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PrepSKA
•
A Preparatory Phase Proposal for the Square Kilometer Array radiotelescope
•
EU - FP7
•
Domingos Barbosa, Paulo André, Luis Cupido (IPFN-Aveiro)
Agências: STFC (Reino Unido), NWO (Holanda), CNRS (França), INAF (Itália), DIISR (Austrália), NRF (África do Sul), NRC-HIA (Canadá), CSIRO (Austrália)
Institutos: U. Manchester (Reino Unido), Max Planck (Alemanha), Instituto de Telecomunicões (Portugal),
U. Cambridge (Reino Unido) , U. Oxford (Reino Unido), U. Cornell (EUA) , JIVE(Europa), Obs. Paris (França) , U. Calgary (Canadá), U.Groningen (Holanda)
Outras Instituições participantes: National Science Foundation (EUA), Associated Universities Inc (EUA), Fundacion General de la Universidad de Alcala/Instituto Geografico Nacional (Espanha), Vetenskapsradet (Suécia), SKA Programme Development Office (Global).
Orçamento : 22Meuros ; 5.5Meuros FP7
Simulations for the SKA
•
Objectivos : sondar um cone do Universo de cerca 12 mil milões
anos.
On
behalf
of
Phil
Diamond
•
Build
over
SKADS FP6•
FP6 –
Design
Stdudies; FP7 –
Preparory
Phase; FP8 -
Construction
ISPOIntroducing SKA
Aperture synthesis radio telescope with 1 km2 of effective collecting area by 2020
4000 antennas; 200 stations; 3000 km
50x sensitivity, 10 000x survey speed of existing arrays Frequency range 0.1 - 25 GHzStaged construction
Large bandwidths (4 GHz), large fields-of-view (50 deg2)New capabilities: area re-use (“multi-fielding”), RFI mitigation, high dynamic range imaging, ….
Innovative design to reduce costInternational funding: ~ € 1.5 billion17-country international consortium
– International SKA Project Office (ISPO) since 2003
2 short-listed sites; final selection ~ 2011– Western Australia, Southern Africa
Hugedata rates& volumes
}
ISPO
radio “fish-eye lens”
Inner core
Station
Digital radio camera + stations to3000 km
Radio fish-eye lens
SKA pictorially
ISPOSKA characteristics
Exploits convergence of radio and ICT– More parameter space, flexibility = more discovery
Uses less metal, more ICT– Many gains via consumer-driven technologies
Is an incubator for selected leading-edge technology– Astronomers are “sophisticated end users” – (Radio astronomy is traditionally an effective incubator)
Design paradigm poses new challenges– But gives new players opportunities to develop pivotal
technologies
7
ISPO
SKA conceptually- radio meets IT
(Antennas)
ISPOThe antenna dilemma
What defines the primary FoV?(1st stage beamformer technology)
Optics Electronics
Concentrator (dish) Aperture phased array
Analog (RF)beamform
Digitalbeamform
Technology choice depends on applications, frequency and delivery epoch
FOV expansion•Optical (multiple feed cluster)•Electronic (phased array feed)
continuum
ATA, KAT, APERTIF, ASKAP EMBRACE LOFAR 2-PADMWABEST, SKAMP
Extreme electronic beamforming
ISPO“Reference Design” antennas
> 3 GHz: wide-band feed
< 0.3 GHz: sparse aperture array
0.3 – 3 GHz:phased arrayfeed
Mid-band all-sky monitor: dense aperture array
Mid-BandHigh-Band
Swinburne/CVA visualization
Low-Band
ISPOSKA antenna applications
Frequency range(GHz)
Sparse Aperture Array
Dense Aperture Array
Dish + Focal Plane Array
Dish + Single-Pixel Feed
Low-band“EoR” array
0.1-0.3
All-sky monitor
0.3-1
Imaging mid-band array
0.3-3
(to ~0.5 GHz) (to ~1 GHz)
High-band array
3-25
Pathfinders or Design Studies
LOFAR, MWA, LWA
SKADS ASKAP, APERTIF
ATA, TDP, meerKAT
Mid-band SKA is the focus of intense Pathfinder activity
ISPOSKA development
Astronomy & engineering iteration to refine specifications– Specs agreed by early 2008
International system design effort ramping upEmphasis on technology demonstration– Retire risk as early as
possible– Regional pathfinders &
design studies are crucial» > €200M investment
Focus on:– Aggressive cost reduction
strategies– Industry engagement
» To deliver SKA on required timescales
Reference Designtechnologies
1% (Pathfinders) 10% (SKA Phase 1) 100% (SKA)
ISPO
SKA – not just antenna challengesHigh speed data transport– Tb/s from EACH station on scales of hundreds of km – 100 Gb/s trans-continental and trans-oceanic links
Signal processing– Peta-ops per second– Need highly scaleable solutions
Post-processing– Computing capacity limitations require staged science
capability– Archive and sharing of data will be a major challenge
Infrastructure– Civil, electrical (power, …), communications
Operations and support– Expect operations cost of €100 M annually
ISPO
2000
Sites short-listed ‘1% SKA’
Science
Sciencecase
published PrepSKA preparatory phase
activities ‘10% SKA’Science
98 2002 06 07 08 09 10 11 12 13 14 18 22
Feasibility studies and
concept demonstration
Full arrayconstruction100% SKA
SKAComplete
Phase 1construction10% SKA
SKA timeline
Reference Design selected
Pathfinder suite construction
External review of top-level design
Concept design PrepSKA system design
Initial specs for Phase 1 and full SKA
Detailed Phase 1 design &top-level SKA design
ISPO
SKA Preparatory Phase – PrepSKA(2008 – 2011)
WP1: PrepSKA managementWP2: SKA system design– Includes Initial Verification System – Establishes central design integration team (CDIT)
WP3: Continuing site selection processWP4: GovernanceWP5: Industry and procurement policyWP6: Funding modelWP7: Implementation strategy
Strong international collaboration
ISPOPrepSKA system design
Outline Benchmark Spec.Parameter Memos Benchmark Spec. Comments
45/69 EOR AA Mid-AA DishesLow Freq. GHz ≤
0.1
0.1
0.3 >1.0
Will have some overlapHigh Freq GHz ≥
25
0.3
1.0 25
AA cost goes > square law with top frequencyBandwidth GHz 25%
0.2
0.7 5
This may be unrealistic for the dishes
Polarisations 2 2
2 2
Default linearPol error (after cal):
FOV centre/edge dB -40/-30
-40/-30
-40 /-30 -40/-30 Important for dynamic range and astronomy.
FOV: 0.1-0.3 GHz deg2 200 200 This is really total beam size 0.3-1.0 GHz deg2 50 250 The FOV naturally scales as 250(1/f)2
1.0-3.0 GHz deg2 1-10
3(1.4/f)2
Defined by a 6.1m dish natural beam size. 3.0-25 GHz deg2 0.33(3/f)2
3(1.4/f)2
FOV filling 100%
100%
100% 100% The full field of view should be filled with beamsNo. of steerable FOVs 1-4
4
8 1
AA FOV count limited by comms.
Survey @ 0.7GHz 1.5 x 1019
1.75 x 1019 Assumes 10,000m2/K sensitivitySpeed: @ 1.5GHz 3 x 1017
8.4 x 1017
Assumed 700MHz B/W at this freq, 3 deg2 FOV deg2 m4 K-2 Hz-1 (FoV x (A/T)2 x BW)
System temp Tsys K 50K
>100K
50K ≤30K
Assumes dishes use at least 70K coolingSensitivity @45°
m2K-1
>0.3 GHz 5,000 5,000 The sky noise is v. high for low freq 0.3 –
1.0 GHz 20,000 5-10,000 Reduced sensitivity by trading with large FOV 1-10 GHz 20,000 10,000 Single pixel feed so can cool for low system temp >10 GHz 10,000 10,000
Dynamic range 106
106
106 106
Peak b’ness to rms noise level (not ADC range!) Probably need ~107!
Overall SKA Configuration
Station
Core (5Km dia), made up of close packed stations
Correlatorin or near Core
Comms
links
Not to scale!DesertDesert
Link to Correlator
High freq. Dishes withanalogue fibre link
EoR
AA antennas withanalogue link (may be close packed)
SKA SKA StationStation
Notes:1. Power dist. not shown2. All analogue links go to
‘station processing’
Illustration only
StationProcessing
Station ProcessingBunker
2nd
StageProcessor 1
0.3-1.0GHz Analog
links
2nd
StageProcessor 2
2nd
StageProcessor X
…..
Dish P1Dish P2
Dish Px
Tile P1Tile P2
Tile Py
EoR
P1EoR
P2
EoR
Pz
.Internal
Digital links
n x Optical fibres per 2nd
stage processor
To Correlator
Mid Freq. AA
GPS Phase Standard
.
.
.
.
..
11+GHz Analog
fibre links
300MHz Analog
links.
.
.
High Freq. dishes
EoRAA
... Control processors
To CentralControl system
10Gb Digital fibre links
PrepSKA
WG2 An IT contribution
Packaging solutions for LNA
Network Infrastructure and Data Transmission
Final SKA Implementation Plan
IT tasks : WG2 & WG7
•
SKA-
ICT machine
(data transport
and detection-
~100Gby/s; xPetaflops) ; channel
through
10-40Gb/s links
•
Task
2.6 –
To produce
a suite
of
advanced
prototype
receivers
(based on
SKA PF and SKADS), testing
state
of
the
art
semiconductors,
close
to industry
. •
Task
2.7 –
To produce
advanced
prototypes
of
optical
fiber
data
transport
with
high
bandwidth, highly
sinchronized
(picosec) from 20m-200km. Importance
of
high-performance
commercial
telecoms.
•
Important
Effort
: 44 Man/month
over
3yrs (~50%U.Cam, Oxford, MPG).
•
Important
and Strategic
: R&D in
ICT cornerstones
and Physics..•
Strategic technologies: maintain
in
Europe
centers
for
semiconductor
production
and data links R&D. PT closer
to foundries.•
Portugal has
techological
readiness!!
•
Need
for Phase
1 : mass
production.
•
Close
partnership
with
Risk
evaluators
needed
(ie
Science
Agencies) –
WG4, WG5, WG6
LNA Testing
•
Tinstrument=40K (excluding sky noise), goal 30K
•
BW
70MHz –
1.0 GHz (two systems)
•
Survey speed ~1/T2•
Sensitivity
~1/T
LNA testing•
A 9 million element system with a total system cost of 250M €
can spend:
–
1,5 €
per LNA per Kelvin improvement (Survey)–
Or 8,5 €
for 5 Kelvin improvement, again for Surveys
•
Given a bare die costs of:–
0,5 €
for Silicon technologies (only 500 12 inch
wafers)–
2 €
for GaAs technologies (2000 6 inch wafers)
•
Low cost technologies cannot compromise on noise!
•
GaAs PsHEMT / mHEMT
•
SiGe BJT•
with b0 =100: FMIN
~30K
•
CMOS•
In principle similar to GaAs
LNA Technology
Amplifier Noise Figure Trends @1.4 GHz Tamb=290K
0
10
20
30
40
50
60
70
2000 2002 2004 2006 2008 2010 2012
year
Noi
se T
empe
ratu
re
III/V: GaAs or InPSiGeCMOS
• 0.2um technology• OMMIC differential LNA
– 2109– ASTRON design
PsHEMT
1 -Development of a prototype phase transfer system over installed fibre links.
2 -Cost model analysis for all aspects of the data network including installation and equipment costs.
•
Plan to use our existing equipment, simply transmit the signal optically, rather over microwave links.
•
Observe if the fibre link is reciprocal over distances up to 120 km
•
Show the current system is no worse than the existing system
•
Show that the system is accurate to 1 ps over 1 minute and 10 ps over 10 minutes
Master L-Band Link
HP 8508A Vector Voltmeter
Aerial switchSlave L-band Link
499.9MHz over 3m of RG214
SMF28 Fibre Link (variable length)
1486.3 MHz signal
1486.3 MHz signal over 30m of RG214
Master Laser
Master Receiver
Slave Receiver
Slave Laser
-23dB
-40dB
Lab path
Link path
499.9 MHz over 30m of RG214
•
Aperture
Arrays
(a kind
of
friendly
Synthetic
Aperture Radar for RA).
•
Need
for Massive
station
-
evaluate
Astrophysics readiness
•
Evaluate
technology
with
adverse, close
to real SKA operational
conditions
(hot, dry, dusty, high
thermal
amplitudes)•
Need
for solar power
plant
–
Portugal has
most
iluminated
area
in
Europe.•
Consortium
being
built
–
IT is one
of
the
participants
•
SKA –
R&D for green
energies
<-
isolated
stations
in
the desert
need
autonomous, low
maintenance
power
plants. Energy
option
–
Frauenhofer
Inst. Lidership. EFACEC
contacts
•
Implementation
: ready
by
2012 ; 6Meuros budget
to be distributed
among
partners
SKA demonstrator in Iberia
SKA demonstrator in Iberia
Over
EMBRACE SKADS prototypes
The Unknown•
New discoveries always result from observations in new parameter space–
sensitivity
–
spatial resolution–
spectral resolution
–
polarisation–
time domain
–
observing speed (multibeaming)•
eg. CMB, pulsars, extra solar planets,…
SKA improves all of these
SKA is designed for the Key Projects but with an overriding design philosophy of flexibility to maximise
the likelihood of new discoveries