1. Dec 2010 AAVP Cambridge workshop AAVP AAVS1/2-low demonstrators Jan Geralt Bij de Vaate

2. Dec 2010 AAVP Cambridge workshop AAVP Tile Digitisation Element Digitisation RFI Shielded......... Power Distribution Element Digitisation... Cooling Element Digitisation...... Station Processing RFI shielded System clock Control & Monitoring Station Beams Power Grid Element Data C & M Clock To Correlator & Services 2x 500MHz Analogue + power FibreCopper 2-Pol Elements Front-end SKA 1 : AA-low station Each station: Diameter:180m # of elements:11,300 Element links:Copper

3. Dec 2010 AAVP Cambridge workshop AAVP Proposed specification From draft SKA phase 1 system description, June 2010

4. Dec 2010 AAVP Cambridge workshop AAVP After the 50MHz issue.. And LOFAR / MWA /.. AAVS-low needs to address –Broadband Aeff / Tsys (antenna, lna, beamforming) –Broadband receiver –Cost effective signal processing –Calibration –Monitoring & Control Some specs need new developments Some (just) need proper choices –Note: one array for 50-450MHz not possible

5. Dec 2010 AAVP Cambridge workshop AAVP AA-low antenna design Addressed by –UCAM –INAF / IEIIT-CNR –ICRAR –ASTRON (2011) ~10 full scale antenna prototypes build 2011 Action –Agree on test approach/range –Extend analyses for scan angle and frequency Razavi 2010 Wijnholds 2010

6. Dec 2010 AAVP Cambridge workshop AAVP AA-low station Addressed by –UCAM –UMAN –2011..ICRAR, ASTRON Many options Action –Form (small) focussed team –AAVP, SPDO domain spec and scientist, ‘AA’ astronomer A p 1.5 km 2 0.84 km 2 0.59 km 2 0.42 km 2 Freq T sys A e8 /T s A e16 /T s A e32 /T s A e64 /T s MHz Km 2 K -1 43 9400 160 90 65 45 60 4000 375 210 150 105 85* 1600 940* 525 370 265 120* 700 1070 1200* 840 600 170* 320 1170 1310 1840* 1315 240* 160 1310 1840 2625* 340 85 1735 2470 480 60 1750 Bregman 2010

7. Dec 2010 AAVP Cambridge workshop AAVP Deployment cost Freq bandwidth A eff /T sys Dynamic range Random elementsHighGoodOptimal Random tilesModerateGood Regular grid tilesLowOptimalGood(strong gratings) Some trade offs -LOFAR, MWA, AAVP will need to confirm/complete the trade-offs -More: Filling factor, uv coverage, calibration, FoV etc..

8. Dec 2010 AAVP Cambridge workshop AAVP AA-low LNA Addressed by –INAF –ICRAR –UMAN Should not be an issue but –Coupling –Impedance, 50, 150, 300 Ohm –Differential LOFAR simulation, Kant

9. Dec 2010 AAVP Cambridge workshop AAVP AA-low receiver 6, 8 or 12 bits needed –8 fine? SPDO: please release new RFI data! RFI at 55MHz (not in this plot) –Levels?? –50-70MHz does not come for free Action –Requirements analyses: ASTRON+SPDO CoDR docs

10. Dec 2010 AAVP Cambridge workshop AAVP AA-low costing Analogies costing –LOFAR –MWA AA station model input by AAVP PE and AA domain specialist

11. Dec 2010 AAVP Cambridge workshop AAVP AAVS rationale Prototyping essential LOFAR initial test station and CS1, MWA 32T –Antenna array needs adequate receivers and back-end –Test software Common test platform needed! –For AA-low options & AA-mid –Site: Sufficient low RFI, fibre link, power, –Signal processing (limited bandwidth?) Action –Define requirements test platform

12. Dec 2010 AAVP Cambridge workshop AAVP AAVS1: AA-low Demonstrate electromagnetic and front end performance –Sufficient collecting area (250-500m 2 ?), possibly two versions –Focus on broadband antenna and front-end design –Evaluation using existing processing UNIBOARD, ROACH or LOFAR / MWA –Goal: establish antenna, tile and station configuration Extensive station simulations required –Critical Design Review 31-12-2011 –Commissioning 31-12-2012 –Reporting30-6-2013

13. Dec 2010 AAVP Cambridge workshop AAVP AAVS1: AA-low Actions –Specify AAVS1 –Based on SKA 1 System Requirement Specification –Hardware costs / resources AA-lo70 – 450 MHzOverlap with AA-hi to provide even sensitivity Inst. Bandwidth380MHzCombine both polarisations onto one processing channel System Temp120KAt 300 MHz, Sky noise 50K, T rec 70K Array TypeSparseIncreases A eff at low frequency to part counter Sky noise Scan angle±45° Polarisations2 linear Tile size64Dual polarisation elements No. of Tiles4 AAVP DoW March 2010, to be updated

14. Dec 2010 AAVP Cambridge workshop AAVP AAVS2: AA-low Pre production phase: –Preparing for mass-production, design for manufacturing AAVS2 prototype –Test tooled production components –SKA 1 performance compliance –Bandwidth, T sys, stability, signal processing, calibratability, climate –Critical Design Review 30-9-2013 –Construction2014 –Comisioning2015 –Reporting for SKA1 PR31-12-2015

15. Dec 2010 AAVP Cambridge workshop AAVP AAVS2 requirements In order to ramp-up production in 2016, AAVS2 should be sufficiently large: e.g. 1-2% SKA 1 (~10.000 elements) Built with SKA 1 tooling A couple of ‘d’ diameter stations including digital station beamforming –Note: e.g. if used UNIBOARD 2 needs to production ready by 2014 On the SKA site Acceptance tests of this station should be considered in absence of correlator Schedule is tight: custom MMICs, photonic links, signal processing boards

16. Dec 2010 AAVP Cambridge workshop AAVP AA-low Montly telecons Wiki for progress docs, minutes etc. –www.ska-aavp.eu/aavpwiki Workpackages –System design –Antenna element, array –Front-end (LNA, receiver, data link) –Calibration & beamforming –Proto type, Design, Construction & commisioning, Evaluation