Summary of Australian eVLBI activities

1
Summary of Australian e-VLBI activities

• Steven Tingay
• e-VLBI workshop, 31 May, 2004

2
e-VLBI Where is it at?

• JIVE/EVN experiments
• Real-time fringes with JIVE correlator
• First real-time image (May 2004)
• Haystack experiments
• Between various antennas, semi-regular real-time
  and delayed correlation of data (see Haystack
  e-VLBI memo series at ftp//web.ht.edu/pub/e-vlbi)
  
• Japanese experiments
• See Koyama-sans talk

3
Australian experiments/activities

• Have heard the science and business cases for
  ATNF e-VLBI project (appears to have high
  priority at ATNF)
• MNRF baseband processing project at Swinburne
• Development of PCEVN disk-based recorders for
  Australian telescopes
• Development of software correlator for VLBI
• Craig Wests Masters thesis
• Richard Dodsons work in Tasmania

4
LBA DAS
5
Summary of results

• First tests of recorder system at Parkes and
  Narrabri in November 2003
• Manual ftp of data and software correlation
• Fringes in about 15 minutes

6

• Global VLBI experiment
• April 2004
• Nine antennas (Tidbinbilla, Parkes, Mopra,
  Narrabri, Hartebeestoek, Kashima, Pie Town,
  Hobart, Ceduna) at 1.4 and 2.3 GHz
• PCEVN, MkV, and K5 disk-based recorders
• Mopra, Parkes, and Narrabri ran identical PCEVN
  recorders
• Automatic data transfer (Chris Phillips)
• Software correlation (West, Dodson, Tingay)
• Fringes within two minutes on a single baseline
  (Phillips/West)

7
The Near Future

• Craig is rewriting correlation code
• Pre-correlation fringe rotation
• XF or FX
• Stripped-down version for real-time
  fringe-checker
• Chris and Craig are making sure that their data
  transport and correlation code interact properly
• Further test observations in Australia using
  existing links to prove the software
• When? Directors time?
• Timescales for completion of software? Months?
• Timescales for completion of hardware? Months?
• When Gbit links come along, the software should
  be plug and play

8
Suggested short-term verification experiment

• In approximately 3 months (in August)
• Get some Directors test time ( few hours)
• Record 256 Mbps from Narrabri and Parkes using
  Swinburne recorders
• Use data transfer software (Phillips) software
  correlator (West) to undertake trial e-VLBI
  observation
• This is no different to the experiments that have
  been done in April, but the software needs to be
  developed considerably