Transcript Add Title here - Square Kilometre Array

Feb 2005
Overview of Australia’s NTD/SKA
Activities for Mileura in WA
For SKADS Meeting, Amsterdam, 24 February 2005
Presented by: Colin Jacka and John O’Sullivan
24 February 2005
Mileura Site
www.atnf.csiro.au
Mileura, Pathway to SKA
www.atnf.csiro.au
Perth 850km
Geraldton ~500km
150km
What is Planned for Mileura?
 Mileura Widefield Array
 NTD/xNTD (CSIRO led) ― towards Australia’s SKA
 LFD (MIT Haystack led) ― Aperture Array 100-300 MHz
 Berkeley Array ― EOR experiment
 CSIRO (Ron Ekers et al) ― for EOR
 RQZ ― essential for all of the above
www.atnf.csiro.au
Radio Quiet Zone activities
 Working with Fed, State & Local govts towards establishing
procedures to protect the radio quietness and set up the
RQZ
 With ACA to control licensed transmissions
 Within 100-300 km coordination zone
 With WA Govt to control incidental transmissions via DAs
 Within 30 km development controls
 RQZ regulations apply only to fixed development & services
(not apply to mobiles, aircraft, emergency services, Defence)
 Signage for mobiles, coordination with Defence, aircraft
www.atnf.csiro.au
SKA Demonstrator in Australia
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NTD (New Technology Demonstrator)
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Funded by Australian government and CSIRO as one of the MNRF- (Major New
Research Facility) funded projects over the period 2002 – 2007
Until June 2004, most of effort was on Luneburg Lenses
From July 2004, the effort is associated with using Focal Plane Arrays (FPAs)
Due for completion in July 2007
2 dishes fitted with Focal Plane Arrays at the Australian candidate SKA site at
Mileura in Western Australia (~ 26° 37' S, 117 ° 29.5' E)
xNTD (Extended New Technology Demonstrator)
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Builds upon the designs & deliverables from the NTD
Extra funding obtained from CSIRO, 2005 – 2008
We now have the funding, but will not decide if xNTD is technically feasible until
Dec 2005, dependent on NTD progress in mitigating the technical risks
$25m AUD, 2005 – 2008, 20 dishes with FPAs, at Mileura site
A useful telescope in itself
But a vision for xNTD to evolve into technology for SKA
www.atnf.csiro.au
SKA Technology Developments at CSIRO
 Focal Plane Arrays
 Antennas
 Digital Processing
 Receiver Designs
 Software Systems
 High-speed networking
www.atnf.csiro.au
Requirements from MNRF Grant
 Stated aims at 2002 MNRF initiation:
 To develop multi-beaming antenna technology
 Advanced optical signal transport
 Advanced signal processing schemes
 Developing interference mitigation techniques
 Integrated into an operating instrument which would
benefit the development path towards the SKA
 Would make use of project deliverables from other
MNRF-funded projects eg CABB, MMIC, SKA Siting
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Overlap of xNTD and LFD
 Infrastructure and radio-quiet zone site
 Complementary frequency ranges
 Wide field of view science
 Technology behind the antennas
 Software
 Digital Hardware using FPGAs: (reconfigurable design
structures)
• LFD Receiver and NTD Beamformer
• Correlators
 Signal Distribution
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Establishment of Mileura site for Radio
Science in WA
 Technology, and a range of Radio Science
 WA Govt support for the Infrastructure
 WA Govt support for planning controls and
negotiations with the traditional owners
 WA Fellowship in Radio Astronomy is being
established
 CSIRO is collaborating with Curtin Uni on the RFtesting program, and we have further collaboration
with UWA/Curtin for xNTD tasks
www.atnf.csiro.au
Summary of Science with xNTD
 xNTD is ideal for large-area surveys and has good surface
brightness sensitivity. It is highly competitive with
current/planned instruments
 New science can be done with the xNTD if the specs /
technical challenges can be met.
 The xNTD is on the pathway to the SKA
 can add more and more collecting area
 One-day workshop planned for early 2005
 Engage and excite the entire astro community
 Improve the xNTD science case
www.atnf.csiro.au
xNTD Parameters
www.atnf.csiro.au
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Area = 4000 m2 (20 dishes, 180 baselines)
Tsys = 50 K
Frequency range = 0.8 – 1.8 GHz
Bandwidth = 256 MHz
Number of independent beams = 48
 each beam 1 sq deg  48 sq deg FoV at 1.4 GHz
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Maximum Baseline < 1000 m
Full cross correlation all antennas
Located in the RQZ at Mileura, Western Australia
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ATA - A=10000m2, FoV=5.5 sq deg, BW=1GHz, Tsys=50K
Parkes MB – A=3200m2, FoV=0.8 sq deg, Tsys=22K
ATCA – A=1900m2, FoV=0.6 sq deg, Tsys=30K
Arecibo – A=70000m2, FoV=0.02 sq deg, Tsys=35K
MNRF Progress to date
 Original NTD Project Plan
 Choose NTD concept by 30 June 2004
 Choice became one of selecting from
• Luneburg Lenses
• Cylinders
• Focal Plane Arrays
 Until June 2004, most effort was on Luneburg Lenses
 From that point on, the effort is on FPAs
• Revised Preliminary NTD Project Plan 30 September 2004
• Present Plan caters for a number of scenarios in an ever-changing
environment
• Now, have decoupled the 2 Project Plans
www.atnf.csiro.au
What difference does the x make?
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 NTD
 Funded by existing, secured ATNF + MNRF funds
 2 interconnected dishes, 15m diameter, each with focal
plane array, at proposed SKA site
 xNTD
 Additional funding from CSIRO & State Gov
 20 dishes, 15 m diameter, arranged in one group, genuine
micro-SKA, at proposed SKA site
 Project Plan: Design & Development Program until Dec
2005 is common for NTD and xNTD
 xNTD implementation phase from Jan 2006, as a result of
sufficient risk mitigation in areas of antenna, FPA, digital
beamforming and correlator design
Challenges for xNTD
 Can we make small steerable dishes cheap enough?
 Cheap, high performance (wide band and polarization pure)
FPAs?
 Cheap, high performance integrated RXs?
 No self-generated RFI from RXs (or rejection schemes)?
 How to transport signals from FPA?
 DBF (efficient, cost-effective using FPGAs)?
 Calibration with synthesized varying beam patterns?
 Correlator (a very large effort)
 Data storage & transportation
 Remote operation as a NF from East Coast of Oz?
www.atnf.csiro.au
xNTD Work-break-down Task Groups
1.
2.
3.
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5.
6.
7.
8.
9.
10.
11.
12.
Antenna - dish and mount
Feed System – focal plane array
Data Transport – fibre optic
Local Oscillator and Control Signalling
LNA
Receiver
FPA Integration
Calibration, Control and Monitoring
Digital Signal Processing – filterbanks, beamformer, correlator
Offline Astronomy Software (actually “post-correlation” software)
Wide Area Network – data backhaul, remote observing
Site and Infrastructure – Australian SKA site
www.atnf.csiro.au
NTD Antenna System
www.atnf.csiro.au
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Presently looking at 3 alternatives to meet the challenge of
performance/cost
 The Indian PPD dish design
 New design using manufacturing techniques available in Australia
 Refurbishing 2 antennas from Fleurs (for NTD)
Antennas for Extended NTD (xNTD)
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Proposed project to extend the collecting area of the NTD
array to 64m dish equivalent (~ 20 dishes)
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Based on NTD technology, but will explore options for
increased bandwidth (1GHz) and operating band (to 2.4GHz)
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Shares infrastructure and software development with
proposed MIT Mileura Wide-field Array Demonstrator (LFD)
www.atnf.csiro.au
(1) Indian PPD Reflector Prototype
Photos from Ken Skinner of SES
www.atnf.csiro.au
(2) Reflector antenna options
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 Custom-built mesh reflector using NC machine tools
 “High-tech” solution with high accuracy, good repeatability, and
no tooling-up costs
 Local manufacture of prefabricated “flat-pack” reflector;
assemble on site
 Changing the geometry, e.g. offset or larger f / D, no problem
 Estimated reflector mass significantly < PPD
 Estimated cost > current PPD estimate
“Flat-pack” Reflector Concept
Images & antenna concept from Ross Forsyth
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(1) Reflector antenna options
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 Refurbished dishes from the former Fleurs
radiotelescope
 Two 14m dishes in apparently good condition still exist at the
Fleurs site (close to Badgery’s Creek, Sydney).
 Estimated cost of transport + refurbishment ongoing
 Equatorial mount – advantageous for simple FPA
Fleurs dishes
www.atnf.csiro.au
FPA options
www.atnf.csiro.au
 Collaborative development of “Vivaldi” array with ASTRON /
U.Mass.
 Best option for short-term demonstrator
 Tested wideband array technology
 Limited operating band for SKA
 Relatively complex manufacture
 Alternate wideband arrays
 Looking towards the longer term to SKA
 Inherently wideband structures
 Foveated array with “natural” scaling of FoV
FPA system diagram
www.atnf.csiro.au
A
A
Array element +
integrated analogue
receiver
PFB
D
PFB
D
PFB
Digital receiver
beamformer
PFB
Router
A
D
To
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Correlator
beamformer
Router
Beamformer
PFB
2nd stage
filterbank
Conclusions and next stages of work
www.atnf.csiro.au
 Initial modelling of reflector + FPA system show that the NTD goals
for FoV and operating frequency band are achievable using
available technology.
 Next stages:
 Collaborative development with e.g. U. Mass. towards prototype NTD
FPA
 Ongoing system optimization study across reflector optical system, FPA,
front end & ADC
 System integration of FPA, analogue and digital electronics:
“plumbing”, self RFI, power, thermal, structural, mechanical
engineering.
Receiver
www.atnf.csiro.au
 200 RXs per dish
 RF-CMOS chip from MIMIC project (Suzy Jackson)
 Re-spec’d for NTD/xNTD requirements
 MIMIC for xNTD, but
 For NTD: perhaps part of MIMIC chip, and separate backend
 ICTC doing alternative backup discrete design for early
requirements
 Separate LNA for Tsys requirements (Paul Roberts)
Digital Signal Processing
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(John Bunton)
Each dish produces 200x256x106x2x8 ~ 1 Tera bps
Evaluate possibilities for commonality between
xNTD/LFD/CABB/ATA requirements
 Strong collaboration with MIT group; good interchange of ideas
between CSIRO and MIT
 White Paper developed at end of Dec 04
 Inter-site extended visits of MIT/CSIRO personnel
 Buffer, beamformer, correlator
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NTD ―
 2 (not 20) complex beamformers,
 but one simple buffer/correlator
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Also, taking wider view, looking at next generation telco technology
for the Routing problem.
www.atnf.csiro.au
NTD/SKA Signal Processing
 Beamformer
 Needed for first antenna
 Same for all antennas
 Correlator
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Complexity proportional to (no. antennas)2
Very simple for NTD
Comparable to beamformer for xNTD
Huge task for the SKA
 Image formation
 Currently software only
 May need hardware accelerators
www.atnf.csiro.au
Beamformer
 Two polarisations
 100 feeds per polarisation
 Each feed 250 MHz
 Total data rate 250MHz x 2samples/Hz x 2 pol x 100 feeds
 About 100 Gsamples/s
 Beam generated as weighted sum of signals from feeds
 BUT weighting is frequency dependent
 Filter signals to get correct weighting
 Or divide and conquer (filterbank) – narrow band
approximation
 Each feed contributes to ~10 beams
 Minimum 10 arithmetic operations/sample/beam
 100 GSamples/s x 10operation/sample/beam x 10 beams =
10 Tera operations/second !!! Per antenna
www.atnf.csiro.au
Correlator
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Must form a product between each pair of antennas signals
xNTD has 20 antennas x 2 pol = 380 different correlation
48 beams each 250 Mcomplex samples/s
7 operations per correlation
250x7 Moperations/correlation x 380 correlation x 48 beams
= 32 Tera operations/sec
 SKA 250 times as many antennas, twice the bandwidth
 Task is 125,000 times harder
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How
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 FPGAs
 Have 200 18bit multipliers adder@ 500MHz gives
 200 Giga operations/s in a single package (50 per antenna)
 Development in VHDL – reusable firmware
 But still need to be smart in how we do the processing
otherwise 10 Teraops/s goes to 100
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 High power autorouters 1000 of pins, route diff pairs for
high speed interconnects
 Without smart design the routing of the data will
strangle the design
Possible beamformer
~512 MS/s Real or
~256 MS/s Complex
16 channel
Polyphase
Output 16x16MHz
complex
Inputs from
100 Vivaldi
feeds
~512 MS/s Real or
~256 MS/s Complex
16 channel
Polyphase
Output 16x16MHz
complex
www.atnf.csiro.au
Beamformer
~48 beam
16 MHz
48 16MHz
1k Channel
Polyphase
Routing
network
Outputs
16MHz
all feeds
Beamformer
~48 beam
16 MHz
48 16MHz
1k Channel
Polyphase
48 beams
256 MS/s
(4R,4I) complex
100 Gbits/s
to central
correlator and
beamformer
Possible NTD correlator
Dual Rocket
I/O Links
2x8 Gb/s
8 antenna
2 beam
Router and
Buffer
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Correlator Board
Beam 1 HF
Router and data
serialiser
XC4VFX20
HF Correlator
Beam 1
2 x XC4VSX35
DDR2
DDR2
LTA
XC4VLX25
8 antenna
2 beam
Router and
Buffer
Beam 1 LF
Router and data
serialiser
XC4VFX20
LF Correlator
Beam 1
2 x XC4VSX35
Beam 2 HF
Router and data
serialiser
XC4VFX20
HF Correlator
Beam 2
2 x XC4VSX35
DDR2
DDR2
DDR2
LTA
XC4VLX25
8 antenna
2 beam
Router and
Buffer
Beam 2 LF
Router and data
serialiser
XC4VFX20
LF Correlator
Beam 2
2 x XC4VSX35
DDR2
Reconfigured as MIT correlator
8 stations
16 tiles
Router and
Buffer
Dual Rocket
I/O Links
2x8 Gb/s
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9 Rocket I/O
outputs
0.888MHz
Intermediate
Router
8 MHz 512
3 x XC4VFX20
(one of four)
8 stations
16 tiles
Router and
Buffer
512 antennas
Correlator Board (one of 9 per Intermediate Router)
8 stations
16 tiles
Router and
Buffer
Router and data
serialiser
XC4VFX20
HF Correlator
Beam 1
2 x XC4VSX35
DDR2
DDR2
LTA
XC4VLX25
8 stations
16 tiles
Router and
Buffer
Router and data
serialiser
XC4VFX20
LF Correlator
Beam 1
2 x XC4VSX35
DDR2
256 antennas to routers 2&3
Router and data
serialiser
XC4VFX20
HF Correlator
Beam 2
2 x XC4VSX35
DDR2
DDR2
LTA
XC4VLX25
384 antennas
Router and data
serialiser
XC4VFX20
LF Correlator
Beam 2
2 x XC4VSX35
DDR2
Post-correlation Processing
 (Tim Cornwell)
 Not just “off-line” software for xNTD
 Probably require extensive FPGA-based processing online to reduce data enough for storage
 Commonalities with MIT LFD
 Resource budget!
 Anyone aware of case where
predicted effort > than actual effort?
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The Panorama
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Mileura means Can see a long way
RFI Mission
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Characterize RF Spectrum 50MHz-24GHz
High Sensitivity
Fine Temporal Resolution
Fine Frequency Resolution
All directions
Both orthogonal polarizations.
Noise source calibration
Period 1 year.
~Terabyte of data
Demonstrate application of Solar power.
Collaborate with WA Govt and Curtin Uni.
RFI Measurements are under way
www.atnf.csiro.au
RFI Measurements (2)
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NTD/xNTD Project Strategy
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