MPIfR Correlator Report ___________________________ MPIfR/BKG MKIV CORRELATOR =========================== GENERAL Current correlator capabilities are listed at: http://www.mpifr-bonn.mpg.de/EVN/MK4CORstatus CORRELATOR HARDWARE > 3 of the 4 Mark 5 units required for the upgrade to 12 stations have been procured (without backplane, I/O board, motherboard). The remaining parts, plus the 4th Mark 5 unit, will be purchased towards the end of 2005. It is hoped that this unit (with a new Streamstore card) will be able to sustain 1 Gbit/s transfer to Ethernet and 2 Gbit/s to disks. It would replace the Mark 5 at Effelsberg. > High-speed serial-links have been designed in a Haystack-MPI cooperation. A sufficient number for upgrading 3 MK IV correlators to 12 stations are being replicated. CORRELATION SOFTWARE > Data export to AIPS via MK4IN now works also under Linux. OPERATIONS > The correlator has no backlog. > The correlation factor of Mark5-only observations is close to 1. Hardly any re-correlation is needed except for modes with 31 MSamples/channel (a well known Station Unit problem). > Disks from EVN observations and mm-array sessions are recycled before the following session. On average 1 or 2 EVN observations per session are correlated at the MPIfR. > Correlation of 512 Mbit/s observations (standard for mm-observations), with 2 tapes per VLBA station and disks at European telescopes, worked smoothly without problems. > First disk-only mm-observations with 8 VLBA + 5 European stations have been successfully performed. > Data modulation with MK IV data format has been correlated successfully. (It had been switched on by mistake in Feb session.) > The first big 12-station spectral-line mm-observation with 1 frequency, both hands of polarization and 512 lags per channel has been correlated, resulting in a raw correlation data-set of 50 GB. > Fringe checks via ftp transfer are being done with Mark 5 systems and the correlator for mm-array observations. OTHER > A total of 100 MPIfR 8-packs have been assembled and added to the disk pool with a total capacity of 157 TB. W.Alef