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Arnold van ArdenneAAVP overviewAAVP_AvA08122010Courtesy: Lofar & SKADS/AAVP teams
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Effelsberg (D)
Tautenburg (D)
LOFAR Stations Across Europe
Potsdam (D)
Unterweilenbach (D)
Exloo (NL)
Chilbolton (UK)
Nançay (F)
Onsala (Sw)
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
~ 300 Dishes
~ 50 Sparse Aperture Array
Stations
70 – 450 MHz
Central
Region
Single pixel feed
450 MHz – 3GHz
Baseline design for SKA1;
Array & Receptor Technologies
Artist renditions from Swinburne Astronomy Productions,
courtesy: SPDO
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
and in parallel
The Advanced Instrumentation Program
Further development of innovative wide-field “radio camera”
technologies with the potential to enhance Phase 1 and be a major
part of Phase 2:
• dense aperture array
• phased array feeds (PAFs) on the dishes
Decision in 2016
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
~ 250 Dense Aperture Array
Stations 300-1400MHz ~ 2700 Dishes
~250 Sparse Aperture Array
Stations 70-450MHz
3-Core
Central
Region
Advanced Instrumentation
Program SKA2
Artist renditions from Swinburne Astronomy Productions,
courtesy: SPDO
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Planning for this decade
detailed design
& pre-
construction
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
prototyping and
costing 1st gen.
instrumentation
construction,
commissioning (AIV)
& shared-risk obs.
technology development ,
prototyping and costing
2nd generation instrumentation
detailed design &
pre-construction
2nd gen. instr.
construction,
commissioning (AIV)
& shared-risk obs.
Selection of 2nd generation instrumentation
System Design ,Infrastructure,
Costing, Detailed Design,Pre-Constr.SKA1 science operations
Enddate MOA
Enddate PrepSKA WP2
AAVP
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Principal Deliverables in time
AA-lo technology demonstrator & costed sub-system design 2013
SKA1 full pre-production prototype array 2015
SKA1 manufacturing data package 2015
AA-mid single array performance demonstrator 2013
multi-array interferometer performance demonstrator 2015
SKA1 capable costed design 2015
AA system AA-lo and AA-mid CoDR 2010
SKA2 technology roadmap & costed system design 2015
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
SKA Widefield System scenario
System concept
Sparse Aperture array
(AA-lo)
250 stations , 180m
Dense Aperture array
(AA-mid)
250 stations , 56m
Dishes with single pixel
feed
1200 dishes, 15m
Freq. Range 70 MHz to 450 MHz 400 MHz to 1.4 GHz 1.2 GHz to 10 GHz
―Flexible SKA concept with huge science potential ―
Scenario Being studied:
Courtesy: Jason Hessels
& LOFAR Pulsar Working Group
Widely seperated multibeams
key feature in LOFAR and AA’s
In general:
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Mapping SKA science cases;
Widefield System scenario
See e.g.SKADS White Paper,
SKA memo 122
Courtesy: Andy Faulkner, Paul Alexander
Area of
Major AA
benefit
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Phased arrays; key questions
• Can we afford them within SKA framework
– As investment
– As operating instruments (computationally, reliability, upgradability…)
• Will they perform
– Scientifically (Widefield scanned deep polarimetric Imaging)
– Technically (Noise, beamstability, reliability, ..)
• Will they be there in time
– For SKA Phase1 construction
• What wil be the optimal frequency range
– Related to all the above
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
AA-relevant background
• Some SKADS Results (publicly available):
• White paper with SKA widefield scenario as key
• Conference book with results and EMBRACE movie (DVD available)
• SKA(DS) memos & publications (www.skads-eu.org)
• Full cycle of Simulations
• Simulated skies (S-cubed) to Astrodata/pipeline,
using MeqTrees, released version MeqTrees, Beamsimulations
• E.M. & Circuit modelling
• Costing tool
• Demonstrators like Embrace/2_PAD/BEST
• Delivered First go on data processing and computing vs. required power
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
AA-mid pointer: EMBRACE;a first 0.5-1.5GHz Dense SKA-AA Demonstrator
Nancay
?
Courtesy: ASTRON, OPAR, INAF, MPIfR
FOV: ~ 140 sq. deg. / tile beam @ 1200 MHz
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Modelling large antenna arrays
• A multi-scale antenna problem — arrays of subarrays
– Total Solve Time: ~10 min.
(Single CPU 1.73 GHz, 2.0 GB RAM) ~35x faster!
• Combining antenna EM-models with MW-circuit models
• An antenna system simulator
Prototype Array HFSSHFSS
M. V. Ivashina, E. A. Redkina and R. Maaskant, “An Accurate Model of a Wide-Band Microstrip Feed for Slot Antenna Arrays”, IEEE AP-S International Symposium, Honolulu, Hawaii, June 2007.
CBFM + Feed Model
+=
M. V. Ivashina, E. A. Redkina and R. Maaskant, “An Accurate Model of a Wide-Band Microstrip Feed for Slot Antenna Arrays”, IEEE AP-S International Symposium, Honolulu, Hawaii, June 2007.
CBFM + Feed Model
+=
syseff TA /
MW Simulator
+
+
syseff TA /
MW Simulator
+
+
EM Simulator
)(skyT ,iE
EM Simulator
)(skyT ,iE
Using BG:
Courtesy: Rob Maaskant et. al.
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Understanding the Noise budget
Expected Aperture Array noise performance
Spill-over 0 K
Vivaldi feed loss 9 K
Low Noise Amplifier ~16 K
Noise mismatch / coupling /2nd stage 7 K
Sky 8 K
Total 40 K
Note:
depends on
scanangle
Measured Active reflection coefficient while scanning:
(noise coupling changes as scan angle changes)
Courtesy: Bert Woestenburg , Dion Kant et. al.
APERTIF in Aperture Array mode showing Tsys<55K
Courtesy: Bert Woestenburg, Laurens Bakker
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
AA-lo array
• Limited specification available but memo125 reads:
– 70 – 450MHz
– 2000 m2 / K (z=10)
• Interesting pointer WP2 talks e.g. Leon Koopmans (f-lo
50MHz?)
• Single/Dual AA-Lo?
• This Workshop to iterate on specs
AA-low
Low frequency 70 MHz, 50MHz, lower?
High Frequency 450 MHz
AA Type Sparse, Density at lowest
frequency?
Element Single or Dual
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
SKA Phase 1EMBRACE
2 - PAD
Technology Dev.
StudiesSKA
PositioningProject size:
~18-20M€
100+ FTE
42 month
15 institutes
9 European countries
+ Australia & SA
www.SKA-AAVP.eu
www.ska-aavp.eu/aavpwiki
Sparse Aperture Arrays
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Background; AAVP working methods
• WP2.3 of the International SKA PrepSKA WP2
SKA Phase 1 - SKA1 – has AA-lo as a main part
AAVS as part of AAVP is building the AA demonstrators
AAVP Kick off held in March
• AA-System and Technology packages (AA-SDS & AA-Tech) are
―output‖ packages aligned with overall SKA planning
• The verification activity AAVS comprises both AAVS1=AA-low
toward Phase1/SKA-lo and AAVS2=AA-mid toward AIP/SKA-mid
• The Emulation package emulates a test and reference site
(temperature range/cycle, RFI, easy logistics)
• Output through small (~5-10 persons)Task Groups
• Connections to SPDO at all levels, see Structure diagram
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
ESKAC-Exec +key SH’s+Observers
=AAVP Steering group
SPDO
AA-midASTRON/UK
AA-hi build and test
1. EMBRACE/2PAD eval.
2. AAVS-hi design
3. Industral’n & M/f
4. Site preparation
5. Integrate
6. Calibrate & comm’n
7. Central proc dev.
X. Sub-system dev
AA-lo 1ICRAR
AA-lo single element build and test
1. AAVS-lo design
2. Industral’n & M/f
3. Integrate
4. Calibrate & comm’n
5. Performance eval’n
X. Sub-system dev
AA-TechASTRON
Technology development
1. AA-hi array design
2. Tsys Optimisation
3. RF chain
4. ADC & Tile proc’ing
5. Station processing
6. Station calibration
7. Infrastructure
8. AA-lo array design
AA-SDSUK
AA System design studies
1. SSKA level simulations
2. tation level sims.
3. Specify & model AAs
4. Imaging & calibration
5. Cost/Power modelling
6. AA-lo data collection
7. Assess & final reports
AA-lo 2INAF
AA-lo dual element build and test
1. AAVS-lo design
2. Industral’n & M/f
3. Integrate
4. Calibrate & comm’n
5. Performance eval’n
X. Sub-system dev
WP1 WP2 WP3 WP4 WP5
Ver. 2.0
AAVP
Organisation
Aperture Array Verification System
AAVP TeamCoordinator Engineer
System Engineer Scientist
AA-SEMPRAC
Develop European Site
1. Site eval’n, selection & requirements
2. Infrastructure dev.
3. Install, commission & test AAs
4. Green energy development
.
WP6
ESKAC
SSEC
PM
AA-loAA-mid
PS/PE
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
AAVP Short term Activity Schedule
Fully absorb ASTRO2010, PEP toward SKA-1 elements
Fiancially
Technical
Increased focus on AA-lo
Arrive at Update Work Schedule
Update AAVP Activity Document
Funding awaited UK, It, progress not hampered
HW/SW (―stuff‖) funding probably ok till 2012
Optimize for AA global & absorb results from this
Workshop.
Arrive at updated specs (preliminary now)
Prepare for CoDR April 2011
AAVS now preparing SRS & ADD
Discussing updates
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Who are presently involved?
Consortium/Institute Country
UK-PrepSKA UK
ASTRON/Kapteyn Inst._RUG/Leiden
Obs._Univ.Leiden Nl
MPIfR Germ.
Obs. De Paris/Obs. Bord./Ud'Orléans Fr
INAF_IRA It
OAN Sp
OSO_ChTU Sw
Torun Centre of Astronomy_UMK Pol
JIVE Europe
PRAC Port
ICRAR Aus
NRF S.A.
SPDO/PrepSKA-WP2
Note: US representative ―only‖ through SPDO
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
High level questions with (dense)
Aperture Arrays
• Can we make Tsys ―low enough‖? – Probably: uncooled <15K already achieved (JGbdV et.al.)
• Science Verification; Calibration and imaging to the ―required‖ dynamic range in dual pol.?– Cailbration: Reconstructable polarimetric beamshapes (other presentation)Note1: AA have no obstacles and low sidelobes (TBC)
Note 2: Calibration: Intra-, Inter tiles redundancy intrinscially possible, design for
interstation redundancy (other presentation)
• Computational power less problematic for AA’s – See SKADS white paper, SKA memo 108 etc.
• Focus on mass production (methods)
• Cost reduction to an ―affordable‖ level?– Recent: SKA memos 93 & 111
– Preliminary conclusion: Viable SKA with AA & Dishes possible
• Overall power consumption (AAVP); ―greening the SKA‖ (note: PITF)
• Availability/Maintainability/Upgradibility
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Potential for Calibration AA’s
• Regular arrangement in phased array stations like LOFAR HBA and
EMBRACE, provides plenty of redundant baselines
• This can be used for inner-tile/inner-station calibration
• Can use: LOFAR HBA’s go from dense to sparse regime > 120MHz
• Now: potential use (e.g. also for diagnoses) and limitations now
being investigated (Parisa Noorishad, Stefan Wijnholts)
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
SKA-AAVP and Sustainable Society• Position SKA as First Sustainable Energy Mega-science Project
– Society wants it (!,?)
– Example: Zero Carbon Australia Stationary Energy Plan (100% carbon-free in
10yrs)
– European Platform of Universities in Energy Research (EPUE)
• AAVP Activities could/should also focus on
– Sustainable Power supply
– Power use e.g. Self-sustainable AAVP receptors/tiles, low-power processing
– Materials e.g. environmentally friendly
• Key industrial involvement; in Europe:
– Mediterranian Europe in particular Spain, Portugal
– Research supported by EC/ part of ESFRI roadmap (6 projects)
– Other countries e.g. Germany, Siting Countries?, other…
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Power: Computations per Kilowatt-hr
Faster
then
Moore!
Blue
Gene/Q
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
AAVP needs Test Site;
AA-SEM: Site emulation in Portugal• Low RFI
• Low/Excellent RFI conditions & (potential) Radio protected zone
selected in Moura (Contenda Forest)
• Compatibility/comparison with final site shaping to be done
•Tentative conclusion (report available):
• ―>20dB better ― <1GHz
• (much)better >1GHz when compared to WSRT
• Network technology demonstrator site
• Exploring energy related issues wrt SKA durable
energies
• Recent Analysis (AF)
– Total AA station power: Phase 1: 175 kW
Phase 2: 100 kW
• Demonstrator site sustainable energies
• Site development started to be ready March 2011
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
AA-SEM; Site emulation
Surface Solar Data (MJ/sqrm-day)
0,00
5,00
10,00
15,00
20,00
25,00
30,00
35,00
Jan
Mar
chM
ayJu
ly
Septe
mbe
r
Nov
embe
r
Netherlands
(Maastricht)
Portugal (Evora)
Australia
(Canberra)
South
Africa(Capetown)
Conclusion: Solar Energy levels Evora roughly comparable
with the larger potential SKA site areasSource:Solar Energy Pocket reference (Int.Solar Energy Soc.) 2005, ISBN 0-997128
Hot days Tmax>30; dark red –120-150 days; red – 90-120 days
Arnold van ArdenneAAVP overviewAAVP_AvA08122010
Summary
• Aperture Arrays shown to work
– LOFAR, EMBRACE
– So far no major blocking encountered
• SKA-AAVP next step to Phase 1 required
– conclude AA R&D phase and technical, science and cost performance
– Arrive at level for informed Phase 1 construction decision
– Same wrt. Phase 2
• Right Time:
– LOFAR/MWA etc. provides important input e.g. wrt.
• Calibration , low frequency science, low cost, processing etc.
– SKADS finished: produced
• Technology ML’s, costing tool, simulations and demonstrators