January 3, 2006
ALMA Prototype
Antenna Evaluation OverviewEvaluation Overview
30
ALMA Prototype Antenna Performance Summary
VertexRSI
AEC
(15,21,32)
mm*
(15,18,30)
mm*
15/20 mm (non-repeatable/repeatable)
Path
Length Stability
1.5-1.8
sec
1.4-1.8
sec
1.5 degree move in 1.5 seconds;
settle to 3 arcsec peak pointing error
Fast
Switching
0.3-1.1
arcsec*
0.3-0.8
arcsec*
0.6 arcsec over 2 degree radius
Offset
Pointing
1.3-1.8
arcsec*
2.0-2.6
arcsec*
2 arcsec
all-sky
Absolute
Pointing
16±5 mm
17±5 mm
25 mm RMS (20 mm goal)
Surface
Accuracy
Performance
Specification
Property
* Without
metrology
** Dt < (3,10,30) minutes