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
3
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)
4
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
AT
X12
P
ower
Rel
ax
Com
pone
nt
Pla
cem
ent
Focus gateware and firmware on XDM Requirements
XDM: Plan B
11
First Casper Solution
XDM Results
08/27/08
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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 chain
Million 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?
