The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen CSIRO Technologies for Radio Astronomy and The SKA PAF AIP 26 August 2016 CSIRO ASTRONOMY AND SPACE SCIENCE
Outline Current CSIRO PAF Development Ø ASKAP Ø Parkes 64m Bonn PAF (MPIfR) Ø Rocket PAF CSIRO PAF Development The Future SKA PAF Development SKA Survey PAF Dish Consortium Engagement PAF Advanced Instrumentation Program (AIP) SKA Observatory Development Program (ODP) Questions for the Future The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 2
ASKAP Australian SKA Pathfinder A Wide Field-of-View Radio Telescope Number of dishes 36 Dish diameter 12 m Max baseline 6km Resolution 10 (6km array), 30 (2km core) Sensitivity 70 m 2 /K Field of View 30 deg 2 Speed 1.5x10 5 m 4 /K 2. deg 2 Observing frequency 700 1800 MHz Processed Bandwidth 300 MHz Spectral Channels 16,000 Phased Array Feeds 188 elements (94 dual polarisation) The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 3
ASKAP Australian SKA Pathfinder Boolardy Engineering Test Array (BETA) Ø Decommissioned February 2016 Ø 6 antennas fitted with Mk. I Chequerboard PAFs Ø Conversion and baseband sampling at antenna ASKAP Design Enhancement (ADE) Ø 12 antennas currently operational Ø Mk. II Chequerboard PAFs Ø Direct sampling at central site The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 4
Parkes 64m Bonn PAF (MPI) ASKAP PAF (Mk. II) built by CSIRO for MPIfR Ø ASKAP Digitiser and Beamformer Ø GPU Correlator Ø Modified RF signal chain Additional filters (RFI) Commissioning on Parkes 64m antenna Ø Replaces Parkes multibeam receiver (13 beam) Ø Installed February 2016 Ø Commissioning and software development Ø Removal September/October 2016 The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 5
Rocket Array CSIRO Originated in CSIRO SKA PAF Program Initially focussed on 650 1670 MHz Common RF signal chain (SKA Bands 1, 2, 3) Reduced system temperature (T LNA ) Concept demonstrator Signal distribution Ongoing evolution of ASKAP feed package (Mk. II Mk. III Mk. IV) The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 6
Element and LNA Design Element based on a conical solid of revolution Edge elements designed to reduce the effect of the edge discontinuity Feed line loss minimised Balanced LNA Differential impedance 180Ω Commercial HEMT LNA TriQuint TQP3M939 & TQP3M9040 5 x 4 array constructed as proof-of-concept The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 7
RF Signal Chain Leverage off other developments SKA Common RF system architecture SKA bands (1, 2, 3) Ø RF over Fibre (RFoF) for signal transport (ASKAP) Ø Integrated 8 channel assembly completed and tested Ø Allows direct interfacing with ASKAP digital backend PAF1 Eelectronics 20 585.1 MHz 12.4 db RF chain with and without Equalizer LNA Amp FIL RFoF tx 10 0-10 646 MHz 6.32 db 1671 MHz 5.74 db PAF2 Eelectronics LNA Amp FIL RFoF tx PAF (Band) selection Pin Diode RFoF Receiver Amp FIL ADC To PPFB / BF -20-30 -40-50 DB( S(2,1) ) TxRx 30dBpad_without Equalizer DB( S(2,1) ) TxRx 30dBpad_with equalizer -60-70 PAF3 Eelectronics LNA Amp FIL RFoF tx Band control Simplified System Block Diagram (Y. Chung 2015) -80 0 500 1000 1500 2000 2500 3000 3500 4000 Frequency (MHz) Equal_3A_measured 0 Prototype RF Signal Chain Gain -1-2 -3-4 -5-6 -7-8 368.1 MHz -6.328 db DB( S(2,1) ) (L) Equalizer_3A DB( S(1,1) ) (R) Equalizer_3A 650.4 MHz -6.245 db 1153 MHz -5.51 db 1754 MHz -1.571 db 1672 MHz -2.331 db 0-2 -4-6 -8-10 -12-14 -16-9 -18-10 -20 200 400 600 800 1000 1200 1400 1600 1800 2000 Frequency (MHz) The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 8
Array Testing - Parkes The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 9
CSIRO PAF Development The Future Enhance existing Australia Telescope National Facility (ATNF) Instruments Collaboration and engagement with radio astronomy PAF community GPU based correlator development MPIfR PAF Reduction in PAF Tsys achieved incorporated into ASKAP Incorporate development from other projects Ø Next generation beamformer Ø High speed digitisation Continue rocket PAF development Cryogenically cooled PAF for Parkes Ø Rocket array element geometry Ø RFI/EMI considerations Ø Sampling at the focus Participate in SKA PAF AIP The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 10
SKA PAF Development SKA Survey CSIRO PAF Design Chequerboard array Australian SKA Pathfinder (ASKAP) Mk. II RF over Fibre signal transport 650 1670MHz band (SKA - Band 2) NRC PAF Design Credit: A. Chippendale, CSIRO Thick Vivaldi Array Advanced Focal Array Demonstrator (AFAD) Cryogenic cooling (CryoPAF) 1.5 4.0Hz band (SKA - Band 3) Credit: B. Veidt, NRC Canada The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 11
SKA Measurement Program The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 12
Performance Comparison Measurements calibrated using ASKAP (Mk. II) reference array. Gaps in the measurements are caused by RFI. The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 13
PAF Dish Consortium Engagement SKA Dish common optical configuration defined and dish design well developed (SKA SA, EMSS, NRC, CSIRO). Ø 15m Offset Gregorian Ø 5m sub-reflector (oversized) Ø Shaped reflector with 58 openning angle Ensure PAFs are not built out in SKA1_MID antenna design Ø SKA Feed Indexer design and structure interfaces Ø SKA_Survey Band 2 PAF replaces SKA SPF Band 1 Ø SKA_Survey Band 3 PAF (CryoPAF) replaces SKA SPF Band 3, 4, 5. Basic system architecture defined Draft PAF ICD under development Compatibility with SKA_Mid antennas The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 14
SKA PAF Advanced Instrumentation Program SKA Organisation agreed to set up a PAF AIP Ø Initial AIP Plan to SKA Board November 2016 Ø AIP runs for the remainder of SKA Preconstruction Late 2018 Ø System Requirements Review (SRR) and Conceptual Design Review (CoDR) Ø Precursor to PAF development program during SKA Construction (ODP) PAF AIP Consortium founding members Ø CSIRO Australia (Lead) Ø NRC Canada Ø ASTRON The Netherlands Ø INAF Italy Ø JBCO UK Additional members Ø JLRAT China Ø MPIfR Germany The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 15
SKA Observatory Development Program Role of the ODP To ensure ongoing instrumentation development Ø Ø Ø Ø Concept agreed but shape of program yet to be defined Cover ALL areas of development PAF, WBSPF, AAMID, Software, Managed centrally by SKA Organisation Funding model not decided (Fully funded or co-funded) ODP Proposals put to SKA Organisation on possible ODP Programs General agreement that PAFs are one of the key future technologies for radio astronomy and should be part of the ODP Key role of AIP program(s) is to do the ground work for the ODP The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 16
Questions for the Future Radio Astronomy in General Which niche/niches do PAFs fill in radio astronomy? What science will PAFs do better than anything else? Remember Scientists can be an impatient bunch; although they can see the potential; they will not wait forever Promising early science results What is the role of PAFs in the SKA? Key Areas of Technical Development Understanding on-dish performance Beamforming Algorithm, calibration, RFI mitigation, de-rotation Improving sensitivity Room temperature, cooled and cryogenic Bandwidth Observed and processed Manufacturability and cost Appropriate for the application The CSIRO Astronomy and Space Science Phased Array Feed Development Program Mark Bowen Page 17
CSIRO Astronomy and Space Science Mark Bowen Group Leader Front End Technologies +61 2 9372 4356 Mark.Bowen@csiro.au www.csiro.au We acknowledge the Wajarri Yamatji people as the traditional owners of the Murchison Radio Observatory site. CSIRO ASTRONOMY AND SPACE SCIENCE