Kashima-WSRT fringes via the KSRC/NICT VLBI software correlator

We have succeeded in obtaining good fringes on the Kashima-WSRT baseline using the software correlator developed by the Kashima Space Research Centre (KSRC) of the National Institute of Information and Communications Technology (NICT) in Japan. The VLBI data used in the correlation was obtained during N03L1 (25/2/2003) - the L-band NME (see also First EVN image using MkV-MkV baseline data). Mk5 data were recorded at the WSRT and K5 data were recorded at the NICT Kashima telescope.

The diagram presented above is the detected fringe of DA193 in the delay--delay rate search window. 16 seconds of data recorded with the Mk5 system (256Mbits/s, 8MHz, 8 BBCs, 2bits/sample) were transported via FTP from JIVE to KSRC (~1Mbytes/s, ~570Mbytes). Then they were converted to the K5 formatted data to make the correlation with the K5 data. The software correlation was performed on a LINUX machine with a Pentium III 800MHz processor and the fringe was found within 10 minutes (including data conversion, fringe stopping, fringe search and drawing the search window with PV-WAVE).

In principle, the software correlator can be used to continuously monitor the reliability of the European VLBI Network (EVN) and other VLBI networks without disrupting production correlation at JIVE. Also, KSRC's VSSP (versatile signal sampling processor) backend unit is now compatible with the EVN's Mk4 backend.

Questions should be directed to Tetsuro Kondo (KSRC/NICT, kondo@nict.go.jp) or Zsolt Paragi (JIVE, zparagi@jive.nl).