July 26, 2006
ALMA Pointing
22
Pointing Performance
Summary
Offset
Absolute
Offset
Absolute
0.94
±
0.26
(spread)
±
0.05
(extrapolation)
±
0.20 (wind)
É
0.50
±
0.13
(spread)
±
0.02
(extrapolation)
±
0.11 (wind)
É
Accelerometer (15 min)
0.58
±
0.15
(spread)
±
0.08
(wind)
É
0.29
±
0.09
(spread)
±
0.05
(wind)
É
Accelerometer (10 sec)
<0.9
<4
<0.5
<4
Radiometric
0.3-1.1
1.3-1.8
0.3-0.8
2.0-2.6
Optical
VertexRSI (arcsec)
AEC (arcsec)
System/Technique
Spread = measurement spread, Extrapolation = wind power spectrum extrapolation uncertainty, Wind = Wind power spectrum uncertainty.