Recent developments/improvements for GMVA ============================================= last update: 10.05.2023 May. 2023 : GMVA session completed, additional stations which joined: Atca, Mopra, JCMT, LMT, (and Haystack for test). Jan. 2023 : For ALMA proposal cycle 10, 7mm observations with a subset of GMVA stations is offered, which include the VLBA, the GBT, Effelsberg, Onsala, Metsahovi, Yebes and the KVN. IRAM is not available at 43 GHz. Dec. 2022 : IRAM 30m telescope maintenance between May - October/November 2023. Telescope not available during this time. Oct. 2022 : New proposal call for Large Millimeter Telescope (LMT) for Session 2023-S1: Jan. 2 - June 30, 2023. Deadline: Oct. 22, 2022, 05h00 UTC. More information here: http://lmtgtm.org/for-lmt-users/call-for-proposals/ Mar. 2022 : several new stations will join the session April 2022 on a best effort basis: Haystack, MOPRA, ATCA. ATCA can do only 1 Gbps, MOPRA uses OCTAD backend and KVN style setup (4 Gbps). Aug. 2021 : VLBA Test Memo 73 released, describing pointing and focus issues at high frequencies (https://library.nrao.edu/vlbat.shtml) July 2021 : GMVA Proposal call for Aug.2, 2021 for observations in Spring 2022 and later; NOEMA participates as phased array. For details see: https://science.nrao.edu/observing/call-for-proposals/2022a Feb. 2021 : ALMA Cycle 8 2021 Pre-Announcement, proposal deadline April 21, 2021; see: https://almascience.nrao.edu/news/alma-cycle-8-2021-pre-announcement Jan. 2021 : GMVA and GMVA+ALMA (Cycle 8) proposal call issued, deadline Feb. 1st, 2021. See https://science.nrao.edu/observing/call-for-proposals/2021b/vlba-proposal-guide. Dec. 2020 : LMT proposal call open for 3mm VLBI, please resubmit your proposal until Dec. 21, 2020. (http://lmtgtm.org/proposal-submission-process) Dec. 2020 : Dec. 10; first fringes at 86 GHz with phased Noema (Ys-No, 3C454.3, SNR ~ 300). Oct. 2020 : GMVA observations at 88 GHz sucessfully tested (f202a, c202c, LO=87300 MHz). Switching from one LO setting to the other can be done within 30mins. Apr. 2020 : VLBA pointing issue, which was affecting previous sessions is most likely fixed Mar. 2020 : Due to Corona virus pandemic disease, ALMA and GLT will not be able to observe in April 2020. Proposal call for ALMA Cycle 8 has been issued, this will be for GMVA+ALMA observations in 2021. Jan. 2020 : Proposal call for GMVA and GMVA+ALMA issued. The previous flux limit for ALMA is dropped and phase transfer from a brighter calibrator (S > 500 mJy) to a fainter target is now possible (passive phasing). The phasing calibrator should be within 5 deg of the science target. Dec. 2019 : VLBA changed to new antenna control system. Unfortunately this affected the GMVA session in Oct. 2019 quite badly. Aug. 2019 : after successful 4Gbps fringe tests in April, the GMVA now switches to 4 Gbps using a tunable DDC mode with 8x128 MHz at the VLBA and 16x64 MHz in Europe. The DDC mode should also re-enable SiO maser pointing at the VLBA, which wasn't working with the PFB mode. GLT confirmed GMVA participation for Autumn 2019/Spring 2020. No participation of NOEMA and LMT in Oct. 2019 (technical not ready). Mar. 2019 : Yebes has a new 3mm receiver, now with dual polarisation. Fringes on PV-Ys baseline look very good. Feb. 2019 : VLBA in transition to a new control system. Technical issues unfortunately affect the data. SiO line pointing not available in PFB mode. Jan. 2019 : LMT agreeed to participate in GMVA observations for 2020, PIs are asked to contact the observatory for local collaborators from the LMT and its partner institutions (Mexican and UMASS scientists). LMT time allocation depends also on an internal LMT review. Nov. 2018 : Proposal deadline for GMVA+ALMA (Cycle 7, spring 2020) due Feb. 1st, 2019 July 2018 : strong fringes of GLT to all GMVA stations seen, note that GLT recorded at 16 GBps using Mark6. To match the lower bandwidth of the GMVA the data are correlated with the DifX Zoom mode. Participation of the GLT in future GMVA runs is being discussed. Apr. 2018 : The Greenland Telescope (GLT), presently located in Thule, participated for the first time in a GMVA session (c181, on a best effort basis). Feb. 2018 : Installation of a new H-maser at Pico Veleta, data acquisition from now on using Fila10G, Mark6 recorders and DBBC2 Feb. 2018 : Proposals due for GMVA+Alma Cycle 6; guidelines here: https://www.astro.uni-bonn.de/ARC/development/mmvlbi/guidelines.shtml, and here: https://almascience.eso.org/news/announcement-for-3mm-vlbi-in-cycle-5 Jan. 2018 : Proposals asking for 3mm VLBI with ALMA in Cycle 6 (2018/2019), have to be submitted to the GMVA by Feb. 1st, 2018 and must be also submitted to ALMA by April 19, 2018. Due to reconstruction PdB is not available in 2018. Dec. 2017 : Further improved version of PolConvert, which is the software to transform the two linear polarizations from ALMA into dual circular. May 2017 : GMVA observations with ALMA went well, strong fringes, good phasing stability. Dec. 2016 : Proposals asking for 3mm VLBI with ALMA in Cycle 5 (2017/2018), have to be submitted to the GMVA by Feb. 1st, 2017 and must be also submitted to ALMA by April 20, 2017. The GMVA sensitivity calculator has been updated. Due to reconstruction PdB is not available in 2017. Sep. 2016 : Haystack's 37m dish joins for a first 3mm fringe test (w. linear feeds); a test experiment with VLBA and ATCA was performed. ATCA is limited to 1 Gbps and 2 IFs, each of 64 MHz bandwidth, ATCA supports only linear feeds. Jan. 2016 : GMVA proposal call now also including KVN and ALMA. LMT could participate on a best effort basis, but needs local collaborators. Initital GMVA observations with ALMA are planned for Spring 2017. 3mm VLBI with the phased ALMA is presently limited to sources with flux of at least 500 mJy. ALMA37 is now included in the EVN sensitivity calculator. Dec. 2015 : ALMA issued a VLBI proposal pre-anouncement, ALMA+GMVA VLBI observations could be proposed via the normal GMVA proposal chain, proposal deadline is February 1st, 2016. The same proposal has to be submited to ALMA for the AO4 deadline in April 2016. Earliest 3mm VLBI observations with ALMA could happen in Spring 2017. Nov. 2015 : update GMVA sensitivity page, include KVN, and preliminary values for LMT and ALMA. Oct 2015 : KVN wants to join the GMVA for the Feb. 2016 proposal deadline. Sep 2015 : Metsahovi has a new 3mm receiver. Aug 2015 : First fringes between ALMA and VLBA at 86 GHz (ALMA Band 3) (bm434 test on Aug. 1-3, 4 IFs, each 128 MHz wide, DifX zoom mode) June 2015 : Participation of the LMT at 86 GHz on a best effort basis in 2016. Full participation of GBT, but must be justified in proposal. Metsahovi may join in at 43 GHz, the 86 GHz receiver is not working. 43 GHz VLBI in gaps is possible with: KVN, Noto, Metsahovi, VLBA May 2015 : Onsala uses its new dual polarisation receiver, which now works. GBT and KVN join the May session. April 2015 : 1 Gbit/s tunable mode tested for Effelsberg, Yebes and Onsala. Fringes ok. Sep 2014 : add KVN test at 1 GBps, but now using 32 MHz wide IFs in LSB&USB for better compability The GBT joined part of the Sep. 2014 GMVA session. July 2014 : improvement of DiFX2fits, zoom mode for PdB now works and AIPS can deal with it May 2014 : new dual polarization receiver at Onsala, but unfortunately only erratic fringes yet Feb 2014 : 2 Gbps recording VLBA+PV+EB+GBT works, some disk performance issues at VLBA Jan 2014 : 7mm RDBE/DBBC fringes between Noto and VLBA at 2 Gbps (Noto joined interleaved 7mm scans) July 2013 : Sensitivity Matrix on GMVA webpage updated. Include GBT, Yebes, KVN. July 2013 : GMVA proposals should now be submitted via the NRAO Proposal Tool (proposals prepared with the old latex style files are no more accepted). May 2013 : Observation in Autumn 2013 will use the PFB at 2 Gbit/s Feb. 2013 : Fringe test using DBBC_PFB and RDBE_PFB at 2 Gbit/s Polyphase filter bank tested in Europe 3mm fringes at 2 Gbps between VLBA and GBT established August 2012 : Meeting of GMVA directors in Bonn July 2012 : Consider 2 Gbps recording for 2013, GBT may become available 2nd half 2013 June 2012 : Fringes to all 3 Korean VLBI stations found with PdB (SNR ~ 10-20 on a 1 Jy source) KVN wants both sidebands (LSB+USB) May 2012 : Fringe test with Korean VLBI Network (KVN) planned, MK5B format November 2011 : Digital VLBI Backend (DBBC) installed at Pico Veleta Digital VLBI Backend (DBBC) installed at Effelsberg October 2011: : Yebes participated sucessfully in October session May 2011 : First 3mm fringes to Yebes 40m antenna found, SNR=600 (PdB-Yb), SNR=400 (PV-Yb) October 2009 : Correlation using DiFX correlator (Oct. 2009 session) April 2009 : improved performance at PV, new EMIR receiver April 2008 : improved performance at PdB, new SIS receivers, world-record SNR=5423 for 3C454.3 on PV-PdB baseline May 2007 : parallel observing at 7mm and/or 13mm with VLBA during European pointing gaps now possible May 2006 : 1 Gbps recording possible in Europe (EB, PV, PdB, ON, MH)