Summary of the GMVA Session, Oct 8-12, 2020 ================================================ Stations participating: Europe: Ef, On, Mh, Ys, Pv US: 8xVLBA at 3mm, 10xVLBA at 7mm PT has problems at may not deliver usefull data HN out. AZ wheel damage, resumed in C202B. LA,MK removed for daily USNO observation OV stowed for repair of 7mm receiver (affects most of C202B) KVN: all ============================================================================================================ European Fringetest: f202a: 86 GHz fringes found to all Stations, except PV (formatter time offset) good fringes to Ef-PV seen later in c202a 88 GHz fringes found on Ef-On, Ef-Mh no fringes to Ys (yet) no fringes to Pv (yet) Details here: https://deki.mpifr-bonn.mpg.de/GMVA/GMVA_correlations/2020_Oct_(c202)/F202A =============================================================================================================== Station Details Effelsberg: observing under quite bad weather, wind, rain, clouds. In the pointing scans we realize strong oscillations in the elevation direction, in azimut direction the pointing scans look ok. As a consequence the pointing accuarcy is reduced in the whole session. Oct 8 rain +thick clouds Oct 9 bad weather during day, better in evening Oct 10 EB many clouds, quite frequent loss of IF power when changing between pointing and vlbi mode Oct 11 cloudy, instable weather, Tsys ~ 200K Oct 12 changed to 88 GHz, 00h15 cloudy, Tsys 210K, 03h00 UT ptg may be off by half a beam? Pico Veleta: Oct 9 12h30 Tsys about 160K and tau@3mm 0.1, cloudy Oct 10 10h44 good, Tsys~160K tau=0.1 Oct 11 thick clouds The session went well with some periods of anomalous refraction in the atmosphere. 89.9% of the scans were recorded. The initial fringe test did not result in fringes to PV due to technical issues. The problem was tracked down by Salvador to the GPS synchronisation module of the FILA10G, and was solved before the start of the first science schedule c192a (fringes were confirmed to PV on the first scans of c192a). Yebes: Oct 8 quarter wave plate problem fixed Oct 9 05h19 clear and calm Oct 10 11h23 good, clear sky, light wind Oct 11 clear, Tsys ~ 120K Metsahovi: The weather conditions weren't so favorable during the session. The sky was cloudy for the most part of time, and some rain showers occasionally. LO change between 86 and 88 GHz completed without known problem. Oct 8 23h30 UT rain Oct 9 0h00 UT cloudy Oct 12 Some clouds Onsala: using 4mm receiver and a tuneable LO. The 3mm receiver, dedicated to the GMVA sessions and providing more stable phase with a fixed-frequency LO, was unfortunately broken just a few days before the session. The first two experiments C202A and C202B went smoothly. However, the auto-tuning system somehow failed at the beginning of the last experiment C202C. The problem was found in the early morning and solved at 3:08 UT. So, the fringes might pop up only in the last four hours. The weather was poor. Most of time, it was cloudy and raining. KVN: KVN participated in c202a and c202b. c202a: no problem c202b: Ku delayed start by 1hr due to technical problem It is likely that the polarisation was swapped at all KVM stations. VLBA: VERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- Project: C202A Observer: Krichbaum, T. Project type: VLBI Obs filename: c202a.vex Date/Day: 2020OCT08/282 Ants Scheduled: SC HN NL FD LA PT KP OV BR MK =UT-Time===Comment===============================================MF#===%AD==AMD= Operator is Paul Padilla 1753 Begin at all VLBA sites except SC and HN 1753-0100 *OV 7mm cryo is warm CRYO 50 213 1753-1831 *LA,MK out for daily USNO observation SCH 200 76 1753-0053 %PT Tsys are garbage due to an unknown reason OTHER 1820-1838 *OV stowed so Site Tech can get on antenna CRYO 100 18 1913-0053 %PT DBE1 unresponsive, may be communications COMM issue caused by a download for a fringeCheck. 1922-2015 *PT Mark6 seems to have crashed, rebooting REC 100 53 1959 PT Mark6 expansion isn't coming back up. Site Tech returning to site to manually power-cycle the unit. 2028-2130 *PT Mark6 crashed again during a fringeCheck REC 100 62 2102 PT Site Tech has turned the expansion chassis back on, but it is still not recording. 2130 PT Mark6 finally came back up and is recording at the proper speed. 2145 New operator is Alan Kerr 2306 Begin at SC,HN 2306-1732 *HN out. AZ wheel damage. WO-8049 AMECH 100 1106 0000 Date is 2020OCT09/283. 0555 New operator: Jessica King 0555 %SC precipitation. 1343 New Operator: Paul Padilla 1719-1731 *OV Site Tech needs to get into the Vertex Room CRYO 100 12 temporarily. 1721-1832 *LA,MK removed for daily USNO observation SCH 200 142 1832-1854 *MK DBE1 timing errors. Resynched. TIME 100 22 2145 New operator is Alan Kerr 0000 Date is 2020OCT10/284. 0053 End. Downtime Summary: Total downtime : 1704 min Percentage downtime of observing: 9.2% Average downtime per hour : 5.5 min Total scheduled observing time (# Antennas): 18600 min (10) ERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- Project: C202B Observer: Krichbaum, T. Project type: VLBI Obs filename: c202b.vex Date/Day: 2020OCT10/284 Ants Scheduled: SC HN NL FD LA PT KP OV BR MK =UT-Time===Comment===============================================MF#===%AD==AMD= Operator is Alan Kerr 0100 Begin (except at SC,HN) 0100-0325 *PT has bad/meaningless tsys. VLBASYS-854 TIME 100 3025 0104 Begin at SC,HN 0545 New operator: Jessica King 0721-0839 *MK out for USNO. SCH 100 78 0839 %MK RMDS is no longer running. Monitor data will be unavailable, but hopefully astronomical data is still good. 1110 %ALL SITES seem to be having monitor data problems now, not just MK. 1349 New operator is Carolyn Morris 1722-1831 LA,MK out for daily USNO SCH 200 69 2028-0422 *OV 7mm warming (WO-8205) CRYO 50 237 2331-2356 *KP autostow. power glitch? COM 100 25 0000 Date is 2020OCT11/285. 0154 New operator is Betty Ragan 0422-0559 *OV parked for site tech to work on 7mm cryo. CRYO 100 97 0559-1315 *OV 7mm still warm, but cooling. CRYO 50 218 1345 New operator is Carolyn Morris 1751-1902 *LA,MK out for daily USNO. SCH 200 142 1910-1923 *OV stowed for site tech to work on 7mm cryo. CRYO 100 13 1910-1912 *LA parked after USNO ended. SW 100 2 2355 End at SC,HN 0000 Date is 2020OCT12/286. 0006 %BR raining. 0101-0118 *LA report spurious personality conflicts in RDBEs, SW 100 17 restarting executor. 0148 New operator is Betty Ragan. 0325 End. Downtime Summary: Total downtime : 3923 min Percentage downtime of observing: 13.0% Average downtime per hour : 7.8 min Total scheduled observing time (# Antennas): 30250 min (10) VERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- Project: C202C Observer: Krichbaum, T. Project type: VLBI Obs filename: c202c.vex Date/Day: 2020OCT12/286 Ants Scheduled: NL FD LA PT KP OV BR MK =UT-Time===Comment===============================================MF#===%AD==AMD= Operator is Betty Ragan 0334 Begin at all sites except MK. 0334-1200 *PT has bad/meaningless tsys. Data is probably TIME 100 506 bad. (VLBASYS-854) 0334-1200 %ALL SITES are having problems sending back monitor data. 0626 Begin at MK. 1102 %NL raining 1200 End. Downtime Summary: Total downtime : 506 min Percentage downtime of observing: 12.5% Average downtime per hour : 7.5 min Total scheduled observing time (# Antennas): 4048 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.