Table of contents
# report.txt
# report on the 2011 Apr 11--12 LOFAR Technical Operations Meeting in Dwingeloo
# 2011 Apr 19 James M Anderson --MPIfR start
Original agenda:
12:30-13:30 lunch (Hooghoudt room)
13:30-17:00 Welcome
Short overview of main developments and events since the
previous ILT TO meeting
Overview of expected events in the coming year
Role of the LOFAR Commissioning Coordination group
(LCCG)
Station operation; ILT (array) mode and stand alone
mode, station monitoring
Station maintenance: station test, repairs, spare parts,
experience gained, container maintenance
Information exchange: teleconferences, meetings, wiki's,
issue trackers
wrap up
18:30- Dinner in Dwingeloo
Tuesday, April 12 (ASTRON antenna test field, Multimedia room)
9:30-12:00 Hands on workshop antenna repairs
Wrap up
12:30-13:30 Lunch (ASTRON canteen)
This was the second LOFAR Technical Operations Meeting. The previous
meeting was held one year ago, and was attended by W Reich and K
Schlich from Bonn (was there someone else too?). Attending were
JM Anderson Ef MPIfR
A Horneffer Ef MPIfR
M Kuniyoshi Ef MPIfR
D McKay Cb (EVO)
M Jahn Jü Bochum
E Middelberg Jü Bochum
L Helldner On
T On
B Ciardi Uw MPA (EVO)
M Hoeft Tb (EVO)
H Munk ASTRON
T Grit ASTRON
M Norden ASTRON
C Vogt ASTRON
H Meulman ASTRON
A Polatidis ASTRON
No representative from Nancay was present.
(For some reason, Ralf Kisky <rkisky@mpifr-bonn.mpg.de> was on the
e-mail list, although I have no idea who this person is. 100 m
operator?)
Web/wiki pages of interest
Overview of single station use:
http://www.lofar.org/operations/doku.php?id=singlestation:start
ILT LOFAR Operations Overview
http://www.lofar.org/operations/doku.php?id=operator:operations
International Station Contacts
http://www.lofar.org/wiki/doku.php?id=operator:ilt_to_contacts#international_stations_contacts
Meeting notes:
Station Construction:
6 new stations were built in the Netherlands since 2010 April, 4 new
Core stations and 2 new remote stations. 7 of the International
stations are finished or nearly finished (Juelich still needs to
construct the LBA field, to be done on 2011 April 20). Onsala still
needs to be constructed in 2011. 7 NL stations are waiting to be
constructed, ASTRON does not expect to start construction on them
until after the summer break. (I expressed scepticism that they will
be able to finish construction this year, if they start only in late
September.) Potsdam-Bornim finally has a working network connection,
and the connection to Juelich is being tested.
The network connection for International stations within the
Netherlands needs to be upgraded. 2 additional 10 GE lines from
Amsterdam to Groningen need to be installed. An additional 10 GE line
from Aachen to Amsterdam is needed. Note: when the EVN goes to 4 Gb/s
data links, the planned 2 time 10 GE lines from Aachen to Amsterdam
will not be sufficient. Also, should the Hamburg station be built,
there will be no room at all for eVLBI on the Aachen to Amsterdam
link.
ASTRON is investigating the possibility of implementing a common clock
for the LOFAR stations attached to the concentrator node in the
Netherlands. In the future it may be possible to extend this to other
stations.
There are no spare parts. ASTRON used up all spare parts when it
built the 4 additional Core stations in 2010 which were not in the 36
station plan. ASTRON will have another round of manufacturing of
spare parts done to generate spare parts for things LOFAR expects to
need. An inventory of part failures is needed. Note that the
Effelsberg station uses different parts for some of the electronics
boards and possibly LBA antenna parts. The ASTRON engineers do not
want to mix old electronics boards with new electronics boards, so for
the foreseeable future, there will be no spare parts for some of the
Effelsberg station components, and any failures will have to be
repaired. This is known to include the RCU boards, of which the
Effelsberg station has 192, and > 16 have failed in the past 18
months. See action items 1 and 2.
The Effelsberg antenna positions in ETRF or ITRF (x,y,z) need to be
re-measured. See action item 3.
A document describing all of the procedures station managers are
expected to be able to perform on their stations will be produced.
Input on things that are needed to be able to be done is requested to
be sent to H Munk. For Effelsberg, I want to turn many of the
responsibilities for initial and emergency contact for the Effelsberg
station by the ILT Operations to the 100 m operators. See action
items 4 and 5.
Some of the known failure modes for parts were discussed. Effelsberg
has a problem with the humidity being too low during winter months.
RCU board failures, and possibly the rubidium clock failure may be
caused by this problem. Electronics boards inside of the HBA tiles
are failing because of high humidity conditions at other stations.
Apparently the protective coating applied to the boards was defective.
In cold weather, the HBA rubber tie-down straps become stiff and do
not hold the HBA tile covers down. Inspections need to be done to
check that all tie-down straps are secure. Also, many problems are
seen following wind storms. Animal destruction of antenna parts is
also seen at most stations. Regular inspections of the Effelsberg
station are needed. See action item 6.
Additional minor issues were discussed. See action item 7.
On Tuesday, April 12, we were given a demonstration and practice
session for repairing antenna parts for the LBA and HBA antennas.
AH, MK, and JMA took part in this exercise. In the event that antenna
repairs are needed, especially for the HBAs, one of them should be
contacted.
Action Items:
1. Spare parts. JMA, AZ. Write up spare parts details into Ef-ILT
station contract.
2. Spare parts. JMA, AH, KS. Check inventory of parts with ASTRON to
see which parts we can share with new stations.
3. Antenna positions. Contact Axel Nothnagel to have the Effelsberg
antenna positions measured in (x,y,z) coordinates for ETRF or
ITRF.
4. Ef Operations Meeting. JMA, AK, MK, AH, MK. Meeting to discuss
coordinating operations of the Effelsberg LOFAR station with the
100 m operations group.
5. Training Session. JMA, AH, AK, 100 m operations. A training
session to teach the 100 m operators how to do basic things with
the Effelsberg station, such as logging into the station control
computer and emergency power shutdown procedures.
6. Visual station inspections. JMA, AK, Ef staff. Visual inspection
routines for the Effelsberg LOFAR station need to be implemented.
Persons at Effelsberg need to be trained to inspect the station
for problems. A weekly and a monthly inspection process, needs to
be developed and implemented. Inspections following stormy
weather are also needed.
7. Effelsberg miscellaneous issues. JMA. Replace metal pins in the
HBA field. Diameter of the LBA poles. Cable torque wrench.
Station control transfer software. Whitelist for lofarX
computers.
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