================================================================ | INSTRUCTIONS FOR OBSERVERS USING THE EUROPEAN VLBI NETWORK | ================================================================ Last update: 10 December 2009 (R. Porcas: porcas@mpifr-bonn.mpg.de) ================== | INTRODUCTION | ================== These instructions are provided for assisting EVN observers. They are continually updated; please make sure you have the LATEST VERSION, available from: ==> http://www.mpifr-bonn.mpg.de/EVN/EVNinstructions and http://www.mpifr-bonn.mpg.de/EVN/EVNinstructions.ps ****************************************************************************** * Notification that time has been assigned to an EVN project is given by * * sending a copy of the EVN BLOCK SCHEDULE to the designated Contact Author. * * The investigators must provide a machine-readable observing schedule for * * the observations using standard scheduling software, available via WWW. * * * * IT IS MOST IMPORTANT THAT THIS BE DONE IN A TIMELY MANNER. THE * * SCHEDULE MUST BE DEPOSITED ON THE EVN CENTRAL FILE SERVER VLBEER IN * * BOLOGNA BY THE DEADLINE PRINTED AT THE BOTTOM OF THE BLOCK SCHEDULE * * * * ===> Please read through the following sections NOW: * * * * 1) CHECK THE TIME (Contact the EVN SCHEDULER if you notice any errors) * * ==> porcas@mpifr-bonn.mpg.de * * * * 2) ASSISTANCE WITH MAKING A SCHEDULE (Contact JIVE if you need help) * * ==> campbell@jive.nl * * * ****************************************************************************** Before making the schedule, read through carefully section 3) GENERAL COMMENTS and any of the following additional sections which may be relevant: 4) EVN+MERLIN OBSERVATIONS 5) GLOBAL OBSERVATIONS 6) VLBA CORRELATOR 7) SPECTRAL LINE OBSERVATIONS Some information about running the scheduling program SCHED is given in 8) VLBA/MK4 MODE SCHEDULES Instructions for putting schedules on the EVN (and VLBA) servers are given in 9) DEPOSITING SCHEDULES Some information for later stages of the project is given in: 10) AFTER DEPOSITING THE OBSERVING SCHEDULE *********************************** * * * Good Luck with your project ! * * * *********************************** ================================== | 1) CHECK THE TIME ALLOCATION | ================================== Check the entries on the current EVN BLOCK SCHEDULE for all projects for which you are the Contact Person for scheduling. In particular, check that - the UT TIME RANGE corresponds to the GST interval requested and approved by the EVNPC - the observing WAVELENGTH band is correct. (If switching between bands is required at some stations, make sure this is indicated) - the EVN STATIONS and PROCESSOR listed are correct (see list of codes in the OBSERVATORY FRIENDS table below) - the quantity of recording disk space allocated per station is correct. The Mk5A disk allocation (in T-Bytes) for EVN telescopes is calculated from the project bit-rate assuming that data will be recorded for no more than 90% of the time allocated on the schedule. If for any reason this is insufficient, contact the EVN scheduler (see below). *************************************************************************** * * * => Contact the EVN Scheduler IMMEDIATELY if there is any error * * * * ------->> porcas@mpifr-bonn.mpg.de * * * *************************************************************************** ********************************************************************* * Investigators are reminded that the participation of antennas * * other than those of the EVN, NRAO and DSN (e.g. Algonquin Park * * or Ny-Alesund) must be ARRANGED BY THE INVESTIGATORS THEMSELVES, * * even if they have included them in the EVN proposal. * * * * Investigators must secure telescope time for the UT period * * allocated by the EVN Scheduler, ensure that the observatory has * * a sufficient supply of MK5A disk packs, and that the observatory * * staff will retrieve the schedule, oversee the observing, and * * make a timely delivery of disk-packs, logs and calibration data * * to the designated correlator. Consult the document "Code of * * Practice for non-EVN Observatories" under "Scheduling EVN * * Experiments" in the EVN Users Guide. * * * * Addition of antennas NOT REQUESTED IN THE OBSERVING PROPOSAL * * must first be authorised by the EVNPC Chairman. Recordings made * * at antennas without such permission will not normally be * * correlated. * ********************************************************************* Investigators of projects using the VLBA + EFFELSBERG ONLY or the HSA + EFFELSBERG should consult the documents: ===> http://www.mpifr-bonn.mpg.de/EVN/VLBA-EB-instructions ===> http://www.mpifr-bonn.mpg.de/EVN/HSA-EB ========================================== | 2) ASSISTANCE WITH MAKING A SCHEDULE | ========================================== Observers who are USING THE EVN FOR THE FIRST TIME are strongly advised to seek assistance from an experienced user. The Joint Institute for VLBI in Europe (JIVE) can also provide support in making the observing schedule. ****************************************************************************** * * * ==> Contact Bob Campbell (campbell@jive.nl) WELL BEFORE the schedule * * deadline if you need the help of a support scientist. * * * * ==> Contact the appropriate VLBI OBSERVATORY FRIEND for specific * * questions regarding individual observatories. * * * ****************************************************************************** Further information regarding scheduling of EVN experiments can be found at: =====> http://www.evlbi.org/scheduling/scheduling.html ------------------------------------------------------------------------------ E-MAIL ADDRESSES OF OBSERVATORY FRIENDS ------------------------------------------------------------------------------ EVN User-support campbell@jive.nl B.CAMPBELL Eb Effelsberg ubach@mpifr-bonn.mpg.de U.BACH Wb Westerbork observer@astron.nl N.PRADEL (pradel@astron.nl) Jb/Cm Jodrell/Cambridge vlbi@jb.man.ac.uk A.GUNN(Alastair.Gunn@manchester.ac.uk) Mc Medicina vlbifriend@ira.inaf.it A.ORLATI (a.orlati@..) Nt Noto p.cassaro@ira.inaf.it P.CASSARO On Onsala michael.lindqvist@chalmers.se M.LINDQVIST Tr Torun kb@astro.uni.torun.pl K.BORKOWSKI Ur Nanshan (Urumqi) liux@uao.ac.cn LIU XIANG Sh Sheshan(Shanghai) bxia@shao.ac.cn BO XIA Hh Hartebeesthoek jon@hartrao.ac.za J.QUICK Ys Yebes f.colomer@oan.es F.COLOMER Mh Metsaehovi vlbi@kurp.hut.fi A.MUJUNEN (Ari.Mujunen@tkk.fi) Wz Wettzell kronschnabl@fs.wettzell.de G.KRONSCHNABL Ar Arecibo vlbi-grp@naic.edu T.GHOSH (tghosh@..) J JIVE Correlator jops@jive.nl B.CAMPBELL (campbell@) Soc VLBA Correlator analysts@nrao.edu B Bonn Correlator mk4@mpifr-bonn.mpg.de W.ALEF (alef@..) EVN Scheduler porcas@mpifr-bonn.mpg.de R.PORCAS MERLIN Scheduler merlin@jb.man.ac.uk P.THOMASSON TOG Chair alef@mpifr-bonn.mpg.de W.ALEF EVNPC Chair tventuri@ira.inaf.it T.VENTURI ------------------------------------------------------------------------------ NON-EVN (AFFILIATE) OBSERVATORIES ------------------------------------------------------------------------------ Ro Robledo CGMiro@mdscc.nasa.gov C.GARCIA-MIRO Ro/Go DSN george.martinez@dsn.nasa.gov G.MARTINEZ Ny Ny-Alesund vlbi@statkart.no ------------------------------------------------------------------------------ ============================================== | 3) GENERAL POINTS WHEN MAKING A SCHEDULE | ============================================== ********************************************************************* * SCHEDULE YOUR OBSERVATIONS: * * * * => only within the UT time slot allocated for your project * * on the EVN block schedule * * * * => only for programs requested in the observing proposal * * and approved by the EVN Program Committee * * * * => using only the recording mode requested in the proposal * * and approved by the EVN Program Committee or its Chair * * * * READ THESE INSTRUCTIONS before making the observing schedule, * * and RE-READ them afterwards. * ********************************************************************* 3.1 HOW MANY SCHEDULE FILES ? A single schedule file should be made, which includes all participating antennas, for each observation labelled with a distinct experiment code on the block schedule. In particular this applies to Global observations where antennas of both the EVN and the VLBA are observing; the scheduling program SCHED can deal with the case that not all antennas are observing for the entire observation; only a single file should be produced. If an observing project is scheduled in separate segments (e.g. if different sources are scheduled in different parts of the session or if different frequency bands are involved) the segments will have distinct experiment codes (e.g. GG053A, GG053B); in this case a separate schedule file should be produced for each segment. 3.2 ADVICE ON INCLUDING CALIBRATION SOURCES - PIs are encouraged to schedule strong, compact "FRINGE-FINDER" sources SEVERAL TIMES throughout their observing run, with scans of 10 minutes or longer. AVOID THE FIRST FEW SCANS (sometimes lost at start-up !) for these. Try to schedule them at times when the sources are visible to all antennas. (Check elevations and remember hour-angle limits at WESTERBORK !) Unless otherwise specified, data from these scans may be used by correlator staff to help monitor the performance of the array through the network sessions. Suitable sources may be found at: ====> http://www.aoc.nrao.edu/~analysts/vlba/ffs.html - To improve on the default AMPLITUDE calibration provided (see under 10.4 EVN PIPELINE below), periodic (e.g. every 20 minutes) observation of a single compact calibration source should be made. Suitable sources, which should be quasi point-like, brighter than ~200 mJy and within 5 degrees of the program source, can be selected from the VLBA calibrator survey, available interactively at: ====> http://www.vlba.nrao.edu/astro/calib/ Calibrators which are slightly resolved may also be used, provided their structures are sufficiently simple and compact to allow high-fidelity mapping using self-calibration, the solutions from which can be applied to the program source. - For POLARIZATION-sensitive VLBI observations there are two further important aspects of antenna calibration to consider: 1) calibration of the instrumental polarizations (D-terms) 2) calibration of the absolute polarization position angles (PPAs) Consult "SCHEDULING POLARIZATION EXPTS" in the EVN User Guide under: ========> http://www.evlbi.org/scheduling/evn_pol.html Suitable VLBI PPA calibrators are now regularly monitored at the VLA. Consult VLBA Scientific Memo 26 and inspect the latest monitoring results at: ===> http://www.aoc.nrao.edu/~smyers/calibration/ 3.3 INDIVIDUAL TELESCOPE FEATURES - The WESTERBORK array (WSRT) operates by default in "phased-array" mode (except at 5cm, for which only one antenna has a receiver). This mode gives an effective collecting area up to 93 m, but a primary beam of only 3 arcsec at 6 cm wavelength (size proportional to wavelength). A larger field of view can be obtained by requesting only part of the array, or just a single antenna. Contact the WSRT Observatory Friend if this option is desired. - WSRT in phased-array mode works on a 10s clock, so scans shorter than ~40s are likely to be entirely lost due to slewing and restarting the local fringe and delay for the new position. - Ensure that source coordinates are sufficiently accurate if you are using WSRT or the VLA as a phased-array. - the JODRELL BANK LOVELL Telescope ("Jb1") is restricted in the frequency of source changes to no more than 12 per hour. For phase-referencing experiments, cycle times of 10 mins can be sustained (e.g. 3m cal + 7m target). If you require faster cycle times the JODRELL MK2 telescope ("Jb2") should be used instead. - The current azimuth drive rate for the EFFELSBERG 100m telescope is restricted to 25 degrees/minute. Make sure that this value is used the scheduling program for calculating slew times. - At 6cm and shorter wavelengths the pointing of the EFFELSBERG antenna needs to be checked periodically. Leave a gap of ca. 8 minutes for this between scans every 4 hours at 6cm (more often at shorter wavelengths). - Telescopes of the NASA DSN do not take part for complete EVN sessions, and allocations of time for a project may not be for the entire time. Up to 90 minutes at the start of the notional allocated period and 30 minutes at the end may be needed for equipment set-up and changes. The time allocations indicated in the EVN BLOCK SCHEDULE for DSN antennas are the total useable time after these periods have been subtracted. - The ROBLEDO 70m subreflector can be set in a "fixed" or "tracking" mode; in the latter the subreflector is moved to a pre-determined position which optimizes the gain for each elevation. The default setting is now "tracking" (as from April 2004). Users who need to have the "fixed" setting should contact the Robledo observing friend. - The CAMBRIDGE antenna is available for 1.3cm observations, but at other wavelengths is normally available only in conjunction with MERLIN. (See section 4) - Distinguish between the different antennas at On, Jb and Ro: __________________________________________________________ SITE ANTENNA WAVELENGTHS (cm) SCHED NAME ------- ------------- ------------------ ---------- JODRELL - LOVELL (76 m) 6, 18/21, 50, 90 "JODRELL1" - MARK2 (25 m) 1.3, 5, 6, 18/21 "JODRELL2" ONSALA - 25 m (85 ft) 5, 6, 18, 21 and 30 "ONSALA85" - 20 m (60 ft) 13, 3.6, 1.3 and 0.7 "ONSALA60" ROBLEDO - DSS63 (70 m) 18, 13, 3.6, 1.3 "ROB70" - DSS65 (34 m) 13, 3.6 "ROB34" ___________________________________________________________ 3.4 MK5 DISK RECORDING ******************************************* * ALL EVN OBSERVATORIES WILL USE MK5 DISK * * RECORDING FOR EVN OBSERVING SESSIONS. * ******************************************* This move away from tape recording at EVN stations eases the task of making the observing schedule by removing any consideration of tape motion logistics at the EVN observatories. However, it is still necessary to have gaps in recording (breaks between some scans) occasionally for a number of reasons. - Most EVN observatories do not have continuous noise injection for measurement of system temperatures but, instead, rely on periodic execution of a procedure (lasting ~10 s) prior to a scan. This procedure is triggered by the SCHED program only if a sufficiently large gap in recording is scheduled before the scan. It is recommended that such a gap be scheduled at least every 15 minutes, even if the schedule continues afterwards on the same source. If the gap is scheduled between 2 different sources, then account must be taken of the telescope drive times to the new source; the gap should be at least 10s longer than this, since the telescopes should be on source when the system temperature measurement is executed. - During phase-referencing observations with rapid target/reference source change cycles it may be undesireable to execute the procedure before each scan. In this case it is sensible to schedule no gap between the rapid source changes. - Because of the need to have periodic recording gaps, the amount of recording disk space assigned to an experiment is 10% less than would be needed for recording continuously for the whole time period assigned. - For Global observations involving the NRAO VLBA, the GBT or the VLA, recording at these stations will also be made using MK5 disks. - The JIVE correlator is limited to 16 (simultaneous) stations on playback (unless multi-pass correlation is explicitly authorized by the EVN Program Committee). The VLBA correlator is limited to 17 stations on playback. ====================================== | 4) JOINT EVN-MERLIN OBSERVATIONS | ====================================== Users are advised to consult: ===> http://www.jb.man.ac.uk/merlin/evn+merlin.html The VLBI schedule will be used by MERLIN staff to create the MERLIN schedule. ===> Include both CAMBRIDGE and JODRELL telescopes in the VLBI schedule Note that the 32 MHz signal from the Cambridge telescope is used for both MERLIN and VLBI; it may be either single (LHC) polarisation or dual (16 MHz each) polarisation (as for the rest of MERLIN). As a default, the Cambridge signal will be single LHC for single-polarisation VLBI experiments, and dual polarisation for dual polarisation VLBI. ===> Contact the Jodrell VLBI friend if other than the default is required. For AMPLITUDE CALIBRATION of MERLIN, include at least one of the unresolved calibrators DA193, OQ208, 2134+004 and if possible, the primary flux calibrator 3C286. If this cannot be observed during the experiment, please email the MERLIN scheduler (merlin@jb.man.ac.uk) and the Jodrell VLBI friend, who will ensure that observations of 3C286 are scheduled in a convenient gap. ============================ | 5) GLOBAL OBSERVATIONS | ============================ For scheduling EVN/Global projects, investigators should also consult "VLBA Observation Preparation" at: ====> http://www.vlba.nrao.edu/astro/obsprep/ Note a number of differences between the EVN and the VLBA: - EVN does not have general frequency agility capabilities. - Most EVN observatories cannot perform continuous system temperature measurements. Time must be left before the start of scans for separate Tsys measurements to be made. - Many EVN antennas have much slower slewing times than those of the VLBA. Consequently, observations which involve very rapid source switching cycles may not be feasible at some EVN antennas. =========================================== | 6) PROJECTS USING THE VLBA CORRELATOR | =========================================== For scheduling projects using the VLBA correlator, investigators should consult item 3. in the following: ====> http://www.vlba.nrao.edu/astro/obsprep/before/before.if.txt All projects sent to the VLBA correlator must be recorded using a VLBA or VLBA-compatible MK4 mode. Note that the NRAO change to a software correlator for the VLBA (planned for ~ December 2009) should permit correlation of 1024 Mb/s in Socorro. Recording at the VLBA and GBT is still limited, however, to 512 Mbps. PIs will be assigned a contact person at the NRAO AOC who can assist in planning this type of observation. =================================== | 7) SPECTRAL LINE OBSERVATIONS | =================================== Consult "Scheduling EVN Spectral Line Experiments" at: ======> http://www.evlbi.org/scheduling/evn_line.html - For spectral line observations, ensure that the PHASE-CAL signal is switched OFF by setting pcal = 'off' in program SCHED and by ==> INFORMING ALL RELEVANT OBSERVATORY FRIENDS BY EMAIL *************************************************** since this is still under manual control at some EVN observatories. - Include observations of a strong continuum source for BANDPASS calibration. This source should be observed several times (perhaps the same source can also be used as a FRINGE FINDER - see 3.2) - Find a continuum calibrator close enough to the line source, and schedule this frequently (about once per hour) to calibrate the DELAY (relative phase between frequencies). - Calculate the proper OBSERVING FREQUENCY for the day of observation from the source VELOCITY. These calculations can be done for most conventions by the SCHED program. ================================ | 8) VLBA/MK4 MODE SCHEDULES | ================================ ***************************************************************************** * All VLBA/MK4-mode schedules must be made using the MOST RECENT VERSION * * of the NRAO-Walker "SCHED" program. As of 9 January, 2007 the current * * Version 6.05 is from June 2006. Documentation and instructions on how to * * get SCHED and frequency set-up files can be obtained from: * * * * ===> http://www.evlbi.org/scheduling/scheduling.html * * * * "THE SCHED USER MANUAL" is available on-line at: * * * * ===> http://www.aoc.nrao.edu/~cwalker/sched/sched/sched.html * ***************************************************************************** - For normal continuum observations observers are recommended to use the BAND parameter in an embedded setup rather than an explicit setup file. SCHED then uses its own default frequencies which have been optimised with the EVN in mind. ===> See the SCHED documentation for more details. - Note that SCHED distinguishes between 2 different record terminals at Effelsberg: "EFLSBERG" is the (14 v/c) MK4 terminal. Recordings are made on MK5 disk-packs only. It is the recommended terminal for all EVN observations to be correlated at JIVE or Bonn, and MUST be used for those needing: MK3 modes and/or > 8 BBCs recordings at a bit rate of 1024 Mb/s a phase-cal signal at 18 or 21 cm "EB_VLBA" is the (8 BBC) VLBA terminal. Recordings are made on MK5 disk-packs only. It is the recommended terminal for observations which need: correlation at the VLBA correlator frequency agility between different secondary focus receivers VLBA-style true continuous Tsys measurements - Information for use at the correlator must also be provided in the VLBI schedule. This includes relevant correlation parameters and an email address for contacting the PI. The SOURCE POSITIONS for correlation will also be derived from the schedule, either those explicitly provided or from the correlator/SCHED source database (depending on SCHED parameter corsrcs). Accuracies much better than 1 arcsec are required; make sure you provide sufficiently accurate positions. - The JIVE correlator only works with J2000 source positions; the default is to use those provided by SCHED. If B1950 coordinates are used in the xxxxx.key file, JIVE staff will query the PI before correlation occurs. - Any supplementary information necessary for correlation (e.g. special positions for multiple field-centre correlation) must be provided using the 'cornote' parameters. The following files should be produced (where xxxxx is the experiment code as it appears on the EVN schedule, and ** is the 2-letter antenna code): xxxxx.key - input file for SCHED (created by the user) xxxxx.sum - SCHED summary output file xxxxx.skd - SCHED output file to run most participating telescopes xxxxxcrd.** - control files for EB_VLBA (VLBA and other NRAO telescopes) xxxxxsch.** - human-readable schedule for telescope operators Investigators should CHECK THROUGH the file xxxxx.sum produced ******************************** by SCHED before finalising the schedule. Please report any BUGS to: ====> Friso Olnon (olnon@jive.nl) ============================== | 9) DEPOSITING SCHEDULES | ============================== A computer disk area is maintained at the Ist. di Radioastronomia, Bologna for depositing EVN schedule files, and for retrieving logs and calibration data. Users should ftp to: ====> vlbeer.ira.inaf.it as user "evn" (the password can be obtained from any VLBI friend or JIVE support scientist; or telephone Bob Campbell at JIVE +31 521 596534 or Zsolt Paragi at JIVE 31 521 596536 or Bonn correlator staff +49 228 525220 or T. Venturi at +39 051 639 9370 or F. Mantovani at +39 051 639 9377) Experiment files should be put in directory: ====> vlbi_arch/mmmyy where mmm is the first 3 letters of the MONTH IN WHICH THE OBSERVATION STARTS, and yy is the last 2 digits of the year (e.g. jun00). ====> Contact Tiziana Venturi (t.venturi@ira.inaf.it) for any problems encountered using the VLBEER area. All file names MUST USE lower-case CHARACTERS and MUST begin with xxxxx... , the EVN project code as it appears on the BLOCK OBSERVING PLAN. ===> IF THIS IS NOT POSSIBLE FOR SOME REASON, CONTACT THE EVN SCHEDULER ================================================================== 9.1 For EVN Antennas: Deposit files xxxxx.key xxxxx.skd xxxxx.sum (needed for estimating amount of recording at each station) xxxxxsch.** (for all antennas except VLBA and VLA) xxxxxcrd.eb (if EB_VLBA is used) 9.2 For NASA DSN Antennas (e.g. Robledo): Send an EMAIL NOTIFICATION that the schedule has been deposited on VLBEER to: =====> dsn-vlbi-ops@jjpl.jpl.nasa.gov 9.3 For NRAO antennas in GLOBAL Observations: Observing schedules for the VLBA and other NRAO telescopes (VLA and GBT) need to be sent to, or deposited in, the vlbiobs account at the AOC in Socorro. Consult item 6. in: ====> http://www.vlba.nrao.edu/astro/obsprep/before/before.if.txt EITHER: A) Use FTP to deposit all your schedule files, including the sched keyin file, via ftp.aoc.nrao.edu at the AOC and send e-mail to vlbiobs@nrao.edu to inform the data analysts of your deposit. If `mmmyy' is a code for the month and year of the beginning of your program (e.g., jan06) and `pppppp' is your program code (e.g., gw999x), then all files must be deposited to directory /home/vlbiobs/astronomy/mmmyy/pppppp. Files must have names in lower case. The example FTP session ftp ftp.aoc.nrao.edu Name: vlbiobs Password: ftp> cd astronomy/jan06/gw999x ftp> put gw999x.key ftp> quit deposits a sched key file. The data analysts will submit all relevant schedule files to VLBA and/or VLA operations. If you deposit revised files to the vlbiobs account, then it is your responsibility to alert the data analysts and all stations about the revisions. The vlbiobs password can be obtained from an active vlbiobs user, the data analysts (+1-505-835-7238; e-mail vlbiobs@nrao.edu), or the AOC contact assigned to your program. If you wish to avoid transatlantic or transpacific phone calls then you may contact Walter Alef at the Bonn correlator (+49-228-525220) or Anastasios Tzioumis at his ATNF office (+61-2-9372-4350). The password should *not* be transmitted in an e-mail message. An e-mail user name is given for the data analysts so you can contact them by either phone or e-mail if you experience trouble accessing the ftp site. OR B) Send your sched keyin file via e-mail to vlbiobs@nrao.edu. The data analysts will place this file to the appropriate directory, modify the file for local use, and then run it on the appropriate vlbiobs account subdirectory. If you e-mail a revised keyin file to vlbiobs, then it is your responsibility to alert all stations about the revisions. 9.4 MEETING THE DEADLINE Schedule files MUST be deposited on VLBEER before the deadline given on the EVN block observing plan. After checking at JIVE, observatory staff will download schedules for processing and review. SCHEDULES WHICH ARE DEPOSITED AFTER THE DEADLINE may not receive adequate review and run a much higher risk of failure, for which the Investigator will be held responsible. SCHEDULES WHICH ARE CHANGED AFTER THE DEADLINE create additional dangers, since there is a high risk that some antennas will observe the original version. In the (very undesireable) situation that a PI wishes to deposit or modify a schedule after this date, please note the following policy decided by the EVN Technical and Operations Group: 1) Inform the head of Science Operations & Support at JIVE (Bob Campbell campbell@jive.nl) that you have deposited a late or new schedule, and give the reasons why you have done so 2) Do NOT contact individual VLBI observatory friends 3) Bob will then decide whether the reasons given compared to the time left before the session (observation) justify the risks of accepting a new schedule for the execution of the session. 4) Only Bob can bring the new schedule (any schedule) into the system so that it gets observed. ================================================= | 10) AFTER DEPOSITING THE OBSERVING SCHEDULE | ================================================= 10.1 DURING THE OBSERVATIONS It is not helpful to contact individual EVN observatories during the session to enquire about the observing status of individual projects. Investigators may like to watch their observations taking place in Effelsberg via the webcam: http://www.mpifr-bonn.mpg.de/public/images/webcam.html After the observations have taken place, brief reports on each project from each EVN observatory participating can be found at the Experiment Feedback Facility, accessible via the EVN WWW Home page, or directly at: http://www.evlbi.org/session/feedback.html 10.2 CORRELATION *************************************************************************** * Note that a very accurate source position is necessary for a successful * * correlation; make sure this is available to the correlator staff. * *************************************************************************** Staff at the JIVE CORRELATOR will contact the PI before correlation, as soon as the disk-packs have been received, giving details of the planned correlation parameters. PLEASE REPLY to any email sent to you, even if everything seems to be OK, otherwise the correlation may be delayed. The JIVE correlator project queue can be seen at: ====> http://www.jive.nl/correlator/jive_load.html Staff at the VLBA CORRELATOR will not normally contact the PI before correlation - all relevant correlation parameters will be taken from the schedule file. Disk-packs will be released automatically as soon as NRAO staff are satisfied that the correlation has been completed. PIs should therefore email their AOC contact and analysts@nrao.edu URGENTLY if they have omitted to specify any critical information. 10.3 SUPPORT FOR ANALYSIS JIVE provides facilities and support for the analysis of VLBI data. In particular, PIs of projects being correlated at JIVE or PIs who are inexperienced in VLBI data processing, are encouraged to visit JIVE. Some financial support is also available. For more information, contact: ====> campbell@jive.nl The EVN Data Analysis Guide, available in both html and postscript versions in the EVN Users' Guide web page ====> http://www.evlbi.org/user_guide provides a good place to start for making the reduction of EVN data as straightforward as possible, including how to take advantage of results of the automatic pipeline processing for experiments correlated at JIVE. Most EVN users will start their analysis using the NRAO "AIPS" analysis package. The AIPS Cookbook (chapter 9 is devoted to the analysis of VLBI Data) can be found at: ====> http://www.aoc.nrao.edu/aips/cook.html 10.4 EVN PIPELINE EVN and Global VLBI Observations correlated at the EVN MkIV Data Processor at JIVE are now automatically calibrated via a pipeline process. In particular, the a priori amplitude calibration table (and the associated final ANTAB file), plus various other tables and plots can be downloaded from the Pipeline page on the EVN archive. (Note that the unprocessed station- generated *.antabfs files under the Station Logfiles page of the archive are not directly usable.) A description of the pipelining process can be found at: http://www.evlbi.org/pipeline/user_expts.html 10.5 EVN DATA ARCHIVE The EVN data archive at JIVE is now a central location for obtaining the information you need in reviewing your project: network feedback from the stations, standard plots from the correlation review done at JIVE prior to distribution, pipeline results, and the FITS files themselves. A password can be arranged to download your FITS file(s) from the archive directly. The EVN Archive policy can be found on the EVN Users' Guide in http://www.evlbi.org -- in short, data/images from sources identified as target/private in pre-correlation liason with JIVE will not be made public for one year from distribution (of the last part, if a multi-epoch experiment). The archive can be accessed via: http://www.jive.nl/archive/scripts/listarch.php (or, with less typing via the menu items of the main jive page www.jive.nl). In each experiment, there will be links on the left-hand menu bar to: *) Station Logfiles = sched-based files you uploaded to VLBEER, observing log-files from the stations, other unprocessed station-generated files. *) Station feedback = comments from the EVN stations made during observing the experiment *) Standard plots = plots from the post-correlation review; the cover letter. *) Pipeline = pipeline plots; the ANTAB & UVFLG files used in pipelining; various FITS calibration tables made in the course of pipelining. *) Fitsfiles = FITS files, plus an associated README in case there are multiple correlator passes each with its own set of FITS files. The archive also has a FITS-finder tool, to locate data on the archive that meet the criteria supplied in the data-selection fields. A catalogue of sources observed with the EVN, maintained by Tiziana Venturi, is available at: ====> http://www.ira.inaf.it/~tventuri/cata.html which is also linked in the EVN archive. 10.6 NETWORK PERFORMANCE Users interested in the technical performance of individual EVN antennas can find reports from the Network Monitoring Experiments (NME), observed at some wavebands in each session, at: =====> http://www.evlbi.org/tog/monitor.html and click on "Full network monitoring reports" (the direct ftp link is ftp://ftp.jive.nl/jive/monitor/). Postscript files have names nyywi.ps (or cyywi before 2001) (where yy is the last 2 digits of the year, i is the EVN session number, and w is a waveband code: l=18cm, c=6cm, m=5cm, x=3.5cm, k=1.3cm, u=30cm, p=90cm). The NMEs are also processed by the EVN pipeline, and are available on the EVN archive (all NME data is immediately public). A separate list of NMEs which provides direct links to the experiments' archive pages can be found at: =====> http://www.evlbi.org/tog/pipeline.html 10.7 MERLIN DATA Investigators are welcome to visit the Jodrell Bank Centre for Astrophysics to do the first stage analysis of MERLIN data from EVN-MERLIN experiments. This includes editing, calibration and converting to UV-fits format. Investigators with limited experience, or with experiments which are very complicated, are especially encouraged to visit JBCA where they can benefit from the experience of Jodrell Bank staff in combining EVN and MERLIN data. It is also possible, in some cases, for MERLIN staff to provide the investigator with partly-reduced MERLIN data (by ftp/wget access) in the form of a multi-source AIPS UVFITS file with calibration and other tables which can, optionally, be applied. This is most suitable for continuum experiments where the data recipient has some experience in interferometry data reduction including local access to AIPS (in some cases DIFMAP may suffice). It may be possible to provide similar data for spectral line experiments. ====> Contact Anita Richards (amsr@jb.man.ac.uk) 10.8 RE-OBSERVATION POLICY Any VLBI observation requires the coordinated functioning of a large number of diverse and complex instruments. It may happen that, due to the technical failure of some crucial element(s) of the array, the resulting data set cannot satisfy the scientific goals of the observation, as judged by the investigator, who may therefore wish to request a re-observation. In such cases, the proposer should write to the Chairman of the EVN Program committee by the next EVN proposal deadline, giving details of the failure and the reasons why re-observation is thought necessary. If the EVNPC agrees, and there is no change in the scientific justification for the observations or the resources requested, the proposal will normally be re-assigned for possible scheduling, without further scientific evaluation. The probablility of re-observation will depend on the competitiveness of the original scientific rating. 10.9 PUBLICATION OF RESULTS Publications and scientific papers that use observations from the European VLBI Network, whether it be on its own or as part of a global VLBI observation, should include the following standard acknowledgement: "The European VLBI Network is a joint facility of European, Chinese and other radio astronomy institutes funded by their national research councils."