Summary of the 3mm GMVA Session Oct 8-11, 2010 ----------------------------------------------- In this session the following stations participated: Eb, On, Mh, PV, PB, 8xVLBA The session was affected by relatively bad weather at Pico Veleta. Pico Veleta has lost more than half of the session. At Effelsberg the weather was clear, and for the 1st half of the seasion reasonably good at PdB. During the 2nd half of the session the weather at PdB degraded. No major problems at PdB, most scans observed. At Metsahovi the receiver broke on the first day 281, in the evening. They recorded only about 10hrs of data. The weather conditions at the VLBA were mostly good, except for BR with some rain and later scattered clouds. More detailed log information: ------------------------------ Effelsberg: ----------- Effelsberg uses a new driving program and new software for the online data reduction. The latter is used to apply the pointing corrections. The new system was installed in summer and is still in test mode. Both systems already work but need further optimization. The slew times for Effelsberg are at the moment larger than in previous 3mm GMVA sessions, allowing to do not more than one pointing between VLBI scans (previously 2 pointings were possible in 7-8 min gaps). The telescope driving sometimes behaved unexpectedly, causing either late VLBI start or loss of VLBI scans. The online pointing display sometimes gave divergent solutions for the pointing offsets, leaving uncertainty about the correct value of the pointing correction. The same applied for the focus adjustments. In contrast to earlier sessions, the focus displacement as function of outside temperature now has a positive gradient of about 0.4 mm/degree. day 281, Oct. 8, 8h30 UT : 45 min late start, powersupply in receiver repaired Tsys 240-250 K day 282, Oct. 9, 8h00 UT: clear sky blind pointing, no bright source nearby, probably no good data 18h30 UT: clear, pointing on 3C345, 3C454.3 ok day 283, Oct. 10, 9h00 UT: clear sky, the last night was very good after sunrise large variations in pointing and focus lost many scans to recover telescope pointing 12h00 UT: too much sun, pointing problems after 12 UT pointing is ok 21h00 UT: clear sky, all good, Tsys 190 K day 284, Oct. 11, 05h00 UT: a perfect clear night 10h00 UT: no good data from sun-rise to noon large variations in pointing and focus 14h00 UT: EB clear, pointing ok Pico Veleta: ------------ day 281, Oct. 8, 11h00 UT: strong wind, no observation before 11UT after 11 UT ok, some clouds, Trec=39,37K Tsys=110K 19h15 UT: stop, strong wind day 282, Oct. 9, 08h00 UT: stop, strong wind day 283, Oct. 10, 19h00 UT: restart, weather improved, Tsys=120K day 284, Oct. 11, 00h00 UT: observing, Tsys=115K, tau=0.085 11h30 UT: stop, bad weather 17h30 UT: resume observing until end Plateau de Bure: --------------- day 281, Oct. 8, 08h00 UT: start in time, all systems working overcast, Tsys ~ 110 K humidity 60%, phases stable day 282, Oct. 9, 08h00 UT: ok, observing, Tsys 120 K day 283, Oct. 10, 07h00 UT: fog, Tsys 200K 15h00 UT: Problem MK5A, 8pack changed, 1 hr lost 21h00 UT: ok, observing day 284, Oct. 11, 00h00 UT: correlator crash 10h00 UT: covered sky, light snow, Tsys 350K snow stop until 13h00 UT 13h15 UT: resume, 30mm water 17h00 UT: weather not good but observing Metsahovi: ---------- day 281, Oct. 8, 08h00 UT: Metsahovi started on time with c102a, the weather is cloudy but not terrible, Tsys estimate in the range 158K, Trec maybe around 92K day 284, Oct. 11, 13h00 UT: The receiver dewar leaked on Fri at about UT 18, meaning that we probably managed to only record UT 8-18 on Friday only. Onsala: ------- no detailed information, they were observing VERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- no known major problems, nor done time Project: C102A Observer: Krichbaum, T. Project type: OTHER Obs filename: c102acrd.* Date/Day: 2010OCT08/281 Ants Scheduled: NL FD LA PT KP OV BR MK =UT-Time===Comment===============================================MF#===%AD==AMD= Operator is Alan Kerr GPS delta, vclock: OK, UT1-UTC: -0.07 0756 Begin (except MK) 0815-0845 *FD MK5 communication lost. bank read error. 27695 100 30 0827 MK begins 0900-1014 *FD MK5 not recording. keeps switching between IDLE 27695 100 74 and trying to record but failing. 0906 *FD MK5 bank B, UAO-0102, 55.97/4000.77 written has marked itself as FULL. Site Tech called out. 1338 New Operator: Paul Padilla 1358 %LA WEA: Broken clouds, light rain. 1405: %BR WEA: Low overcast cloud cover 1625-1628 *BR Mark5 communications lost. Addictionally, a non- REC 100 3 specific doComent() error occurred, and Mark5 went into an OFFLINE state. Attempting to online made it cycle between OFFLINE, IDLE, and MOUNTED for a few moments. Fortunately, it appears this occurred during a non-recording scan. 1630 BR continued to record normally once a recording scan began. 2142 Operator is A. Sowinski. 0000 Date is 2010OCT09/282. 0031-0033 *PT HC2 formatter errors. 21522 100 2 0535-0538 *PT Autostow, repointed. COM 100 3 0545 New Operator is Alan Kerr 1027-1209 %BR precipitation 1351 New operator is Jim Ogle. 1405-1406 *BR Mark5 comm loss. No error message received and REC 100 1 it came back up on its own. 1413 %MK 3mm is running a bit warm on the 15K stage but is CRYO fine on the 50K stage. 1426-1427 *PT autostowed. Power glitch? Repointed. COM 100 1 1539-1540 *KP autostowed, power glitch. Repointed. COM 100 1 1641 %BR Mark5 comm lost again, but only for about 20 seconds before coming back on its own. May be more of a networking issue than a Mark5 problem. 2124 *Raining at BR. 2045 %FD 3mm is running a bit on the warm side. 0000 Date is 2010OCT10/283. 0144 New operator is Betty Ragan. 0144 %BR Mark 5 communications lost very briefly again. 0421 %BR Mark 5 lost comms for a few seconds again. 0447 %BR MK5 communications loss again. 0909 %MK windy. 1006 %BR MK5 communication loss again. 1244-1245 *PT HC2 FIFO error. FMTR 100 1 1311 %BR Mark 5 comms lost for a few seconds again. 1326 New operator: T. Perreault 1342 %BR Mark5 communications loss 1425 %BR Mark5 communications loss 1604 %BR Mark5 communications loss 1718 %BR Mark5 communications loss 1759 BR wea: raining 1933 %BR Mark5 communications loss 2126 %BR Mark5 communications loss 2218-2229 KP loss of internet communication 0000 Date is 2010OCT11/284. 0136 New operator is Betty Ragan. 0435 %BR Mark 5 communications loss. 0441 %BR Mark 5 communications loss. 0635 %BR Mark 5 communications loss. 0853 %BR Mark 5 communications loss. 1332 New operator: T. Perreault 1332 LA wea: clear, no precipitation 1405 %BR Mark 5 communications loss 1408 BR wea: few high scattered clouds, no precipitation 1419-1423 *PT Formatter error 21522 100 4 HC2 FIFO error Backplane 1PPS Marker Detected FIFO 3 1PPS detected FIFO 2 1PPS detected FIFO 1 1PPS detected Cleared at source change 1453 OV wea: clear, no precipitation 1520-1522 *PT autostowed. Power glitch. Repointed. COM 100 2 1522 KP wea: clear, no precipitation 1528 %BR Mark5 communication loss 1612 %KP Mark5 communication loss 1620 %BR Mark5 communication loss 1722-1727 *KP observing system appears to have hung. A reobs SW 100 5 didn't work, rebooting VME. 1745-1751 *LA rotation drive fault. FRM 100 6 1819 %BR Mark5 communication loss 1914 MK wea: clear, windy, no precipitation 2122 %BR Mark5 communication loss 2133 New Operator: Paul Padilla 2208-2211 *PT autostowed, power glitch COM 100 3 2227 End. Downtime Summary: Total downtime : 136 min Percentage downtime of observing: 0.3% Average downtime per hour : 0.2 min Total scheduled observing time (# Antennas): 41528 min (8) Notes: * = Entries where data was affected. % = Entries where data may have been affected. & = Entries where the site tech was called out. WEA = Weather entries. MF# = Maintenance form or major downtime category associated with a problem. %AD = The percentage of an antenna affected by a problem. AMD = Total antenna-minutes downtime for a problem. Tsys = System Temperature (TP/SP x Tcal/2) ACU = Antenna Control Unit FRM = Focus/Rotation Mount RFI = Radio Frequency Interference VME = Site control computer CB = Circuit Breaker vclock = Program that compares site clock time to a standard.