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The UniBoard Requirement
In Shanghai Astronomical
Obeservatory
X. Z. Zhang, Y. Xiang, R.J. Zhu, Z.J. Xu, Y. J. Wu,
J. T. Luo, W. Yu , S.G. Guo , B.J. Zhang
Shanghai Astronomical Obeservatory
UniBoard Meeting Oct 12-13, 2010
Outline
1.
Background
2.
New Correlator
3.
Digital Backend for Shanghai 65
meter
4.
Questions
Background
a)
Chinese VLBI Network needs a
powerful e-VLBI Correlator.
b)
The Digital Backend for Shanghai 65
meter antenna
c)
A powerful、low power consumption、
compact Platform is requited
Chinese VLBI Network (CVN)
2158Km
3249Km
1114Km
2476Km
2460Km
1920Km
65M
2012
Main Specifications of CVN Correaltor
Main Specification of CVN Correaltor:
Stations:
16
Bandwidth per Station:
2 ~ 4 GHz
Channels per Station:
16
Data Input : Mark 5， e-VLBI (network)
Data Input Format : VSI ，VDIF …
Data Outport Format : FITS，CVN
Applications:
Astrophysics
Astrometry
Geodesy
Spacecraft Tracking
Receiver specification for New Telescope
Band
“L”
Wavelength
“S” [4]
“C”
“X” [4]
“Ku”
“K”
“Ka” [4]
“Q”
9mm
7mm
Freq (GHz)
18
& 13cm
5 & 6cm 3.6cm
2.2cm
1.3cm
21cm
1.25-1.75 2.15-2.45 4.50-7.00 8.00-9.00 12.0-15.5 18.0-26.5
30-34
40-46
BW (GHz)
0.50
0.30
2.50
1.00
3.50
8.50
4.00
6.00
BW/CF (%) 33
13
43
12
25
38
13
14
T(Sys) (K)
22
24
26
25
27
46
38
66～108
T(Sky)(K)[1] 12
12
10
10
12
25
13
26～68
T(Rx) (K)
10
12
16
15
15
21
25
40
Feed Type
Conical
Conical Conical
Conical
Conical
Conical
效 率
Compac Conical
t
0.6[2]
0.6[2]
0.6[2]
0.55[2]
0.2[2]
0.5[3]
0.45[3]
极 化
Lin&Circ
Refrigerator 1020
双园
350
Lin&Circ
350
双园
350
0.4[2]
双园
350
双园
350
[1] Refer to EVLA data.
[2] Main reflector without active surface, 600 micron RMS surface accuracy.
[3] Main reflector with active surface, 300 micron RMS surface accuracy.
[4] S/X-band dual frequency receiver, X/Ka-band dual frequency receiver.
双园
350
双园
350
Digital Backend for Shanghai 65 meter Telescope
Main characteristic

VLBI Observation

Single Antenna Observation

Multi-Beam Observation
VLBI Observation
DBBC ：
Input:
4 IFs ，Bandwidth ：2 ~ 4GHz / IF
Output :
sub-channels：32
Band width of sub-channel ：0.5 ~ 64MHz
Bits of sub-channel ：1 、2 、4 、8bits
Data interface ：VSI 、VDIF
Single Antenna Observation
Line observations

Spectroscopic backend. High sensitivity and good
spectral resolution ，50Hz in 32MHz bandwidth
Continuum observations

Same as VLBI DBBC
Pulsar observations

Incoherent de-dispersion
Coherent de-dispersion
Multi-Beam Observation
There are 7 beam system on Shanghai 65 meter
telescope. We need a Beam-former for system.
A high powerful、low power consumption and
compact Platform will be selected.
The UniBoard should be a good selection for the
hardware platform.
The Plans
For digital backend:

Year 2010~2011 ， hardware develop and
firmware development

Year 2012，bandwidth 512MHz version work
on new telescope

Year 2015，bandwidth 2/4GHz version
completed
For Correlatter:

Year 2012， should be in operating
Questions
1.
The status and develop plan of UniBoard-1?
2.
The possibility to use more Boards in
SHAO?
3.
The possibility to shared IP for astronomical
application?
Thanks