MPIfR Correlator Report (November 2005)
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MPIfR/BKG  MKIV  CORRELATOR  
===========================     

GENERAL

   Current correlator capabilities are listed at:
        http://www.mpifr-bonn.mpg.de/EVN/MK4CORstatus
  

CORRELATOR HARDWARE

   > 4 Mark 5 units required for the upgrade to 12 stations have been
     procured (without I/O board, main-board). 8 upgrades to Mark 5B
     have been ordered from Haystack; 2 more will be delivered via the
     Mark 5 consortium agreement. The remaining upgardes will have to
     be bought from Conduant. The decision on main-boards is
     pending. The aim is to buy main-boards which can fully support 1
     Gbit/s. 

   > The required correlator interface boards will be delivered by
     Haystack presumably early next year,

   > A sufficient number of high-speed serial links to upgrade 3
     correlators to 16 stations have been built and were tested
     successfully.  High-speed serial-links are needed for the data
     transmission between the correlator interface boards and the
     correlator.

   > The 12 Mark 5 units together with correlator interface boards
     will be mounted in 3 racks. They will be incorporated into the
     correlator system early next year.

   > 2 tape drives will be removed from the correlator at the end of
     the year. 


CORRELATION SOFTWARE

   > A path for tropospheric path length corrections into the
     correlator data has been realized. The corrections are applied
     before the data is read into AIPS (for FITS export).

OPERATIONS

   > Thick tape recordings from Crimea are still received and
     correlated. 

   > All astronomical observations are now disk-only. To record the
     last session of the global mm array, NRAO was provided with about
     80 TB of disk space. This allowed to nearly double the duty cycle
     of the VLBA at 512 Mbits/s (equivalent of about 4 thin tapes per
     day).

   > 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.


OTHER

   > A total of 111 MPIfR 8-packs have been assembled and added to the
     disk pool with a total capacity of 197 TB.

   > A 2nd Mark 5(B) unit has been purchased for Effelsberg. It will
     be connected to the VLBA terminal, and will thus also allow EVN
     observations to be done with the superior continuous calibration
     scheme available with VLBA terminals and the VLBA control
     software.

   > When both Mark 5 units will haven been upgraded to Mark 5B,
     recordings with nearly 2 Gbits/s will be possible. 



W.Alef