EVN Technical and Operations Group

The Technical and Operations Group (TOG) is made up of the personell at the EVN stations who provide the technical and operational expertise for operating the EVN as a VLBI array. They are also responsible for advising the EVN Consortium Board of Directors on all aspects of technical and operational issues relevant to the reliability and performance of the network. The TOG is also the body which implements technical and operational upgrades across the network.

The chairman of the TOG is Michael Lindqvist (OSO, Onsala).

Latest news on EVN developments

• Onsala has tested their DBBC successfully in session 3/2011. Yebes has received a Mark5B+ so that soon they can also take part in 2 Gbps tests. A DBBC was delivered to Torun.
• At Effelsberg a DBBC was in use as primary VLBI backend during the recent May/June 2011 EVN session and for eVLBI runs. Following the successful outcome of the geodetic EUR112 observation in June 2011 and of the test in PFB mode with Onsala with a datarate of 2 Gbps which followed shortly after it, Effelsberg plans to remove the MkIV terminal this autumn and use the DBBC exclusively in future. It is expected that Onsala will be the next EVN station to switch to the DBBC and offer 2 Gbps.
• The EVN will start testing recording at 2 Gbps in the first half of 2011.
• During the Feb/Mar 2011 session Effelsberg used a DBBC (digital BBC) with Mark 5B+ in parallel to the old analog backend hardware. JIVE reported very good results in a preliminary analysis of a small portion of the data. Check for instance the feedback of N11C1.
• The EVN directors decided to implement 4 Gbit/s recording in the EVN
• A small subgroup was formed to prepare a proposal for implementing 4 Gbit/s data acquisition systems in the EVN.
• VLBI continuum observations are now mostly recorded at 1 Gbit/s. EVN directors have agreed to increase the disk pool to allow all continuum observations to be recorded at 1 Gbit/s datarate (2007).
• Amplitude calibration has been improved. Careful analysis of the calibration data provided by the stations revealed problems that could mostly be solved during 2006. Continuous TSYS measurements are done at all stations. Automatic off-source data flagging has been implemented for all stations.
• Network verification via ftp data transfer is regularly done for improved network reliability.

Other information

• The EVNtech E-mail exploder, the main way Technical and Operational information is shared and communicated within the EVN.
• The TOG Wiki pages can be found here. Please contact Walter Alef for an account.
• Minutes of the EVN TOG.
• The next TOG meeting will be held at the Onsala Space Observatory around May, 2012.
  
• The last TOG meeting was held at the National Astronomy and Ionosphere Center, Arecibo Observatory, Puerto Rico, August 29/30, 2011.
  
• Network Performance and EVN Feedback Pages (Telescope Reports by Experiment)
• VLBA feedback pages (Telescope performance via sniffer plots, by Experiment)
• A description of the use of GPS measurements at EVN stations, including the format for GPS logs deposited on VLBEER.
• Here you can find the EVN Mark 5 disk inventory.
• EVN Operations web page (inc. archives of the EVN TOG Mailing-Lists: EVN performance, calibration, recorder maintenance, formatters, polarisation, RFI, logistics etc.
• A list of Obsolete VLBI Components maintained by Paul Burgess (JBO) and some possible alternatives.
• The Bologna Rules - a code of practice adopted by the EVN telescopes w.r.t. all logistical matters (tape shipment, deposition of logs etc).
• EVN Technical Document Series: copies can be obtained by mail from the JIVE Secretariat.
• Foam specs for Mark 5 packaging foam as provided by Haystack.