meerkat dbe past present future

MeerKAT DBEPast Present Future

Alan Langman

28 September 2009

2

Overview

• Objectives of MeerKAT• MeerKAT Phase• XDM• KAT-7

– ROACH/katADC– Fringe Finder

• MeerKAT• Conclusions

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Objectives of MeerKAT

• Build a world class radio telescope (up to 80 dishes)• Choose a frequency range that is likely to have high

science impact.• Commission a 7 dish system from end of 2010,

engineering risk mitigation and do some early science. • Train a new generation of scientists and engineers who

are capable to participate in large international projects, such as the SKA.

• Provide an excellent facility for local and international scientists.

• Implement mission-driven innovation to mobilise industry, academia and research fraternity.

• SKA pathfinder (precursor)

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Definitions

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KAT element MeerKAT

SKA-SA: MeerKAT Phases

• XDM (Done)• Single Antenna HARTRAO• (PED)

• KAT7 (7 antennas Karoo)• Fringe Finder• Phase 1• KAT7• Optimization/Learning??

• MeerKAT (80 Antennas Karoo)

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eXperimental DeMonstrator

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Requirements

• Initially FPA/Multiple Feed (7 feeds)• Spectrometer

– 256MHz bandwidth– 2K channels– Minimum 100us dump time

• Radiometer• Histogram

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XDM: Plan A

ATX

12

Pow

er

Rel

ax

Com

pone

nt

Pla

cem

ent

Focus gateware and firmware on XDM Requirements

XDM: Plan B

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First Casper Solution

XDM Results08/27/08

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meerKAT-7

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Key Requirements

• Input signal – 72->328MHz, -27dBm (max 0dBm), NF=40dB

• Correlator/Beamformer– a) 1 band with total bandwidth >= 256MHz covering the whole

input frequency range, with equi-spaced channels of at least 1 MHz bandwidth each

– (b) 1 (goal 2 or 4) bands with total bandwidth >= 3.5 MHz selected from anywhere in the input frequency range, with equi-spaced channels of <= 10.7 kHz bandwidth each

– (c) 1 (goal 2 or 4) bands with total bandwidth >= 580 kHz selected from anywhere in the input frequency range, with equi-spaced channels of <= 530 Hz bandwidth each

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KAT-7 Block Diagram

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Key Component ROACH

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katADC (production)

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katADC Prelim results

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Mechanical Enclosure

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Detailed Design

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Key Component ROACH

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Production (always fun)

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Stress testing tool chainMillion channels, 512MHz BW, Single ROACH

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Fringe Finder -Risk Mitigation

• Fringe Finder (same base specs as KAT-7) – End of 2009

• Single baseline dual polarized correlator• Quad baseline single polarization

correlator.• 100ms dump time.

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Physical Solution

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FF Signal Flow

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Yet another PoCo

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Towards KAT-7 (Casper Collab)

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MeerKAT Key SpecsMetric KAT-7 MeerKAT

Pre-SACMeerKATPost-SAC

Flow 1.2 GHz 700 MHz 580 MHz

Fhigh 1.95 GHz 10 GHz 15 GHz

Ae/Tsys 16 m2/K 200 m2/K 200 m2/K

DRimag 30 dB 60 dB 60 dB

DRspec 30 dB 50 dB 50 dB

Xpol -20 dB -25 dB -25 dB

BW 256 MHz 1 024 MHz(2 048 MHz)

1 024 MHz(4 096 MHz)

Nchan 4 096 32 768 32 768?

Tint <1 s 0.1 ms 0.1 ms

MeerKAT Phasing

KAT-72010

Phase 12013

Phase 22014

Phase 32015

Phase 42016

Flow 1.2 GHz 0.9 GHz 0.9 GHz8 GHz

0.9 GHz8 GHz

0.58 GHz8 GHz

Fhigh 1.95 GHz 1.75 GHz 1.75 GHz14.5 GHz

1.75 GHz14.5 GHz

2.5 GHz14.5 GHz

BWRF 256 MHz 850 MHz 2 GHz 2 GHz 4 GHz

ADC 800 MSa/s 5 GSa/s 5 GSa/s 5 GSa/s 10 GSa/s

BWDIG 256 MHz 850 MHz 2 GHz 2 GHz 4 GHz

Bmin 20 m 20 m 20 m 20 m 20 m

Bmax 200 m 10 km 10 km 50 km 50 km

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MeerKAT Phasing

KAT-72010

Phase 12013

Flow 1.2 GHz 0.9 GHz

Fhigh 1.95 GHz 1.75 GHz

BWRF 256 MHz 850 MHz

ADC 800 MSa/s 5 GSa/s

BWDIG 256 MHz 850 MHz

Bmin 20 m 20 m

Bmax 200 m 10 km

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Block Diagram

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Key Challenges

• Digitization – Feed, Back Dish , Pedestal or correlator room

• Distributed correlator architecture• Timing and synchronization• Array Process/Backend Processor

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Conclusions

• Road to MeerKAT• XDM• KAT-7• ROACH development• Fringe Finder Risk Mitigation• MeerKAT challenge

Questions?