Westerbork VLBI report for TOG 22 September 2008 ================================================ Regular Session Participation: Westerbork participated fully in sessions 2008-1 and 2008-2. Observing was mostly successful, with only 3-4 hours lost to technical problems in each of the sessions. A complete overview of all experiments in these 2 sessions is given at the end of this report. e-VLBI: Westerbork performed well during e-VLBI observations and tests (see http://www.expres-eu.org/evlbi.html) The 34.4 km dark fiber between Westerbork and JIVE was recently upgraded to use multiple wavelengths(CWDM), with each wavelength able to carry 1 Gbps. Tied Array: The new (fully digital) tied array hardware (TADUmax) is nearing the end of commissioning. Apart from a few specific points, the first successful fringe test, conducted with thanks to the staff in Torun and at JIVE, showed high quality data. It is now likely that we will take TADUmax into operation for session 2008-3. One of the consequences of using the TADUmax is that we have to use more different frequency setups for our backend. So we need more time to phase up the array. (With the Mark4 we could do different experiments with one backend setup, by changing only the VC settings.) We expect that we need 10-15 minutes, for phasing up the array in the gaps between experiments. So we would appreciate gaps of at least 30 minutes (slewing included) between experiments in the schedule. Another consequence of using TADUmax is that we need to use the Mark5B iso Mark5A. Single Dish: No changes. Field System: We upgraded successful to FS-Linux 7 (Raid 1) and installed FS9.10.3 Also the old FS spare computer with two 4.5 GB disks was upgraded to FS-Linux 7 Acquisition Rack: No major changes Mark5A: The Mark5A performed well. It was upgraded with a new motherboard. A problem is that all the real time fringe tests had to be done manually, using byte offsets, because the automatic procedure to process a fringe-find file, does not work. This is still not solved. Other: Due to the fact that all Westerbork staff is moved to another site (Dwingeloo), a lot of effort was made to make all the systems in Westerbork ready for remote control. All the WSRT observations are now controlled from the controlroom in Dwingeloo. In the near future also the VLBI operations will be done from there, but for session 2008-3 the 3 operators will be on the WSRT site. Overview of all the experiments in session 2008-1 and 2008-2 ----------------------------------------------------------- Session 2008-1 6 cm (ToO) Paragi GP046A ;TiedArray mode; lost 14 minutes due to DZB hardware problem (IVC); IFD could only do manual settings 18 cm (all tied array) JIVE N08L1 ;started slightly late; real time fringe test by hand iso automatic Gunn CL08L1 ;RFI Giroletti EG037C ;ok Perez-Torres EP061A ;one diskpack had a wrong label due to double pack SSERASE; solved at JIVE Perez-Torres EP061B ;one diskpack had a wrong label due to double pack SSERASE; solved at JIVE Brunthaler EB037A ;one diskpack had a wrong label due to double pack SSERASE; solved at JIVE Lobanov EL034B ;one diskpack had a wrong label due to double pack SSERASE; solved at JIVE Szymczak ES058 ;one diskpack had a wrong label due to double pack SSERASE; solved at JIVE Asada EA036B ;one diskpack had a wrong label due to double pack SSERASE; solved at JIVE de Vries GV019A ;some RFI 1.3 cm (no wsrt requested) JIVE N08K1 Gunn CL08K1 Moscadelli EM059C Brunthaler BAH09 Brunthaler EB037B 3.6/13 cm (tied array,only 3.6cm available(no multifreq) phase stability sometimes poor) JIVE N08SX1 ;only 3.6; real time fringe test by hand iso automatic Gunn CL08SX1 ;no wsrt requested Charlot GC030 ;no wsrt requested Charlot GC025B ;ok 6 cm (tied array) JIVE N08C1 ;ok Giroletti EG037D ;ok Perez-Torres EP061C ;lost 47 minutes due to real time control system problems(wop28 died). Perez-Torres EP061D ;lost 2 hour and 54 minutes (RT system wop28 died). Cimo EC026 ;ok Gunn CL08C1 ;stopped twice due to strong winds (lost ~ 2hour) de Vries GV019B ;ok 5 cm (single dish) JIVE N08M1 ; BBC1 unstable' real time fringe test by hand iso automatic Gunn CL08M1 ; BBC1 unstable Moscadelli EM069A ; BBC1 unstable Moscadelli EM058B ; BBC1 unstable Moscadelli EM069B ; BBC1 unstable Brunthaler GB063B ; BBC1 unstable Moscadelli EM069C ; BBC1 unstable 6 cm (ToO) Paragi GP046B ;ok Session 2008-2 1.3 cm (wsrt not requested) JIVE N08K2 Gunn CL08K2 Brunthaler EB037C Muehle N08K3 Miller-Jones GM064 18 cm (tied array) JIVE F08L1 ;RFI Szymczak ES057B ;bad RFI Biggs EB038A ;some RFI and thunder(lightning) Overzier EO006A ;lost 25 minute due to false storm alarm JIVE N08L2 ;some RFI. Real time fringe find test failed Gunn CL08L2 ;RFI Perez-Torres EP061E ;RFI Biggs EB038B ;ok Overzier EO006B ;RFI Perez-Torres EP061F ;ok Wucknitz GW019A ;ok Overzier EO006C ;ok Amiri EA038 ;RFI 6 cm (tied array) JIVE F08C1 ;ok Conway GC031A ;ok JIVE N08C2 ;real time fringe test by hand iso automatic Gunn CL08C2 ;ok Perez-Torres EP061H ;lost 31 minutes due to array problem Liu EL036A ;ok Perez-Torres EP061G ;ok 5 cm (single dish) JIVE N08M2 ;real time fringe test by hand iso automatic Gunn CL08M2 ;ok Brunthaler GB064A ;ok Vlemmings EV017 ;ok Brunthaler GB064B ;ok Sjouwerman GS029 ;ok Brunthaler GB064C ;lost 2.5 hour due to wrong receiver steering (TMS took over single dish after reboot)) Brunthaler GB064D ;ok lost in session 2008-1 : 3 hours and 57 minutes (mainly due to a broken real time computer wop28) lost in session 2008-2 : 3 hours and 26 minutes (mainly due to the fact that the TMS system took over the single dish receiver steering after a weekly routine reboot) G. Kuper 29-8-2008