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ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

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ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team
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Page 1: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

ASKAP Capabilities

John Reynolds on behalf of the SEIC and ASKAP team

Page 2: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

• Design and construction well underway – many capabilities set

• To ensure highest priority science is delivered fluidity is retained

• Announcement of Opportunity, Oct 2008

• Proposals due in mid-June 2009, evaluation by Aug 2009

• Crystallisation thereafter towards BETR (2010), ASKAP (2013)

ASKAP Capability life-cycle

Page 3: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

• “Mode 1” capabilities already defined• Matching anticipated survey requirements• Continuum imaging• Standard spectral line imaging• Slow transients

• Post-commissioning• Advanced imaging modes (e.g. postage stamps)• “Zoom” (high spectral resolution) modes• VLBI & other “fast transients”

Rollout

Page 4: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

Original capabilities, EoI

Page 5: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

ASKAP Sensitivity (EoI)

Page 6: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

Basics

• 36 antennas (configuration by Gupta, Johnston, Feain 2008)

• 32 beams/antenna• 30deg2 FOV up to ~1.5GHz• 50K Tsys, 80% Aperture Efficiency • 300MHz instantaneous BW, 20 kHz frequency resolution• Frequency range 700 – 1800 MHz, • tunable in 16 MHz steps• Full polarization (auto/cross products on all beams)• 5 second integration time in standard mode

Page 7: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

ASKAP antenna design

12m – prime focus, f/D = 0.5

Alt+Az+polarisation axes (Sky mount)

Surface accuracy 1mm RMS (10 GHz)

Slew speeds 3/1/3 degs/secAcceleration 3/1/3 degs/sec/sec

Settling time < 5 seconds

Page 8: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

Typical u-v histogram for deep image

δ = -50ºT=10h

Page 9: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

PAF design

• 188 elements in octagonal configuration

• 32 x 2 pol formed beams

• Independently steerable

• 30 square degrees up to ~1.5GHz

• Optimal disposition for tesselation not entirely clear

• Interlacing (“dithering”) may be required for flatness of field

Page 10: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

Preliminary design of ASKAP-sized array

11x10 minus some corner elements

188 active pairs

Page 11: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

5 x 6 channel = 30 units13 x 8 channel = 104 units7 x 10 channel = 70 units

Available beams = 188

25 Multi channel LNA PCB's

Total number of LNA's = 204

188 channel FPA LNA Filtercard assembly

Page 12: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

FOV vs # beamsBeams touching at the 3dB points

Beams touching at the 3dB*0.92 points

Page 13: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

Overall ASKAP System

Beamfomer and Fine filterbank

Antenna 1

192 fibre connection

Beamfomer and Fine filterbank

Antenna 2

192 fibre connection

A/D and Coarse

FilterbankAntenna 36

Beamfomer and Fine filterbank

Antenna 36

192 Analogue

inputs

192 fibre connection

Correlator Band 1

Correlator Band 2

Correlator Band 16

Tied Array Post processing

(VLBI and Pulsars)

To Computing Centre

Central Site at MRO

Cross connect between

beamformers and correlator

Represents a single Advanced TCA

chassisAll Identical

To Computing Centre

To Computing Centre

To VLBI network

or pulsar processors

A/ Ds located in Antenna Pedestal

A/D and Coarse

FilterbankAntenna 36

192 Analogue

inputs

A/D and Coarse

FilterbankAntenna 36

192 Analogue

inputs

Page 14: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

Mode 1 imaging capabilities

Continuum1 channel + spectral index/curvature OR 256 spectral channelsFull Stokes parameters (IQUV)4k x 4k pixels (2km array) or 12k x 12k (6km array)Real-time source cataloguing

Spectral Line16384 channels (df=18kHz)2 Stokes (I, V)4k x 4k pixels (2km array)Visibilities not archivedLimited number of cubes per day

Slow transients snapshots : 16-channel, 4k x 4k pixel, 2 Stokes

searched every 5 seconds selected images retained

Page 15: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

Modes 2+

Advanced imaging Will be driven by Survey Science Project Design Study (2009-2011)

e.g. “postage stamps”, full 30dB polarization dynamic range

“Zoom” modes16k channels in 4~8 sub-bands, 0.6kHz(*2n) resolution, e.g.;

HI + 1612MHz + (1665-1667MHz)

VLBI – 2~3 tied-array beam voltages,

recorded off-site

frequency standard (H-maser vs Rb)

Fast transientsdiverse requirements vs fluid capabilities

active community consultation happening now

Page 16: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

Fast Transients – capabilities

Flexible correlator – access to; single-dish autocorrelations,

tied-array Voltages or Power,

visibilities (optionally averaging)

formed-beam voltages

flexible user-determined averaging, nStok, nBit …

some on-board capacity for processing, buffering

Constraints

on-site space, power limits & costs

bandwidth to Geraldton (40Gb/s initially, shared)

calibration (requires processing engine)

FPGA programming effort (+testing, commissioning)

Page 17: ASKAP Capabilities John Reynolds on behalf of the SEIC and ASKAP team.

CSIRO. ASKAP Capabilities

14 May 2009

The end


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