European Developments�for the�Square Kilometre Array

Steve Torchinsky�USN/GEPI Observatoire de Paris

SKADS Project Scientist

www.skads-eu.org

S.A. Torchinsky 1

European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Overview

• SKA Timeline
• SKA Key Science
• SKADS: European SKA Developments
• Science simulations
• Design and Costing
• Hardware demonstrators

​

S.A. Torchinsky 2

European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

SKA timeline

06 | 08 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 |

SKA-high Construct

External Engineering Review of design

Pathfinder implementation

SKA-mid+low

Complete

Phase 1 funding request

System design SKA-hi

Pathfinder operations

Phase 1 complete

Concept design & for SKA-high

Prod. Readiness Review

Early Science SKA mid+low

SKA Ops

Phase 2 funding request

Phase 1 Construction

US TDP

SKADS

SSEC Site

Rec

Mobilisation Infra Plan’g

Concept Design

System Design

Full SKA mid + low construction and commissioning

Detailed Design, Prod. Eng. &Tool’g

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

SKA Key Science

?

Tests of gravity

Epoch of Reionisation

Cosmic Magnetism

Cradle of Life

Large Scale Structure

Transient Universe

The Unknown

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

SKA Science Book

Chris Carilli & Steve Rawlings,

New Astronomy Reviews, Vol.48, Elsevier, Dec. 2004

​

http://www.skads-eu.org/p/SKA_SciBook.php

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Cosmology, Galaxy Formation

and Astroparticle Physics on

the Pathway to the SKA

Hans-Rainer Klöckner, Steve Rawlings,

Matt Jarvis, Angela Taylor (eds.)

Cosmology, Galaxy Formation and Astroparticle Physics on the Pathway to the SKA

Available online:

www.skads-eu.org (click “astronomy” and “LOSKA2006”)

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Simulations for the SKA

image by D. Obreschkow

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Simulations for the SKA

Effort in SKADS:

• Catalog of continuum sources�(250 Million sources)
• Epoch of Reionisation�(tomography from z≈15 to z≈6)
• The Cosmic Web
• Pulsars

​

• See SKADS Simulated Skies website
• www.skads-eu.org/p/s-cubed.php
• See SKADS publications
• www.skads-eu.org/p/memos.php

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Probing the Dark Ages

• Modeling and simulations of the Epoch of Reionisation at Obs de Paris

Di Matteo et al

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

SKADS Simulated Skies

s-cubed.physics.ox.ac.uk

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

SKADS Simulated Skies

www.skads-eu.org/p/s-cubed.php

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

SKADS Publications

www.skads-eu.org/p/memos.php

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

SKADS Science and Technology

The Universe

Our understanding of the Universe

Sky Simulation (DS2T1)

Convolution with the telescope (DS2T2)

Network simulator (DS3T3)

Technology development �(DS4)

Technology demonstrators�(DS5 & DS6)

observations

brain power

voltages

measurements�and�simulated performance

Backend data

Data imaging�(DS2T2)

Simulated telescope image

Request spec change�BENCHMARK

Catalogs, images, EM fields

Data analysis (DS2)

science goals achievable?

Consider trade-offs

SKADS�Design & Costing

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

SKA Design and Costing

• SKADS final deliverable “Designed and Costed SKA”
• First memo: detailed design
• www.skads-eu.org/p/memos.php
• SKA Memo #93
• ~1.5BEuro
• Development of costing tool: SKACost
• Designed and costed components and subsystems
• Data base for costing different SKA implementations
• SKADS in collaboration with International SKA Program Office

​

S.A. Torchinsky 14

European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Training the next generation

• 1^st MCCT School�Medicina 23-29 Sept 2007
• Wide field imaging and calibration�Groningen 2-7 March
• Synergies with the SKA�Bonn 14-18 April 2008
• Deep Field Imaging with SKA�Cambridge 25-29 Aug
• Radioastronomy and the New Instruments�Siguenza 27 Aug – 4 Sept
• Multifield and multibeam science with SKA�Oxford 15-27 March 2009
• Increasing the evolution rate in radio astronomy�Paris 24-28 August 2009
• Towards 3^rd generation calibration�Nançay 27 Sept – 10 Oct

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Possible SKA Configuration

Station

Core ~5km dia

Central

Processing

Facility

Comms links

Not to scale!

180km

Dishes spread

along spiral

Dishes

AA-hi

AA-lo

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Three Technologies

• ~5km inner cores
• sparse aperture arrays (eg. LOFAR)
• dense aperture arrays (eg. EMBRACE)
• parabolic dishes
• Outer core ~5km of stations
• Arms > 5km of stations
• dishes spread out along spiral arms
• maximum baseline of ~3000km

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Hardware Demonstrators

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

2-PAD: All Digital Aperture Array Demonstrator

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

2-PAD

• Developed in UK (Manchester, Oxford, Cambridge)
• Goals:
• Dual polarisation, all digital aperture plane array
• Demonstrate all-digital beam forming
• Process 100MHz bandwidth instantaneously
• Demonstrate cost-effectiveness of all-digital solution

​

S.A. Torchinsky 20

European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

EMBRACE

• Electronic MultiBeam Radio Astronomy ConcEpt
• Follows from pioneering developments at ASTRON
• Aperture-Plane phased-array
• 500MHz – 1500MHz
• Linear polarisation
• 160m² at Westerbork
• 90m² at Nançay

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

EMBRACE Overview

External Correlator

Interface

Analog Outputs

20 MHz wide

RF bandwidth

500 MHz to 1500 MHz

(400 MHz to 1600 MHz)

Mark V

Recording terminal

Ethernet

2 x 1 Gb/s

Recording cluster

Post processing

Ethernet

4 x 1 Gb/s

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

EMBRACE beams

Tile antenna pattern

Element antenna

pattern

Synthesized beams

RF beamforming at the tile level

​

Tile RF beams: sum of 64 phase shifted element antennas outputs, using RF beamformer chips (phase step 45°, 4 elements, 2 RF outputs)

​

Rough estimate of HPBW (λ/D):

HPBW @ 1 GHz: ~17.2° for one tile

HPBW @ 1 GHz: ~ 8.6° patch of 4 tiles

Digital beamforming at the station level

​

Synthesized beams: sum of all RF beams phase shifted, using digital signal processing

​

Rough estimate of HPBW (λ/D):

WATS HPBW @ 1 GHz: ~1.01°

NATS HPBW @ 1 GHz: ~1.72°

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

EMBRACE at Westerbork

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

EMBRACE at Nançay

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

EMBRACE at Nançay

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Station Digital Processing

Amplitude

Phase

Phase shift ≈ true time delay

only in narrow bandwidth

=>

​

Apply phase shift beamforming

on subbands

RF beam 1

RF beam 2

RF beam 3

RF beam N

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Nancay Beam Former Chip

NXP

BiCMOS 0.25 µm

SiGe process

QUBIC4G

2.27*2.27 µm²

^{including saw lines}

3 bits 360°

3 bits 5 dB

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Analog Beam Forming�on a Chip

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Nançay Micro electronics

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Nançay Beamformer Chip

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Data Flow

Antenna data

From RCU

​

2N x 200 Ms/s

12 b.

Correct for

Calibration

Nulling of

Interferers

Calculate

Calibration

Detect

Interferer

Calculate

Projection

Matrices for nulling

Subband

frequency

Array geometry

Subband

frequency

Array geometry

Source coordinates

Interferers coordinates

Station Control Unit

Subband

To be processed

Output mode

Time stamp

LO1 beam A

LO1 beam B

LO2

Data recording

Post processing

Local

Control

Unit

N cells of

combined tiles

2 RF beams

Store

Store

Store

Tile array

settings

Source coordinates

Mark V recording

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

digital data flow

Digital beam = sum of all phase shifted antenna data to point at source position φ

​

Phase shift = true delay only at one frequency => digital beamforming in narrow bandwidth

​

Subband width: 195.3125 Khz at 200 Ms/s (156.25 KHz at 160 Ms/s for LOFAR LBA)

2 data flows

X and Y

(12b. real)

512 X subbands

512 Y subbands

2 polyphase filter

banks

16 K coef.

Subband Select map

216 X subbands

216 Y subbands

Weights

216 X weights

216 Y weights

512 x

[Xre + jXim]_b

[Yre + jYim]_b

b = 0 to 511

(18b complex)

216 x

[Xre + jXim]_s

[Yre + jYim]_s

s in [0, 511]

(18b complex)

216 x

[X’re + jX’im]_s,φ

[Y’re + jY’im]_s,φ

s in [0, 511]

(18b complex)

1024 samples time frame =>

216 x

[XSre + jXSim]_s,φ

[YSre + jYSim]_s,φ

s in [0, 511]

(16b complex)

(N-1) x 216 x

[X’re + jX’im]_s,φ

[Y’re + jY’im]_s,φ

s in [0, 511]

(18b complex)

Data flow (digital bandwidth) =>

7.2 10⁹ b/s

3.0375 10⁹ b/s

3.0375 10⁹ b/s

2.7 10⁹ b/s

Max[nb.s]

= 216

Max[nb.s x nb.φ]

= 216

Max[nb.s x nb.φ]

= 216

Constraints =>

Station digital beam = collection of [XSre + jXSim]_s,φ for the required number of subbands s and one φ

One tile or cell

of combined tiles

Station

output

From LCU (1s time frame)

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

EMBRACE Backend

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Low Noise Amplifiers at Nançay

Cascoded topology single-ended

Process

0.25 µm SiGeC

Fondary QUBIC4X

NXP Caen

Consumption

Idc = 15 mA

Vcc = 3.3 V

OIP3 = 9 dBm

P_-1 dB = -1 dBm

Input and Output

50 Ohms Single-Ended

Matching

Surface = 0.5 mm²

LNA layout

0.6

0.7

0.8

0.9

1.0

1.1

0.5

0.7

0.9

1.1

1.3

1.5

1.7

Frequency GHz

NF dB10 simulation

NF dB10 measure

T_amb = 295 K

Frequency GHz

T_amb = 295 K

S₂₂ dB measure

S₁₁ dB measure

S₂₁ dB measure

S₂₁ dB simulation

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

EMBRACE prototype�observations of the Sun

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European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

EMBRACE Characterisation

• Characterisation of the full array at Westerbork expect to begin in September. Nançay will soon follow.

S.A. Torchinsky 37

European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

People involved in France

• System Design & Implementation
• Philippe Picard
• William Paule
• Micro electronics
• Jacques Pezzani
• Stéphane Bosse
• Severin Barth
• Guy Kenfack
• Bruno da Silva
• System Software
• Patrice Renaud
• Christophe Taffoureau
• Simon Pomarède
• Jean Borsenberger
• RFI Mitigation strategies
• Pierre Colom
• Rodolphe Weber
• Rym Feliachi
• Cédric Viou

• Infrastructure
• Ivan Thomas
• Simulations of EoR
• Françoise Combes
• Paola di Matteo
• Benoit Semelin
• Sunghi Baek
• Yves Revaz
• Testing & Astronomical Observations
• Steve Torchinsky
• Henrik Olofsson
• Laurent Chemin
• Wim van Driel
• Jean-Michel Martin
• François Viallefond
• SKA-France Coordination
• Wim van Driel
• EU Management Team
• Steve Torchinsky

• Other associated scientists
• Chantal Balkowski
• Albert Bosma
• Patrick Charlot
• Ismael Cognard
• Nicole Cornilleau
• Katia Ferriere
• Eric Gérard
• Stéphane Guilloteau
• Thibault Lebertre
• Matt Lehnert
• Gilles Theureau
• And you!

S.A. Torchinsky 38

European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009

Contact

Steve Torchinsky

SKADS Project Scientist

USN/GEPI, Observatoire de Paris

Phone: +33 1 45 07 75 02

Email: Steve.Torchinsky@obspm.fr

Web: http://www.skads-eu.org

S.A. Torchinsky 39

European Developments for SKA

4^th Sino-France, Tongling, 23 July 2009