Summary of the GMVA Session, Apr. 22-27, 2021 ================================================ Stations participating: Europe: Ef, On, Mh, Pv, Noema_phased, GLT, (Ys for few hours) US: 8xVLBA at 3mm, 10xVLBA at 7mm GBT KVN: all 3 stations ALMA: for mk013b, mg006b, c211d =============================================================================================== European Fringetest: f211a - good fringes found for Ef, On, Mh, Pv, Noema cross hand SNR is a bit high for Mh fringes to NOEMA are particularly strong Details here: https://deki.mpifr-bonn.mpg.de/GMVA/GMVA_correlations/2021_Apr_(c211)/F211A =============================================================================================== Overall Summary: expected good performance and good weather for Eb, On, phased Noema. Mh+PV affected by bad weather. Ys could participate in only few scans. VLBA affected by bad 3mm receiver performance at several sites (FD, LA). GLT observed and was partly affected bu snow-storms. GLT observed. ALMA observed. KVN observed. After correlation: ALMA has a 3 MHz LO offset !! =============================================================================================== Station Details: Effelsberg: observing mostly under clear sky conditions, during day time stronger variations of focus and pointing. At some times the z-focus was not optimal. As usual the Tsys in channel 2 (RCP) was higher than in channel 1 (LCP). Apr22: clear sky, sunny 20h00: Tsys~200K@elv=20 Apr23: good Apr24: 16h00 sunny, cirrus clouds, Tsys=180K@elv=45 Apr25: 20h00 clear, tsys=160K@elv=59 Apr26: 01h0 UT c211c started, clear sky, c211d started on time, clear sky Apr27: clear sky, finsihed without known problems Onsala: At Onsala, the GMVA session 1/2021 went flawlessly. The 4mm receiver was used again. The pointing model was updated and checked before the session. High-SNR fringes to Onsala were found during the FTP fringe tests. The entire session was operated by me remotely. The weather was wonderful. I believe that we got a clean sky for >90% time of the session. The Tsys* data looked quite good. Onsala usually had a Tsys* of ~200 K. There was no data points of Tsys* >1000 K. This could not be better. Apr22: clear sky, tsys~200K @ elv=20 Apr23: Apr24: Apr25: Apr26: 11h52 UT blue sky for 90% of time during past weekend Apr27: Metsahovi: - Mh participated to all scheduled observations (f211a, c211a-d, mk013b and mg006b). - Not any known problems. - Unfortunately, the weather was awful (rain/wet snow/heavy clouds) most of the time, expect during the fringe test (f211a) and first half of c211a. Apr22: weather good, 20h some clouds Apr23: 09h20 blue sky, 11h05 rain Apr24: 19h00 c211b started, heavy rain Apr25: mg006b started, rainy Apr26: 01h00 UT c211c started, bad weather, 01h00 UT c211d started, cloudy Apr27: Pico Veleta: Unfortunately the weather has been very variable, and mostly poor or bad during the session. For the different schedules where Pv participated: f211a - Done 70% under poor weather mk013b - Done 100% under average/good weather c211a - Done 40% under poor weather c211b - Done last 13% under poor weather mg006b - Done 52% under poor weather c211c - Lost 100% due to bad weather c211d - Lost 100% due to bad weather Apr22: 14h00, not obs. poor weather, 17h00 weather improved Apr23: 18h30 c211a started, foggy, 21h30 Tsys~200K, wind increases Apr24: 00h40 UT stopped due to bad weather, 22h00 not obs, bad weather Apr25: 04h00 UT Pico joined c211b, Tsys~200K, pwv~11mm; start mg006b, Tsys~400K@elv=13deg, 23h34 stopped - bad weather Apr26: 01h00 UT c211c started, poor weather, 6h40 UT better, Tsys~130K, pvw=10mm, 11h40 UT stopped bad weather, Apr27: NOEMA: Apr22: 14h00 weather good Apr23: 18h30 c211a started, light clouds, Tsys~85 K, phasing_eff p=0.98, Apr24: computer crashed, 2hrs lost, 06h00 UT back observing, NGC315 is in sun-avoidance, 18h12 c211b started, Tsys~90K, Apr25: 15h18 joined mg006b, Tsys~130K, p=0.9, 21h00 thick clouds, pwv=35mm, Tsys~250K@elv=63, 21h25 UT stopped - rain Apr26: 01h00 UT c211c started, thick clouds Tsys~400K, 07h15 UT Tsys~450K, 3C84 in sun-avoidance, 18h30 UT resume on 3C84 after sunset Apr27: not participating c211d ALMA: Apr23: ALMA dropped the 0540UT scan. Apr25: ALMA starts mg006b late at 21h00 UT Apr26: ALMA starts c211d on time, weather is fine GLT: Apr22: not obs, storm, 22h50 high wind, not obs. Apr23: 00h34 GLT start obs., 10h40 tau=0.1@86GHz Apr24: 04h10 GLT starts c211a, Tsys~300K @elv=15, tau=0.1 Apr25: start mg006b, Tsys~300K@elv=15, tau=0.12 Apr26: Apr27: past day was good, 01h00 UT finish c211d as planned GBT: At GBT, we had very bad weather during mk013b, and c211a was a day-time run. Keeping the narrow beam at W-band of the GBT pointed was a challenge due to these factors. Often, we had to take manual control for that, resulting in a few missed on-target scans. c211a: 1350-1413 *GB apparently had not been on source KVN: KVN participated in 4 experiments c211a, c211c, mg006b and mk013b. There was no serious problem except bad weather during some time range. VLBA: all antennas observed, main issues are mk013b: *FD 3mm LCP bad. c211a: *FD bad 3mm LCP Tsys *PT bad 3mm LCP Tsys *LA 3mm warmed suddenly c211b: 1823-2020 *LA 3mm warm 1823-2020 *FD 3mm LCP bad 1933-2020 *PT 3mm LCP bad 1956-2020 *LA removed for 3mm work mg006b: %NL,BR rain c211c: *LA 3mm receiver warm c211d: *LA 3mm receiver warm %MK overcast/precipitation =============================================================================================== and more details for the VLBA here: mk013b: VERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- Project: MK013B Observer: Krichbaum, T. Project type: VLBI Obs filename: mk013b.vex Date/Day: 2021APR22/112 Ants Scheduled: NL FD LA PT KP OV BR MK GB =UT-Time===Comment===============================================MF#===%AD==AMD= 2230 GB begins 2353 VLBA sites (except MK) join 2353-1100 *FD 3mm LCP bad. (WO-9818) FE 25 166 0000 Date is 2021APR23/113. 0045-0054 *FD recording speed at 50%, looks like DBE1 REC 100 9 may have crashed. Rebooting DBE. 0313 MK joins 0314-0316 *PT autostowed, power glitch? COM 100 2 0550 New operator is Betty Ragan. 0830 End at GB. 1100 End. Downtime Summary: Total downtime : 177 min Percentage downtime of observing: 3.0% Average downtime per hour : 1.8 min Total scheduled observing time (# Antennas): 6000 min (8) c121a: VERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- Project: C211A Observer: Krichbaum, T. Project type: VLBI Obs filename: c211a.vex Date/Day: 2021APR23/113 Ants Scheduled: SC HN NL FD LA PT KP OV BR MK GB =UT-Time===Comment===============================================MF#===%AD==AMD= Operator is Betty Ragan 1350 Begin at GB. 1353 Begin at NL 1355 New operator: Jessica King 1350-1413 *GB apparently had not been on source. See GB log for details. 1440 FD begin. 1440-1825 *FD bad 3mm LCP Tsys. WO-9818 FE 25 416 1453 LA,PT begin. 1453-1825 *PT bad 3mm LCP Tsys. WO-9414 FE 25 413 1500 SC,HN begin. 1509 BR,OV begin. 1511 KP begin. 1639 LA erroneous rain latch. 1822-1936 *SC,PT,MK out for daily USNO. SCH 300 222 1855 New operator is Jim Ogle. 1925 MK reports clear skies. 1959 Returning operator: Jessica King 2028 %PT high winds. 2031 %FD high winds. 2038-2040 *FD wind stowed. Repointed. WEA 100 2 2136 New Operator: Paul Padilla 2151 End at GB 2312-2314 *FD autostowed, power glitch? COM 100 2 0000 Date is 2021APR24/114. 0545 New operator is Betty Ragan 0615-0628 *BR record rate is half what it should be. REC 100 13 DBE-1 is not communicating with the GUI or the device browswer, although I can ping it, and there are no alerts on it. Rebooting it. 0738-0837 *MK removed to observe Q2114. SCH 100 59 0931-0933 *SC autostowed. Power glitch? COM 100 2 1151 %BR raining. 1239-1245 *OV FRM errors. Not in correct focus FRM 100 6 position. 1350 Operator: Jessica King 1400-1825 *LA 3mm warmed suddenly. WO-9950 CRYO 50 132 1439-1440 *SC autostowed, most likely power glitch. Repointed. COM 100 1 1553-1555 *KP autostowed, power glitch. COM 100 2 1758-1810 *LA removed for site tech to work on the 3mm. CRYO 100 12 1822-1825 *SC,PT,MK out for daily USNO. SCH 300 9 1825 End. Downtime Summary: Total downtime : 1291 min Percentage downtime of observing: 7.5% Average downtime per hour : 4.5 min Total scheduled observing time (# Antennas): 17150 min (10) c211b: VERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- Project: C211B Observer: Krichbaum, T. Project type: VLBI Obs filename: c211b.vex Date/Day: 2021APR24/114 Ants Scheduled: SC HN NL FD LA PT KP OV BR MK =UT-Time===Comment===============================================MF#===%AD==AMD= Operator: Jessica King 1823 FD,KP,LA,NL,PT begin. 1823-2020 *LA 3mm warm. WO-9950 CRYO 50 778 1823-2020 *FD 3mm LCP bad. WO-9818 FE 25 389 1823-1933 *PT out for daily USNO. SCH 100 70 1824 BR,OV begin. 1824 %BR rain. 1829 SC,HN begin. 1829-1933 *SC out for daily USNO. SCH 100 64 1933-2020 *PT 3mm LCP bad. WO-9414 FE 25 371 1956-2020 *LA removed for 3mm work. CRYO 100 24 1956 MK begin. 0000 Date is 2021APR25/115. 0200 New operator is Carolyn Morris 0722-0831 *MK out for USNO SCH 100 69 1325 End at SC,HN 1350 Operator: Jessica King 1821-1840 *PT,MK out for daily USNO. SCH 200 38 1822 %NL precipitation. 2020 End. Downtime Summary: Total downtime : 1803 min Percentage downtime of observing: 11.6% Average downtime per hour : 6.9 min Total scheduled observing time (# Antennas): 15570 min (10) mg006b: VERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- Project: MG006B Observer: Krichbaum, T. Project type: VLBI Obs filename: mg006b.vex Date/Day: 2021APR25/115 Ants Scheduled: NL FD LA PT KP OV BR MK =UT-Time===Comment===============================================MF#===%AD==AMD= Operator: Jessica King 2023 Begin, all but MK. 2023-0749 *FD 3mm LCP bad Tsys WO-9818 FE 25 171 2023-0749 *LA 3mm warm WO-9950 CRYO 50 343 2023-0749 *PT 3mm LCP bad Tsys WO-9414 FE 25 171 2023 %NL,BR rain. 2308 MK begin. 0000 Date is 2021APR26/116. 0200 New operator is Carolyn Morris 0530-0532 *KP wind stow WEA 100 2 0749 End. Downtime Summary: Total downtime : 687 min Percentage downtime of observing: 12.5% Average downtime per hour : 7.5 min Total scheduled observing time (# Antennas): 5488 min (8) c211c: VERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- Project: C211C Observer: Krichbaum, T. Project type: VLBI Obs filename: c211c.vex Date/Day: 2021APR26/116 Ants Scheduled: NL FD LA PT KP OV BR MK =UT-Time===Comment===============================================MF#===%AD==AMD= Operator: Carolyn Morris 0753 Begin. 0753-0052 *LA 3mm receiver warm WO-9950 CRYO 50 509 0753-0052 *FD 3mm LCP bad Tsys WO-9818 FE 25 254 0753-0052 *PT 3mm LCP bad Tsys WO-9414 FE 25 254 1109-1110 *KP wind stow WEA 100 1 1112-1113 *KP wind stow WEA 100 1 1201-1202 *KP wind stow WEA 100 1 1204-1225 *KP wind stow, left in standby for a while WEA 100 21 1345 New operator is Jim Ogle. 1354 %Still windy at KP, gusting up to 39 MPH. 1416 FD reports scattered clouds, dry conditions. 1446 OV reports cloudy but dry conditions. 1508 LA reports clear skies. 1521 KP reports broken high clouds. 1533 PT reports clear skies. 1547-1601 LA out for AZ idler wheel inspection WO-9892 AMECH 100 14 1614 %LA FRM both drives went into lockout. It appears to FRM be in the correct position though. 1619-1624 *Parking LA so site tech can investigate FRM. FRM 100 5 1624 %LA FRM cleared on its own, back in point mode. 1821-1937 *PT and MK dropping out to run daily USNO project. SCH 200 152 1829 MK reports overcast skies. 2058 %PT very briefly indicated antenna had gone into Manual mode, then went back into Point mode. 2150 New operator is Alan Kerr 0000 Date is 2021APR27/117. 0052 End at VLBA (some non-VLBA sites continue) 0052 End. Downtime Summary: Total downtime : 1212 min Percentage downtime of observing: 14.9% Average downtime per hour : 8.9 min Total scheduled observing time (# Antennas): 8152 min (8) c211d: VERY LONG BASELINE ARRAY OBSERVING LOG -------------------------------------- Project: C211D Observer: Krichbaum, T. Project type: VLBI Obs filename: c211d.vex Date/Day: 2021APR27/117 Ants Scheduled: NL FD LA PT KP OV BR MK =UT-Time===Comment===============================================MF#===%AD==AMD= Operator is Alan Kerr 0054 Begin (at VLBA sites) 0054-0330 *LA 3mm warm WO-9950 CRYO 50 78 0054-0330 *FD 3mm LCP bad Tsys WO-9818 FE 25 39 0054-0330 *PT 3mm LCP bad Tsys WO-9414 FE 25 39 0054-0330 %MK overcast/precipitation 0330 End. Downtime Summary: Total downtime : 156 min Percentage downtime of observing: 12.5% Average downtime per hour : 7.5 min Total scheduled observing time (# Antennas): 1248 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.