development of difx
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Development of DiFX. Adam Deller NRAO 3rd DiFX workshop, Curtin University, Perth. Outline. Reasons for the development of DiFX Development of fxcorr (pre-DiFX) Rationale and planning of DiFX DiFX for the LBA DiFX at NRAO and elsewhere. DiFX: the raison d’etre. - PowerPoint PPT PresentationTRANSCRIPT
Development of DiFX
Adam Deller
NRAO
3rd DiFX workshop, Curtin University, Perth
Adam Deller 3rd DiFX workshop, Curtin University, Perth
Outline Reasons for the development of DiFX Development of fxcorr (pre-DiFX) Rationale and planning of DiFX DiFX for the LBA DiFX at NRAO and elsewhere
Adam Deller 3rd DiFX workshop, Curtin University, Perth
DiFX: the raison d’etre In 2004, the LBA installed new disk-based
recorders capable of 4x the bandwidth of the S2 tape system
The existing hardware correlator could not interface to the new recorders
Required: a “stop-gap” solution before the CABB correlator for ATCA was ready for VLBI data
QuickTime™ and a decompressor
are needed to see this picture.
The S2 correlator
Adam Deller 3rd DiFX workshop, Curtin University, Perth
DiFX: the raison d’etre
Adam Deller 3rd DiFX workshop, Curtin University, Perth
2005: Development of fxcorr My PhD began February 2005 - first attempt
was FX-style correlator which ran on a single node (distribution via scripts/data division)
Naivete in both C++ and correlators led me to build in some idiosyncracies/inefficiencies
Verified against S2 results, but plans made to redesign from scratch, using data distribution with MPI - mpifxcorr, copy/pasting the internals of the correlation code
Adam Deller 3rd DiFX workshop, Curtin University, Perth
Rationale/planning of DiFX At this stage, plans made to support other
formats than LBA (specifically Mark5) Attempted to not “design out” any general
applications, but the main focus was nevertheless on LBA operations
Also made provisions from the outset for eVLBI connections into the correlator
Main development was complete by mid 2006
Adam Deller 3rd DiFX workshop, Curtin University, Perth
DiFX at the LBA DiFX has been the production correlator of
the LBA since end of 2006 Plans to use the CABB correlator as the LBA
correlator have been shelved 2008: Correlation moves from Swinburne to
Curtin Oversubscription rate has risen substantially
since DiFX + LBADR (recorders) introduced - maybe ~1.5 to ~3??
Adam Deller 3rd DiFX workshop, Curtin University, Perth
Science highlights at the LBA First trans-Tasman fringes - to a 6m dish in
NZ!
Adam Deller 3rd DiFX workshop, Curtin University, Perth
Science highlights at the LBA First trans-Tasman fringes - to a 6m dish in
NZ! First southern hemisphere eVLBI, detecting a
flare in Circinus X1
Adam Deller 3rd DiFX workshop, Curtin University, Perth
Science highlights at the LBA First trans-Tasman fringes - to a 6m dish in
NZ! First southern hemisphere eVLBI, detecting a
flare in Circinus X1 6 new pulsar
parallaxes, trebling the number of Southern pulsar parallaxes
Adam Deller 3rd DiFX workshop, Curtin University, Perth
DiFX at the VLBA VLBA sensitivity upgrade has been an
ongoing project that requires a new correlator to deal with increased data rates
DiFX selected in 2008 Going “live” this proposal cycle - first element
of the upgrade (backends and recorders to come) to do so
Huge amounts of streamlining and infrastructure have been contributed by the NRAO efforts
Adam Deller 3rd DiFX workshop, Curtin University, Perth
DiFX worldwide DiFX is likely to replace three other existing
hardware correlators: Bonn, USNO, Haystack This is the third DiFX workshop - attendance
has gone from about 8 to about 12 to about 24 - the last year especially has been an exciting time development- and adoption-wise
Lets keep this thing rolling!