Sardinia Radio Telescope,
the VLBA and the HSA
Luigina Feretti
INAF Istituto di Radioastronomia
Bologna, Italy
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The Sardinia Radio Telescope
- Fully steerable dish, alt-azimuth mounting, Diameter: 64 m, 3000 tons
-Frequency range : 300 MHz – 100 GHz
-Actively controlled surface : 1008 panels,
1116 mechanical actuators
- Multiple focal positions : P, G, BWG
- Frequency agility
- State-of-art receivers (multi-beam)
- Digital back-ends
- Fiber optic connection
-Transmitting capability
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3
S. Basilio
Quality of the site:
Low
Low
Low
Low
rain
atm opacity
RFI
wind
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22 May 2010
Big Lift : 500 tons
30 May 2010
Quadrupode
Lift
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July 2010
January 2011
First light:
RECEIVERS
310-420 MHz
1.3-1.8 GHz
5.7-7.7 GHz
18-26 GHz
4 BANDs
BACK-ENDS
Primary focus
Digital Spectrometer
Pulsars
1 GHz BW, 1024 channels
Mono-feed
BWG focus
Spectrometer
60 MHz BW
Dual Band
Multi-feed
7 pixels
Gregorian focus
Total Power Analogic Back-end
7x2 outputs, 2 GHz BW
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Observing time (in %) with an expected atmospheric opacity τ<0.1
23.8 GHz 31.4 GHz 100 GHz (Ambrosini et al.)
(23.8 and 31.4 GHz measured, 100 GHz extrapolated)
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Radio Astronomy Science
●VLBI – eVLBI : x2 sensitivity up to 22 GHz
x5
at higher freq
mm-VLBI  43 GHz (7 mm)
 86 GHz (3 mm) [GMVA, ALMA]
● Italian VLBI
● Single dish
Space Science ASI (20%)
● Data down link
● Space science : Radio science, Deep Space Network
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VLBA + SRT
Several Groups use VLBA in Italy:
Bologna - low lum RS, young RS,
RS with gamma emission
Fi (Arcetri ) – Galactic Masers
Ca
and Megamasers
10
-20
10
40
70
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Sensitivity improvement
DEC= 30o
22 GHz : 27%
5 GHz : 45%
1.6 GHz : 45%
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HSA + SRT
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Full tracks
-20
30
10
60
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Sensitivity improvement
22 GHz : 10 %
5 GHz : 10 %  16 % (no Arecibo)
1.6 GHz : 8 %  15 %
“
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Future receiver : 43 GHz, dual feed (?)
Use of SRT :
ASI : 20 %
VLBI - eVLBI : EVN, Space VLBI, …
Single dish
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Thank you
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