Feb 2005

For SKADS Meeting, Amsterdam, 24 February 2005

Overview of Australia’s NTD/SKA Activities for Mileura in WA

Presented by: Colin Jacka and John O’Sullivan24 February 2005

www.atnf.csiro.auMileura Site

www.atnf.csiro.auMileura, Pathway to SKA

150km

Perth 850km

Geraldton ~500km

www.atnf.csiro.auWhat 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.auRadio 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.auSKA Demonstrator in Australia

NTD (New Technology Demonstrator) 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)

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.auRequirements 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

www.atnf.csiro.auOverlap 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

www.atnf.csiro.au

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 RF-testing program, and we have further collaboration with UWA/Curtin for xNTD tasks

www.atnf.csiro.auSummary 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

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

Maximum Baseline < 1000 m Full cross correlation all antennas Located in the RQZ at Mileura, Western Australia

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

www.atnf.csiro.auMNRF 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.auWhat difference does the x make?

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

www.atnf.csiro.auChallenges 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.auxNTD Work-break-down Task Groups

1. Antenna - dish and mount

2. Feed System – focal plane array

3. Data Transport – fibre optic

4. Local Oscillator and Control Signalling

5. LNA

6. Receiver

7. FPA Integration

8. Calibration, Control and Monitoring

9. Digital Signal Processing – filterbanks, beamformer, correlator

10. Offline Astronomy Software (actually “post-correlation” software)

11. Wide Area Network – data backhaul, remote observing

12. Site and Infrastructure – Australian SKA site

www.atnf.csiro.auNTD Antenna System

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)

www.atnf.csiro.auAntennas for Extended NTD (xNTD)

Proposed project to extend the collecting area of the NTD array to 64m dish equivalent (~ 20 dishes)

Based on NTD technology, but will explore options for increased bandwidth (1GHz) and operating band (to 2.4GHz)

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

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

www.atnf.csiro.au“Flat-pack” Reflector Concept

Images & antenna concept from Ross Forsyth

www.atnf.csiro.au(1) Reflector antenna options

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

www.atnf.csiro.auFleurs dishes

www.atnf.csiro.auFPA options

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

www.atnf.csiro.au

FPA system diagram

AD PFB

AD PFB

AD PFB

PFB

PFBbeam-former

Router

beam-former

Array element + integrated analogue receiver

Digital receiverRouter Beam-

former2nd stagefilterbank

To Correlator

www.atnf.csiro.auConclusions and next stages of work

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.

www.atnf.csiro.auReceiver

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)

www.atnf.csiro.auDigital Signal Processing

(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

NTD ― 2 (not 20) complex beamformers, but one simple buffer/correlator

Also, taking wider view, looking at next generation telco technology for the Routing problem.

www.atnf.csiro.auNTD/SKA Signal Processing

Beamformer Needed for first antenna Same for all antennas

Correlator 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.auBeamformer

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.auCorrelator

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

www.atnf.csiro.auHow

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

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

www.atnf.csiro.auPossible beamformer

16 channelPolyphase

Output 16x16MHzcomplex

16 channelPolyphase

Output 16x16MHzcomplex

~512 MS/s Real or~256 MS/s Complex

~512 MS/s Real or~256 MS/s Complex

Inputs from100 Vivaldi

feeds

RoutingnetworkOutputs16MHzall feeds

Beamformer~48 beam16 MHz

Beamformer~48 beam16 MHz

48 beams256 MS/s

(4R,4I) complex100 Gbits/s

to centralcorrelator andbeamformer

48 16MHz1k ChannelPolyphase

48 16MHz1k ChannelPolyphase

www.atnf.csiro.auPossible NTD correlator

8 antenna2 beam

Router andBuffer

8 antenna2 beam

Router andBuffer

8 antenna2 beam

Router andBuffer

Beam 1 HFRouter and data

serialiserXC4VFX20

Beam 2 LFRouter and data

serialiserXC4VFX20

Beam 2 HFRouter and data

serialiserXC4VFX20

Beam 1 LFRouter and data

serialiserXC4VFX20

HF CorrelatorBeam 1

2 x XC4VSX35

LF CorrelatorBeam 1

2 x XC4VSX35

HF CorrelatorBeam 2

2 x XC4VSX35

LF CorrelatorBeam 2

2 x XC4VSX35

LTAXC4VLX25

DDR2

DDR2 DDR2

LTAXC4VLX25

DDR2

DDR2 DDR2

Correlator BoardDual RocketI/O Links2x8 Gb/s

www.atnf.csiro.auReconfigured as MIT correlator

8 stations16 tiles

Router andBuffer

8 stations16 tiles

Router andBuffer

8 stations16 tiles

Router andBuffer

8 stations16 tiles

Router andBuffer

IntermediateRouter

8 MHz 5123 x XC4VFX20

(one of four)

Dual RocketI/O Links2x8 Gb/s

9 Rocket I/Ooutputs

0.888MHz

Router and dataserialiser

XC4VFX20

Router and dataserialiser

XC4VFX20

Router and dataserialiser

XC4VFX20

Router and dataserialiser

XC4VFX20

HF CorrelatorBeam 1

2 x XC4VSX35

LF CorrelatorBeam 1

2 x XC4VSX35

HF CorrelatorBeam 2

2 x XC4VSX35

LF CorrelatorBeam 2

2 x XC4VSX35

LTAXC4VLX25

DDR2

DDR2 DDR2

LTAXC4VLX25

DDR2

DDR2 DDR2

Correlator Board (one of 9 per Intermediate Router)

512 antennas

384 antennas

256 antennas to routers 2&3

www.atnf.csiro.auPost-correlation Processing

(Tim Cornwell)

Not just “off-line” software for xNTD Probably require extensive FPGA-based processing on-

line to reduce data enough for storage

Commonalities with MIT LFD

Resource budget! Anyone aware of case where

predicted effort > than actual effort?

www.atnf.csiro.auThe Panorama

Mileura means Can see a long way

www.atnf.csiro.auRFI Mission

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.

www.atnf.csiro.auRFI Measurements are under way

www.atnf.csiro.auRFI Measurements (2)

www.atnf.csiro.auNTD/xNTD Project Strategy