Numbers

ACA
12m Array
Array
From 5,000m to 5,100m
Altitude
12(7m) + 4 (12m)
50 (up to 64)
Number of Antennas
460 + 450 m2
5,650 m2
(up to 7,240 m2)
Total Collecting Area
5.7" (λ/1mm)
0.02" (λ/1 mm)
(10 km/distance)
Angular Resolution
15 - 16,000 m
Baseline Lengths
Antennas
7m, 12m
12m
Diameter
<20µm, <25µm
<25 µm
Surface Accuracy
<0.6", 2” all-sky absolute pointing under primary operating conditions
Offset Pointing
Correlator
120
up to 2016
Baselines
16 GHz per base line
Bandwidth
4096
Spectral Channels

The 10 Frequency Bands of the ALMA antennas

Receiver Technology
To be
produced
by
Temperature (K) at any RF Frequency
Receiver Noise (K) over 80% of the RF band
Frequency Range
(GHz)
ALMA Band
HEMT
tbd
26
17
31 - 45
1
HEMT
tbd
47
30
67 - 90
2
SIS
HIA
60
37
84 - 116
3
SIS
NAOJ
82
51
125 - 163
4
SIS
OSO
105
65
162 - 211
5*
SIS
NRAO
136
83
211 - 275
6
SIS
IRAM
219
147
275 - 373
7
SIS
NAOJ
292
196
385 - 500
8
SIS
NOVA
261
175
602 - 720
9
SIS
NAOJ
344
230
787 - 950
10

tbd:
to be decided
IRAM: Institut de Radio Astronomie Millimétrique (Grenoble, France)
HIA: Herzberg Institute of Astrophysics (Victoria, Canada)
NAOJ: National Astronomical Observatory of Japan (Mitaka, Japan)
NOVA: Nederlandse Onderzoekschool voor Astronomie (Groningen, the Netherlands)
NRAO: National Radio Astronomy Observatory (Charlottesville, USA)
OSO: Onsala Space Observatory/Chalmers University (Onsala, Sweden)
* EU FP6 receivers from Onsala