1 / 26

The Murchison Widefield Array: an SKA Precursor

The Murchison Widefield Array: an SKA Precursor. Shep Doeleman - MIT Haystack For the MWA Project. A wide-field, low-frequency imaging array Optimized for wide FOV, high survey speed Frequency range 80-300 MHz: Sample RF Three key science goals Epoch of Reionization

cheng
Télécharger la présentation

The Murchison Widefield Array: an SKA Precursor

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Murchison Widefield Array:an SKA Precursor Shep Doeleman - MIT Haystack For the MWA Project

  2. A wide-field, low-frequency imaging array • Optimized for wide FOV, high survey speed • Frequency range 80-300 MHz: Sample RF • Three key science goals • Epoch of Reionization • Solar, Heliospheric and Ionospheric • Radio Transients • Designed to exploit RFI-quiet site in Western Australia What is the MWA?

  3. The Partnership • Massachusetts Institute of Technology • Haystack Observatory (Project Office) • Kavli Institute • Harvard SAO • CSIRO (via synergy with ASKAP) • UMelbourne, Curtin, ANU (founding partners) • USydney, UTasmania, UWA, and others, ... • Raman Research Institute, India • Government of WA 3

  4. Murchison

  5. RFI Environment

  6. Antenna tile (~4m diam.) clusters Array (~1.5km diam.) tile Cluster (50-100m diam.) node Coax out Tile beamformer Fiber out Central Processing Physical Layout

  7. Production Dual-Pol Antenna 8

  8. Tentative Configuration Aperture Plane UV Plane

  9. Point Spread Function

  10. A/D Coarse PFB Select 30.72MHz 20 Tflops 32 single pol 192 fibers over 1-3km 1024 sig No Fringe Stopping 80-300MHz 524,288 sig pairs 18 Tera CMACs 10kHz resolution 0.5 sec accumulate 160Gb/s 2-10 Tflop

  11. Ionospheric Calibration

  12. Large N • Array configuration • Large data transport flow • Large multiplier for all processing • Correlator architecture • Calibration algorithms: real time • Cannot store raw data • Broad Science Case • Wide Field by design: transients • New analysis algorithms: EOR statistics • Links with solar, space weather community • Remote Site • International Project MWA as SKA Precursor

  13. September 08 to March 09 • 32-tile system: as of yesterday 16 tiles fully functional (w/ bf and rx). • Progressive testing of production hardware systems • Milestone for funds release, June 09 • April 09 to December 09 • Buildout to ~256 tile system • In-depth testing, refinement of algorithms • January 2010 to June 2010 • Complete buildout to 512 tiles • Initiate key science investigations • 2010 - 2012 • Refinement and incremental expansion • 2013 and beyond • Possible major expansion Schedule

  14. Murchison Widefield Array: Design 15

  15. Murchison Widefield Array: Specs

  16. Where and Why rHumans ~ 0.003 km2 Next Generation Heliospheric Imager Workshop, NSO, Sunspot

  17. Murchison Widefield Array 18 Next Generation Heliospheric Imager Workshop, NSO, Sunspot

  18. 32 Tile system: Specs Aperture plane uv plane

  19. MWA Current Status • A team is currently on site • 8 element interferometer to be set up by the end of April 08 • 32 element interferometer by July 08 • Major construction phase to begin shortly after that Next Generation Heliospheric Imager Workshop, NSO, Sunspot

  20. Murchison Widefield Array • Primary Science Objectives • Epoch of Reionization • Solar, Heliospheric and Ionospheric Science • Transients • Collaborating Institutions • MIT Haystack, MKI, CfA (NSF Ast and Atm, AFOSR) • 7 Australian Institutions • Raman Research Institute, India • ~20 MUSD Next Generation Heliospheric Imager Workshop, NSO, Sunspot

  21. MWA Science Goals • Epoch of Reionization • Power spectrum • Strömgren spheres • Solar/Heliospheric/Ionospheric • Faraday rotation, B-field of CME’s • Interplanetary Scintillation • Solar burst imaging • Transients • Deep blind survey • Light curves (field and targeted) • Synoptic surveys • Other • Pulsars • ISM survey • Recombination lines • Etc.

  22. The Epoch of Re-ionization • After ~300,000 years electrons and protons combine to form hydrogen • After ~1 billion years stars and quasars ignite, radiation splits hydrogen into protons and electrons. • In between are the Dark Ages

  23. Why is low freq radio astronomy suddenly so hot? • Huge advances in digital hardware  affordability of capable instrumentation • Enormous increase in affordability of computing (considering a few Tflops machine for MWA) • Considerable and continuing effort in development of calibration algorithms and techniques Next Generation Heliospheric Imager Workshop, NSO, Sunspot

  24. Key design considerations • High dynamic range imaging • Calibrability • Large number of interferometer elements • Full cross-correlation architecture • Full field-of-view imaging • Compact array foot print Next Generation Heliospheric Imager Workshop, NSO, Sunspot

  25. Sampler output • 1024 x 660 MHz x 8 bits = 5.3 Terabits/sec • Coarse Polyphase filterbank • Performed on full data rate in real time • Processing done by 512 Xilinx SX-35 FPGAs • Of order 20 Tflops, massively parallel • Post-filterbank • Aggregate rate transmitted over fiber: 330 Gb/s • Transmission distance = 1 to 3 km MWA Data/Computation Rates

More Related