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Observations: EHT with R2DBE

Modified 18:44, 17 Apr 2018 by rottmann | Page History

    Version as of 08:50, 27 Nov 2024

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    Prerequists


    R2DBE-Procedure

    • Prepare the Mark6 machines (recorder1 to recorder4) for recording. Instructions.
    • Download the vex-schedules (typically found on the EHT wiki) and copy them to /home/oper/shared/schedules on the control computer.
    1. Download from the EHT-wiki to mrt-vlbi or mrt-vlbi2
    2. on mrt-vlbi or mrt-vlbi2: scp {vex-files} oper@vlbicc:/home/oper/shared/schedules
    • Translate the vex schedule

    on any of the recorders (as user oper):

    cd /home/oper/shared/schedules
vex2xml.py -f {vex-file} -s {code}

    NOTE: the two letter code given as {code} must match exactly (case-sensitive!) the code assigned to Pico by the vex file. Normally it is Pv. If in doubt  open the vex-file and check the $STATION section.

    This will create an output file named like the vex file but with an .xml extension (hereafter {schedule.xml})

    Open the created {schedule.xml} file and verify that it is not empty. If it is empty check again the two letter station code you have given in the last step.

    • Start the schedules:

    on all 4 recorders:

    cd /home/oper/shared/schedules
M6_CC -f {schedule.xml}

    Note: starting the schedules can be done at any point prior to the session.

    • Start the automatic gain control:

    on the control computer (as user oper):

    start_eht.py  /home/oper/shared/schedules/{schedule.xml}

    Field System

    The field system is used for driving the telescope and to log information relevant to the observations

    • Download the schedules and copy it to /usr2/sched on mrt-vlbi (the standard VLBI PC).
    • Log into mrt-vlbi as user oper
    • create field system files from the vex schedule
    cd /usr2/sched
drudg {vexfile}
    select station code (typically Pv)
    select option 3 (=make snap) <enter>
    select option 0 (quit)

    This will create a  file:

    /usr2/sched/schedulename.snp

    where schedulename is the name of the vex-schedule + pv (e.g. e17j28pv)

    • start the field system. On mrt-vlbi go to the "Field System" desktop. Click on the "Field System" icon.
    • Ignore any errors concerning dbbc or mk5
    • In the oprin terminal issue:
    schedule=schedulename

    Troubleshooting

    Restarting daemons: need new input_streams, m6service