Summary of the GMVA Session, May 19 - 23, 2016 ============================================== General: ======== The following stations participate in the session: Effelsberg, Onsala, Yebes, Metsahovi, Pico Veleta (only c161a), P. de Bure (only c161a), the GBT and the VLBA. The weather in Europe was mixed, good conditions in Spain, moderate good in Germany and Skandinavia. In nothern Europe the weather degraded towards the end of the session. European stations tried to record using DBBC2 and Flexbuff with a new version of the field system. There are still issues with this configuration, which is not stable. Fringetest on May 19 reveals fringes between Eb-On-Ys Polarisation is swapped for On and for Ys. Note: After observation PdB detected a broken 1pps connector on the FS. Most likely will not see fringes to PdB. Note2 during fringesearch: V-shape amplitude pattern detected on Ys, Pv and Ef. This is a bug in the firmware of the DBBC (/dbbc/version/PFB,15_2). Individual Station comments: ============================ Eb: some scans affected by bad DBBC statistics in one of the two IFs (polarisations), unclear how this affects data. weather: mixed, clear portions but also clouds and rain (rain mainly at the end of the session on Sunday to Monday night). 19.5 start c161a in time, clear sky, Tsys 200K, tau~ 0.2 20.5 bad weather during daytime, many clouds, pointing is difficult >18h00 UT clearing up, weather good, pointing good 21.5 04 UT: last night was calm with clear skies 22.5 08 UT: last night was good again, BLLAC is too faint for pointing on it 23.5 18 UT: rain, thick clouds, 0716+71 not visible 24.5 02 UT: overcast, light rain, configuration of MK6 recorder not recording Pico: Observed in good weather (c161a) did not participate in c161b PdB: joins only c161a, but not c161b cannot start in time, high wind, join c161a at 00:34 UT, excellent conditions, phases are stable. after session discover broken 1pps contact on formatter On: runs 2 backends in parallel: (1) DBBC2 and MK5B+. (2) DBBC2, FILA10G, and Flexbuff (FILA40G) (may have problems) Ys: observing with good weather Mh: A short summary from Metsähovi: The weather was clear during the both sessions (c161a and c161b). c161a: We had a wrong dbbctrk1 order at the beginning, thus we missed L-polarization data. This was fixed on Friday afternoon. c161b: We missed 4 hours of data on Saturday afternoon (around 11-15 UT). Our procedure file didn’t include ”bank_check” command, thus when diskpack in bank A was full, it didn’t swap automatically to bank B. GBT: The Tsys on the LL channel appears to be considerably higher than on RR. for the SgrA part the weather was good (tau=0.14-0.18), for the M87 part, the weather was bad (tau=0.4-2.0), for the ALMA test part the weather was reasonable again (tau=0.4-0.5) VLBA: receiver problems with MK, station lost Project: C161A Observer: Krichbaum, T. Project type: VLBI Obs filename: c161acrd.* Date/Day: 2016MAY20/141 Ants Scheduled: NL FD LA PT KP OV BR MK GB =UT-Time===Comment===============================================MF#===%AD==AMD= Operator is Paul Padilla UT1-UTC: -0.17, VClock: 0.016, GPS delta: -7.0 0257 Begin 0354-0446 *PT,MK out for daily USNO observation SCH 200 104 0541 Operator is A. Sowinski. 1015-1710 *MK Cryo 'A' compressor failure. Both 7mm and 3mm CRYO 100 415 receivers are starting to warm up. Downtime not initially 100%. 1100 &MK Calling site tech. C138217. 1224 SC wea: light scattered low clouds, dry. 1241 FD wea: clear, calm, dew on dish. 1345 New Operator: Karlee Radford 2107-2123 *MK site tech needed on the antenna. CRYO 100 16 2150 New Operator: Paul Padilla 0537 Operator is A. Sowinski. 0645 %BR Raining. 0710 KP Windy. 0907 End at OV,BR. 0910 Observation vex files ended slightly before VME files. 0910 End. Downtime Summary: Total downtime : 535 min Percentage downtime of observing: 17.9% Average downtime per hour : 10.8 min Total scheduled observing time (# Antennas): 2984 min (8) c161b: Project: C161B Observer: Krichbaum, T. Project type: OTHER Obs filename: c161bcrd.* Date/Day: 2016MAY21/142 Ants Scheduled: NL FD LA PT KP OV BR MK =UT-Time===Comment===============================================MF#===%AD==AMD= Operator is A. Sowinski. UT1-UTC -0.17; gps delta and vclock okay. 0912 Begin, except at MK. 0912-0914 *BR DBE1 timing errors. Cleared by restarting TIME 100 2 the Executor. 0912-1002 *PT currently running USNO N6142. SCH 100 50 1003-1006 *PT DBE1 timing errors. TIME 100 3 1051-1508 %BR Raining. 1123-1124 *KP Autostow, repointed. COM 100 1 1200 Begin at MK. 1345 New operator is Alan Kerr 2011-2030 *MK stowed. Site tech needs to access a cryo. CRYO 100 19 2054-2107 *MK stowed. Site Tech finishing cryo work. CRYO 100 13 0000 Date is 2016MAY22/143. 0152 New operator is Betty Ragan. 0230 %FD RCP 3mm tsys are elevated. 0245 %OV windy. 0320-0327 *PT has TimestampSyncError alert on DBE-1. TIME 100 7 0428-0437 %BR raining. 0440 %OV windy. 0535-0538 *PT, MK VMEs were rebooted to get them to accept SCH 200 6 changes to the USNO file that will run in a few hours. 0600 %KP windy. 0608-0609 *KP autostowed. Power glitch. COM 100 1 0610-0611 *KP stowed again. COM 100 1 0654-0656 *KP 55 mph wind stow. WEA 100 2 0706-0707 *KP stowed. Power glitch. COM 100 1 0711-0714 *KP stowed again. COM 100 3 0712-0715 *LA getting very high AZ motor currents. ACU 100 3 Put it in standby and repointed, and it looked OK after that. 0725-0727 *KP wind stow. WEA 100 2 0755-0847 *PT removed for USNO observation. SCH 100 52 %PT may experience delay and phase jumps when rejoining the observation. 0755-0807 *MK observation not running on the VME. HUERR 100 12 It was removed for the USNO run, but will not be used for it. Observing was restarted. 1005-1008 *OV has TimestampSyncError alert on DBE-1. TIME 100 3 1100 %FD 3mm tsys are high. This may be due to a low reference 7.5 voltage. (C138224) 1104-1110 *PT has TimestampSyncError alert on DBE-1. TIME 100 6 1345 New operator is Alan Kerr 1935-1937 *MK autostow. no obvious reason. repointed. COM 100 2 0000 Date is 2016MAY23/144. 0021-0046 %MK raining. 0139 New operator is Betty Ragan. 0151-0155 *File ended on the control computer at all sites SCH 900 36 except MK, to make time for test file T161C. 0155 End. Downtime Summary: Total downtime : 225 min Percentage downtime of observing: 1.2% Average downtime per hour : 0.7 min Total scheduled observing time (# Antennas): 19544 min (8)