PowerPoint Presentation - Evaluation of the ALMA Prototype Antennas

January 3, 2006

ALMA Prototype Antenna Evaluation OverviewEvaluation Overview

Surface Stability

±Time Stability:

∞VertexRSI: < 10 mm RMS (May/June 2003)

∞AEC: ~ 5 mm RMS (February 2004)

±Ambient Temperature Stability:

∞VertexRSI: ~ 0.6-0.7 mm/K

∞AEC: ~ 0.8 mm/K


	For each measurement series the average of the series was subtracted from each map to eliminate long-term drift.
	For each measurement series maps were binned into 4-5 temperature ranges and averaged.
	Maps shown are temperature difference maps for each antenna scaled to a 10C temperature difference.
	Odd structure on AEC map likely due to frozen-in deformation resultant from elevation-runaway accident.