The Square Kilometre Array: Overview and Engineering Update

The Square Kilometre Array is currently undergoing the Preliminary Design Reviews for its composing elements, and is thus at a critical point on its way to becoming ready for construction starting in 2018. In this talk we will provide an overview of the SKA, its composing elements, and their status, with emphasis on the Telescope Manager and the Science Data Processor, respectively the Monitoring & Control system, and Pipeline. We will see how do they compare with their ALMA equivalents, and how is the SKA similar/different from ALMA.

Seminar given on Dec 11, 2014, at the ALMA Headquarters in Vitacura, Chile.

Transcript

1. The Square Kilometre Array:
   Overview and Engineering Update
   ALMA SCO HQ, Dec 11 2014
   Juande Santander-Vela
   

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2. • Who am I?
   
   • SKA Science
   
   • Site, Telescopes, Technologies
   
   • SKA Organisation
   
   • Engineering Progress
   
   • SKA: the Exaflop HI Tomograph
   
   • ALMA vs. SKA: Telescope Control
   
   • What’s Next?
   Outline
   ALMA SCO HQ, Dec 11 2014
   

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3. Who am I?
   ALMA SCO HQ, Dec 11 2014
   

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4. • Systems Engineer for the SDP/TM elements
   (since March 2014)
   
   • VIA-SKA Project Manager (Jan ’12-Feb ’14)
   
   • Former VLT Archive Applied Scientist (Jun ’09-
   Feb ’11), ALMA Science Archive Front-/Back-
   end Developer at ESO Garching (Mar-Dec 2011)
   
   • Ph.D. in Radio Astronomical data archives &
   Virtual Observatory
   
   • Software Analyst/Manager in Industry
   Who am I?
   ALMA SCO HQ, Dec 11 2014
   

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5. • Introduction
   
   • Science
   
   • Site, Telescopes, Technologies
   
   • SKA as an Exaflop Camera
   
   • Engineering Progress
   
   • What’s Next?
   Great observatories of the present…
   ALMA SCO HQ, Dec 11 2014
   

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6. • Introduction
   
   • Science
   
   • Site, Telescopes, Technologies
   
   • SKA as an Exaflop Camera
   
   • Engineering Progress
   
   • What’s Next?
   …and the future
   ALMA SCO HQ, Dec 11 2014
   

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7. • Introduction
   
   • Science
   
   • Site, Telescopes, Technologies
   
   • SKA as an Exaflop Camera
   
   • Engineering Progress
   
   • What’s Next?
   …and the future
   ALMA SCO HQ, Dec 11 2014
   

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8. • Introduction
   
   • Science
   
   • Site, Telescopes, Technologies
   
   • SKA as an Exaflop Camera
   
   • Engineering Progress
   
   • What’s Next?
   …and the future
   ALMA SCO HQ, Dec 11 2014
   

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9. SKA Science
   ALMA SCO HQ, Dec 11 2014
   

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10. Fundamental Forces &
    Particles
    • Gravity
    
    • Radio pulsar tests of
    General Relativity
    
    • Gravitational Waves
    
    • Dark Energy
    
    • Magnetism
    
    • Origin and evolution of
    Cosmic Magnetism

    Origins
    • Galaxies and the Universe
    
    • Cosmic Dawn
    
    • First Galaxies
    
    • Galaxy Assembly &
    Evolution
    
    • Stars, Planets & Life
    
    • Protoplanetary Disks
    
    • Biomolecules
    
    • SETI
    Why we do this? SKA Science Goals
    ALMA SCO HQ, Dec 11 2014
    XX Century: We discovered our place in the Universe
    XXI Century: We understand the Universe we inhabit
    Some of these can
    only be achieved
    with SKA2
    

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11. • Initial SKA Science Book (2004): 5 KSPs,
    43 additional ones
    
    • Updated SKA Science Book (2014):
    13 Phase 1 Headline Projects, 130 Chapters
    
    • Projects reduced, parameterised from ~43
    projects, through science prioritisation
    exercise with SKAO and SWGs
    SKA Science Goals
    ALMA SCO HQ, Dec 11 2014
    

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12. • Astrobiology (“The Cradle of Life”)
    • Project Scientist: Tyler Bourke
    
    • WG Chair: Melvin Hoare
    
    • Galaxy Evolution – Continuum
    • Project Scientist: Jeff Wagg
    
    • WG Chairs: Nick Seymour &
    Isabella Prandoni
    
    • Cosmic Magnetism
    • Project Scientist: Jimi Green
    
    • WG Chairs: Melanie Johnston-
    Hollitt & Federica Govoni
    
    • Cosmology
    • Project Scientist: Jeff Wagg
    
    • WG Chair: Roy Maartens
    
    • Epoch of Reionisation & Cosmic Dawn
    • Project Scientist: Jeff Wagg
    
    • WG Chair: Leon Koopmans
    
    • Galaxy Evolution – HI
    • Project Scientist: Jimi Green
    
    • WG Chairs: Lister Staveley-Smith
    & Tom Osterloo
    
    • Pulsars (“Strong field tests of gravity”)
    • Project Scientist: Jimi Green
    
    • WG Chairs: Ben Stappers &
    Michael Kramer
    
    • Transients
    • Project Scientist: Tyler Bourke
    
    • WG Chairs: Rob Fender & J.-P.
    MacQuart
    SKA Science Goals: WGs
    ALMA SCO HQ, Dec 11 2014
    

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13. SKA Science Goals: Headline Projects
    ALMA SCO HQ, Dec 11 2014
    Year in the life of SKA1: Mock-up
    3-years scheduling to constrain
    operations, computation
    

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14. Telescopes, Sites,
    Technologies
    ALMA SCO HQ, Dec 11 2014
    

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15. SKA Telescopes
    ALMA SCO HQ, Dec 11 2014
    SKA1-Low
    

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16. SKA Telescopes
    ALMA SCO HQ, Dec 11 2014
    SKA1-Mid
    

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17. SKA Telescopes
    ALMA SCO HQ, Dec 11 2014
    SKA1-Survey
    

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18. ALMA SCO HQ, Dec 11 2014
    SKA1-Mid:
    Karoo Site
    

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19. ALMA SCO HQ, Dec 11 2014
    SKA1-Low/-Survey: Murchison Radio Observatory
    

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20. SKA Organisation
    ALMA SCO HQ, Dec 11 2014
    

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21. • Australia (DoI)
    
    • Canada (NRCZHIA)
    
    • China (MOST)
    
    • Germany (BMBF)
    
    • India (NCRA)
    
    • Italy (INAF)
    
    • Netherlands (NWO)
    
    • New Zealand (MED)
    
    • South Africa (DST)
    
    • Sweden (Chalmers)
    
    • UK (STFC)
    SKA Organisation
    ALMA SCO HQ, Dec 11 2014
    Currently UK Company Limited by Guarantee → Treaty Organisation
    Other partners in negotiation, expected
    

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22. SKA Governance: Pre-Construction
    ALMA SCO HQ, Dec 11 2014
    *
    *
    *
    *
    *
    *
    *
    *
    *
    *
    *
    *
    *
    *
    *
    *
    *
    *
    SKA Governance
    Members$
    Board$of$Directors$
    $
    SKA$Office$
    ~50$staff$
    $
    Director;General$
    11$Design$ConsorXa$
    ~500$ScienXsts$&$Engineers$
    Strategy$&$$
    Business$Dev$
    Cmte$
    Finance$
    Cmte$
    ExecuXve$Cmte$
    Science$&$Eng$
    Advisory$Cmte$
    €23.4M$
    (cash)$
    ~$€125M$
    (in;kind)$
    

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23. SKA International Design Consortia
    ALMA SCO HQ, Dec 11 2014
    Project Management and System Engineering Team based at JBO (UK)
    ~500 scientists & engineers in institutes & industry in 11 Member countries
    

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24. Engineering
    Progress
    ALMA SCO HQ, Dec 11 2014
    

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25. 64 x 13.5m offset Gregorian
    antennas
    
    8km maximum baseline length
    
    First receivers:
    
    0.9 – 1.67 GHz (L-band)
    
    0.58 – 1 GHz (UHF)
    
    770 MHz bandwidth
    
    Early operations 2016/7
    SKA1 Precursors: MeerKAT
    ALMA SCO HQ, Dec 11 2014
    First light with L-band
    receiver and digitiser
    erKAT
    

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26. SKA1 Precursors: MeerKAT
    ALMA SCO HQ, Dec 11 2014
    Lot’s more of infrastructure already in place: dish assembly shed; bunkered and RFI
    shielded data processor room and power system
    

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27. SKA1 Precursors: MeerKAT
    ALMA SCO HQ, Dec 11 2014
    Lot’s more of infrastructure already in place: dish assembly shed; bunkered and RFI
    shielded data processor room and power system
    

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28. SKA1 Precursors: ASKAP
    ALMA SCO HQ, Dec 11 2014
    36 x 12m antennas
    3-axis movement
    30m – 6km baselines
    Novel PAF receiver
    700MHz – 1800MHz
    Wide field of view
    Fast survey speed
    

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29. BETA
    
    • 6 Mk I PAFs and digital systems
    
    • Commissioning, learning about beamforming 

    Lesson: deploy early, test, ensure adequate
    gap to production commitment
    
    ASKAP
    
    • First Mk II PAF installed
    
    • Results expected in next few weeks
    
    • Production of Mk II PAFs install through to Feb 2016
    SKA1 Precursors: ASKAP
    ALMA SCO HQ, Dec 11 2014
    

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30. SKA1 Precursors: MWA
    ALMA SCO HQ, Dec 11 2014
    Murchison Widefield Array, Operational
    17 refereed papers published, more coming
    

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31. 3 dish prototypes in testing
    ALMA SCO HQ, Dec 11 2014
    

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32. SKA: the Exaflop
    HI Tomograph
    ALMA SCO HQ, Dec 11 2014
    

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33. • Dishes, feeds, receivers (N=250 → 2500)
    
    • Low and mid aperture arrays (n=250k → 1000k)
    
    • Signal transport (~1 Pb/s → 10 Pb/s)
    
    • Signal processing (exa-MACs)
    
    • Software engineering & algorithm development
    
    • High performance computing (exa-flop
    capability)
    
    • Data storage (exa-byte capacity)
    
    • (Distributed) power requirements (10 → 50MW)
    Engineering Challenges
    ALMA SCO HQ, Dec 11 2014
    

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34. SKA High-Level Architecture
    ALMA SCO HQ, Dec 11 2014
    SKA-TEL-SKO-DD-001
    Revision : 1
    Figure 1 A schematic diagram of the SKA Observatory, showing the geographical locations of site entities
    (telescopes), the entities at regional centres (Host Country Headquarters and Science Data Processing), and
    Regional
    Science &
    Engineering
    Centre(s)
    Regional
    Science &
    Engineering
    Centre(s)
    SKA Observatory Global
    Headquarters
    Remote stations
    on spiral arms
    Science
    Computing
    Remote
    Station
    Remote
    Station
    Remote
    Station
    Host Country
    Headquarters
    Central Signal
    Processing
    SKA1-low
    SKA1-survey
    Core Arrays
    Australia
    Remote stations
    on spiral arms
    Science
    Computing
    Remote
    Station
    Remote
    Station
    Remote
    Station
    Host Country
    Headquarters
    Central Signal
    Processing
    Mid-Freq
    Aperture Array
    (SKA2)
    SKA1-mid
    Core Arrays
    South Africa
    

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35. SKA Elements & Interfaces
    ALMA SCO HQ, Dec 11 2014
    INFRA
    DSH
    LFAA
    CSP SDP
    TM
    Command control flow
    Data flow
    SaDT
    Timing
    Conceptual figure:
    it should be split by
    telescope
    

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36. SKA Elements & Interfaces
    ALMA SCO HQ, Dec 11 2014
    INFRA
    DSH/LFAA CSP SDP TM
    Command control flow
    Data flow
    SaDT
    Timing
    Conceptual figure:
    it should be split by
    telescope
    

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37. • Software Defined Networking
    
    • Allows easy partitioning, sub-arraying,
    quality of service, commensality…
    
    • Software Defined Beamforming (-Low, -
    Survey)
    
    • Software Defined Computing
    
    • Data-Flow Driven Science Data
    Processing
    SKA is a Software-Defined Telescope
    ALMA SCO HQ, Dec 11 2014
    Lots of computing challenges
    

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38. ALMA SCO HQ, Dec 11 2014
    Science Data Processor Local M&C
    Science Data Processor
    Telescope Manager
    Correlator /
    Beamformer
    Data Routing Ingest
    Visibility
    processing
    Multiple
    Reads
    Time Series
    Search
    Multiple
    Reads
    Data$Buffer
    Data Routing
    Time Series
    Processing
    Image Plane
    Processing
    Data
    Prodcuts
    Sky Models,
    Calibration
    Parameters ...
    Meta Data
    Master Controller
    Master Controller
    Local M&C
    Database
    Tiered Data
    Delivery
    

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39. ALMA SCO HQ, Dec 11 2014
    Performance Modelling
    •  Imaging and calibration determines
    system sizing
    •  Data is Buffered after Ingest
    •  Detailed analysis building on Cornwell:
    •  Imaging
    o  AW-projection
    o  Plus w-snapshots
    o  Plus faceting (working memory size)
    •  Continuum imaging always required for
    calibration
    o  Field of view to second zero of beam
    •  Maximal case includes “science discovery”
    mode of forming high spectral-resolution image
    cube over primary beam
    •  Commensal fast-imaging mode for slow
    transients
    Processing
    maximal
    (Pflop)
    Ingest
    (GB/s)
    Use Case
    examples
    (GB/s)
    LFAA! 100! 7300! 245!
    Survey! 135! 4600! 995!
    Mid! 360! 3300! 255!
    Detailed analysis is much
    more complicated
    courtesy
    

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40. SKA1 Archive Size
    ALMA SCO HQ, Dec 11 2014
    

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41. ALMA vs. SKA:
    Telescope Control
    ALMA SCO HQ, Dec 11 2014
    

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42. • Need to find COTS-based solution
    
    • Move away from expensive hard real-time
    solutions
    
    • Switched network inside products
    
    • Orchestration instead of deterministic control
    
    • Certain amount of product independence
    SKA Control Problem
    ALMA SCO HQ, Dec 11 2014
    

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43. SKA Elements & Interfaces
    ALMA SCO HQ, Dec 11 2014
    INFRA
    DSH
    LFAA
    CSP SDP
    TM
    Command control flow
    Data flow
    SaDT
    Timing
    Conceptual figure:
    it should be split by
    telescope
    

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44. ALMA SCO HQ, Dec 11 2014
    Figure 1. ALMA Software Subsystems interaction diagram (source: ALMA Software documentation)
    CSP
    SDP
    SDP.PIP.*
    SDP.PIP.*
    TM.OBSMGT
    TM.TELMGT
    SDP.INGEST
    

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45. ALMA SCO HQ, Dec 11 2014
    TM.TELMGT
    TM.OBSMGT
    DSH.LMC CSP.LMC
    SDP.INGEST SDP.PIP.* SDP.ARCH
    SDP.LMC
    Commands
    Data
    Monitoring/Status
    CSP.CORR
    DSH.RECEIVER
    SKA Observation interaction: SKA1-Mid
    

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46. ALMA SCO HQ, Dec 11 2014
    Ethernet switching
    Middleware TBD
    (EPICS/TANGO/OPC UA)
    DSH.LMC
    SADT.DDBH
    SADT.TM
    CSP.LMC
    SADT.SAT
    

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47. ALMA SCO HQ, Dec 11 2014
    TM.TELMGT
    TM.OBSMGT
    TM.TELMOD
    SDP.PIP.
    

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48. What’s next?
    ALMA SCO HQ, Dec 11 2014
    

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49. 2016
    2015 2017 2018 2019 2020 2021 2022 2023
    2014
    High/level/design
    Rebaselining/submissions/(RBS)
    Preliminary/Design/Review/(elements)
    Detailed/design
    Prototype/systems/deployed
    Critical/Design/Review
    SKA1/construction/approved
    Procurement
    SKA1/early/science
    SKA1/construction
    SKA2/detailed/design
    Design/consortia/start
    SKA2/procurement
    SKA2/construction/starts
    SKA2/concept/development
    Board/RBS/approval 3K5/Mar/15
    15K22/Sep/14
    1/Nov/13
    PreKconstruction/Stage/1
    PreKconstruction/Stage/2
    Production*Readiness*Review*(4*dish*array)
    Construction*Readiness*Review*
    (1*dish*line9up)
    New/SKA/Organisation/in/place
    Key/Doc/Set/&/Prospectus
    Formal/negotiations
    Ratification/of/Agreements Organisation/has/minimum/no./Members/with/Agreements/ratified
    Agreements/in/Key/Doc/Set/signed
    Andrea/Casson,/SKAO/Project/Controller,/Sept/2014
    System/PDR
    Integration/testing/on/site
    Advanced/Instrumentation/Prog.
    KEY:/Blue/=/SKA1/science/&/engineering;/orange/=/policy;/green/=/SKA2;/milestones*in*italics*=/proposals/under/discussion
    The SKA1 timeline
    

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50. The SKA1 timeline
    ALMA SCO HQ, Dec 11 2014
    Issue%Baseline%
    Design
    Science%
    Assessment%
    Workshops
    Proposal%
    Feedback
    Level%1%
    Requirements%
    Feedback
    Science%
    Conference
    Engineering%
    Meeting
    Engineering%Change%Proposals
    Designs%&%
    Costs
    SKAO%Review
    Technical%
    Advice
    (working%
    groups)
    SEAC
    Board
    Consortium%Design%Activities
    Level%0%
    Requirements
    Brief%
    SEAC
    2013 2015
    Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar
    2014
    PDR
    Science
    Review%Panel
    Science
    Review%
    Panel
    !! !!
    !! !!
    !!
    !!
    !!(43)
    !!
    !!
    !!
    !!
    Issue%Baseline%
    Design
    Science%
    Assessment%
    Workshops
    Proposal%
    Feedback
    Level%1%
    Requirements%
    Feedback
    Science%
    Conference
    Engineering%
    Meeting
    Engineering%Change%Proposals
    Designs%&%
    Costs
    SKAO%Review
    Technical%
    Advice
    (working%
    groups)
    SEAC
    Board
    Consortium%Design%Activities
    Level%0%
    Requirements
    Brief%
    SEAC
    2013 2015
    Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar
    2014
    PDR
    Science
    Review%Panel
    Science
    Review%
    Panel
    

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51. Questions?
    Juande Santander-Vela
    j.santander-vela@skatelescope.org
    

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