ALMA Strawperson Donut/Double-Ring E Array

Physical Descriptions:

  1. Maximum baseline 150 m
  2. Minimum baseline 15 m
  3. Maximum near-in sidelobe 4%
  4. Maximum sidelobe inside PB in a snapshot is 10.9%

Pad Positions:

Pad positions are given here in meters. The X and Y positions are with respect to a reference position on the 5 degree mask. To convert to SAM56 coordintes:

SAM56 E = 624820 + X

SAM56 N = 7449700 + Y

Array Layout, UV Distribution, Synthesized Beam:



(Upper left panel) Pad distribution shown with the "5 degree slope" mask in red. Finding a patch of clear 150 meter diameter area is relatively easy. Four "gates" into the inner antennas are designed in for the ease of service and reconfiguration. (Upper right panel) Snapshot UV distribution and pad postions from CONFI. (Lower left panel) Snapshot dirty beam. The plotted color ranges between -5% (blue) and +10% (red). (Lower right panel) Radial density distribution of the visibility points for a snapshot observation. Nearly 50% of the UV cells are sampled instantaneously.