APSRMatthew Bailes

Swinburne University Of

Technology

Baseband Pulsar Timing History

Caltech Berkeley Processor 1996 10 MHz 2xDLT 7000

Princeton Mk IV 1997 10 MHz 2xDLT 7000

S2TCI (~1997) York University/Melbourne Uni/Swinburne 16 MHz 8xVHS

CPSR1 (~1999) Caltech/Swinburne 4xDLT 7000

Baseband HistoryCOBRA

Coherent Baseband Recorder 2001?150+ Processors

CPSR2 (2002)2x64 MHz x 2bits x 2 pols30 Xeon dual processors

Arecibo Signal Processor (ASP) 03/04?64 MHz with polyphase filters and 4 bits

Selected Achievements

Princeton Mk IV MSP timing, ~200 ns timing on 1713+0747

PUMA2?? CPSR1

130 ns timing on PSR J0437-4715 CPSR2

Polarimetry of 27 MSPs Giant Pulses discovered in MSPs Precision timing on 7 MSPs (< 1 us) 0437, 0613, 1600, 1713, 1744, 1909, 1937 Several others near ~1 us

Giant PulsesGiant Pulse

2 microseconds wide!

Timing75 nanosecs

Stability

Profile PrecisionMust be done withCoherent dedispersion

New DFB Limitations2048 channels/ 512 MHzL-bandTerzan 5190 us Smearing!Still need coherent dedispersion

Current Generation

IF

IFSamplers+ FPGA

Bits

Polyphase bits

CPU 1

Gb ethernet

Gb SwitchCPU

CPU CPU

Next Generation “APSR”

ATNF/Parkes/Swinburne/Recorder 1 GigaByte/sec recorder/processor

Much higher timing precision Nanosecond pulse sensitivity

Lunar Experiments Giant pulses

Pulsar searches Polarimetry Spectroscopy VLBI correlator?

APSR

IF

IFSamplers+ FPGA

Bits

Polyphase bits

CPUs x16

Gb ethernet x16

Gb Switch144 ports minCPU x128

1 GHz x 2

SpecsLimited to 64 MB/s per host

Current Gb limit16 Primaries

64 MB/s2 bits x 64 MHz x 2 pols 3 GHz4 bits x 32 MHz x 2 pols L-band8 bits x 16 MHz x 2 pols Bright Pulsars

Primary Machines3 GB RAMGb ethernet x 2500 GB SATA disks16 of them

SecondariesLow-voltage next-gen Pentium2 GB RAM (min)2 x 250 GB SATA drivesProbably rack-mountedGb ethernet

Switch144 portsGb ethernet10 Gb uplinkProbably CISCO

CostingsPrimaries: 48 KSecondaries: 128 KSwitch: 12KCabling: 8KRacks: 15K

Total: 211K

Required Modes: Mode 1

Raw data x 162 bits x 64 Msamples/sec x 2 pols x 16 (agg 1 GHz)4 bits x 32 Msamples/sec x 2 pols x 16 (agg 512 MHz)8 bits x 16 Msamples/sec x 2 pols x 16 (agg 256 MHz)

Mode 2 Polyphase FB

2 bits x 64 MHz x 2 pols x 16 (agg 1024 MHz)4 bits x 32 MHz x 2 pols x 16 (agg 512 MHz)8 bits x 16 MHz x 2 pols x 16 (agg 256 MHz)

Required Modes: Mode 3

Polyphase FB - single host 2048 chans x 2/4/8 bits x Npol x 32 us sampling Up to 64 MB/s

Mode 4 Polyphase FB - multi-host

16 x PPFB x nbits x nchans x Npol x Nus samples Mode 4

As for 3, but incoherently dedispersed into N channels Mode 6

As for 4, but coherently dedispersed Mode 7

As for 3, but folded for N PSRs simultaneously Mode 8

As for 6, but folded for N PSRs simultaneously

Other Wishes:• New digital FB for next MB survey•13 DFBs with 300 MHz BW, 2048 channels, 64 us sampling

APSR16 Primaries

Switch

128 CPUs

10 Gb

To Grangenet

Ghz DFB 16?xDFB

IFs

13xIFs

GHz

AppleXRAIDs

16? lines

?

Aggregate PowerCPUs:

128 x 4GHz x 4flops/cycle = 2 TeraflopsDisk:

64 Terabytes (17 hours recording)Pulsar surveys in real time

Issues:Heat dissipation

144 x 150 W = 20 KW!!Multiplexing IO to CPUs

How can I take 1 GB/sec and spread it 16 ways without losing bits??

Upon Completion:Throw out:

CPSR2WBCDFB1MB correlatorsAnalogue FiltersVLBI recorders