Westerbork station report to TOG
VLBI Hardware
- Mark 5 recorders
- Westerbork bought two Mark5 recorder systems from Conduant.
One has gone to JIVE and the other remained in Westerbork,
and the Westerbork unit has now had a fibre gigabit
ethernet card installed. The 2 recorders came with
2 empty disk packs and Harm-Jan Stiepel installed
8x180Gbyte IBM/Hitachi drives in each
- Mk5 Disk packs and Disks
- Westerbork bought 34 extra empty disk packs from Conduant,
and 160 180Gbyte IBM/Hitachi disk drives to fill 20 of them
(although only 19 have been assembled).
- Terminator boards
- We installed the terminators to the outputs on the
Mark5a recorder
- Dedicated eVLBI fibre
- Westerbork has 2 distinct
gigabit ethernet fibre connections to Dwingeloo
since March 2004. One is a general purpose line for data
communication and the other is a dedicated eVLBI connection
between the Westerbork Mark5a terminal and one of the JIVE
Mark5a units. The Westerbork side is connected to the
(Alteon Networks Inc. AceNIC) gigabit ethernet card,
and the onboard 100Mbit card is used
for control and communication with the field system.
The dedicated line is not switched so that the general traffic
is not disturbed by eVLBI. Some eVLBI tests that used the
general purpose line did disturb users in JIVE and ASTRON.
- Disuse of Mark4 recorder.
- During VLBI Session 2004-1 no tape recordings were done.
Observations were all recorded via the Mark5a unit, although
some eVLBI tests were done using it to route the data (via the
general use line) to JIVE.
The Mark5a proved very reliable although some minor problems
did occur.
Field System
Only minor changes were made to the field system. The system was updated
to FS 9.6.9. A few alterations were made in the interfaces used by the
single-dish VLBI setup to conform with local network and software changes.
System
- 5cm methanol receiver
- The single 5cm reciever ( for methanol maser observations) was
installed and tested after Session 2004-1. Local tests of
sensitivity gave a telescope gain of 0.060 K/Jy and
system temperature of 97K (SEFD=1600Jy). This is much
closer to the 3.6cm system values than the 6cm system
values.
This reciever gave fringes in the test observation
F04M1 and local (autocorrelation) observations confirmed
that we can observe maser lines.
Future
- Fully digital tied array
- I want to present an update on how that is progressing
Tony Foley (foley@astron.nl)
Last modified: Thu Mar 25 15:14:07 2004