Download The SKAMP project - Australia Telescope National Facility

SKAMP
Square Kilometre Array Molonglo Prototype
Supporting Institutions
 University
of Sydney
 Argus Technologies
 ATNF
 ICT Centre
SKAMP Team
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Anne Green
Duncan Campbell-Wilson
John Bunton
Mike Kesteven
Tim Adams
Martin Leung
Sergey Vinagradov
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Bevan Jones
Andrew Parfitt
John Kot
Peter Liversidge
Daniel Mitchell
Adrian Blake
School of Physics, University of Sydney
Argus Technologies, Sydney
ICT Centre, CSIRO
Australia Telescope National Facility, CSIRO
SKAMP Specifications
Collecting area = 1% of SKA (i.e. equivalent to 1 SKA station)
 Multibeaming
 Wide instantaneous field
of view
 Digital beamforming
 Wide-band FX correlator
(2048 channels)
 Frequency and pointing
agility
 Line feed 0.3-1.4 GHz
>100 MHz instant BW
 Cylindrical antenna
prototype
 RFI mitigation
strategies - adaptive
noise cancellation
SKAMP Project
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Stage I: Continuum Operation
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Stage II: Spectral Line Operation
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New IF Samplers
Digital delay lines
Fringe tracking
Continuum correlator (96 station; 4 MHz)
New LO
New IF distribution
2048 channel polyphase filter/antenna;
Spectral line cross-correlator engine (50 MHz BW)
Stage III: Wide Band Operation
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Wide band feed (300-1400 MHz)
RF beamformers distributed along the cylinder
New front-end
Digital beamformer + increased correlator BW
SKAMP Development Groups
 Antenna/Linefeed
 Data Acquisition
AxB
& Beamforming
 Correlator
 Signal
Processing
Antenna/Linefeed Progress
AxB
Initial prototyping and simulation has
begun for possible linefeed designs
 Currently being investigated is a wideband
dipole antenna element
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 A three
element array has been constructed
and tested
 Several multi element arrays have been
simulated
Prototype antenna design
Farfield patterns for different y-offsets at 843 MHz (TM pol)
0
y offset = 0
y offset = 0.5 
y offset = 1.25 
-5
Amplitude (dB)
-10
-15
-20
-25
-30
-35
-15
-10
-5
0
 (degrees)
5
10
15
Simulation: Normalised Amplitude
 Eight Element Array
 Optimal choice of
spacing
 High polarisation purity
(-24 dB)
 Low level of sidelobes
Simulation: X-Polar Pattern
 Eight Element Array
 Optimal choice of
spacing
 High polarisation purity
(-24 dB)
 Low level of sidelobes
Data Acquisition & Beam-forming
Progress
AxB
100 x ADC boards manufactured & ready
to install
 Digital delay & phase-tracking board
currently being manufactured
 First fringes obtained
 Stage II – samplers, IF signal transport
and beamformers in design
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ADC Production & Testing
First Fringes
Correlator Progress
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Correlator design complete & PCB is current
being manufactured/populated
Testing & debugging will commence early July
Lab for testing established at USYD
Stage II – spectral line correlator design being
revised; several options for polyphase filterbank
AxB
Signal Processing Progress
AxB
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SKAMP I interface built and installed
 Controlled
acquisition of telescope parameters,
wide field position and visibilities every second
 From ephemeris package, computed delay, phase
and phase rates. Also calculation of telescope tilt
and meridian distance.
 Distribution of information to delay and phase
control units
 Imminent completion of data visibility formatting
and archiving
Summary
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Stage I:
 Commissioning August
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Stage II:
 Update
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– December 2004
design matrix
Stage III:
 Commissioning
eight element prototype
 Simulation of centre fed finite cylinder