 2002 at 4:00pm EDT.
The ALMA Antenna Transporter
The Transporter Concept in Motion (Image courtesy Nicolas Emerson
based on a design of Max Kraus at ESO.)
The transporter does pose several concerns.
In moving through the compact array to remove an antenna, it clears
antennas to the side of it which are locked onsite and pointed away from
its path by only 1.2m. Is this good enough? What might the effect of an
unfortunately timed earthquake be? Recall that a tremor at the OVRO array did
result in the 'seige tower' hitting an antenna once. As described, the
transporter traverses the path to the antenna guided by GPS devices,
probably aided by TV cameras and perhaps guidelines on the ground. The
cabin is oxygenated.
The transporter plucks the antenna from the foundation without moving
over it, an admirable quality. Is the foundation really stable to the approach
of the transporter/antenna combination?
One operations plan has the transporter moving four antennas every fourth
day.