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Checklists for a VLBI session

One Week before (for VLBI friend)

        -schedules
                -are they all present on wsrt00?
                -are they correct?
                -remove "STOP" from schedules
                -begin local editing on procedures
                        (depends on wavelength and mixing scheme)
                -start conversion to STFMA; check error messages
                -transfer to field system computer
                -check waarnemers to observe nights/weekends.
        -tapes
                -are there enough? (Keep a reserve of at least 2)
                        If not: order more from Bonn
                -begin prepassing. Label and remove bad tapes.
                -check for unerased tapes (yellow or red dot); remove.
        -clock offset
                -is offset from GPS >10microsec?
                        If more ask Friend about reset
                -is offset stable?
                        If drift >0.1microsec/day ask Friend about reset
        - System
                - check mixing scheme and control codes
                        (STUURC/DEVCO/PRFLAG/RECON)
                - check which frontends are in the tied-array
                        equalizers with no signal onto noise source
                - begin "Het inregelen van het meetsysteem" when frontends 
                  are in the telescopes.
                        Telescope positions
                        Total powers
                        Delay (weglengte)
                        System temperatures
                        Phase zeroes
                        Dipoles
        -Mk3 rack
                - Is field system working? (can check with prepass)
                - check formatter and field system time.
                - check VC frequencies for standard setup (counter)
                - Check humidity at tape unit near heads <35%
        -Tape unit/heads
                -Check readability of cal tape.
                -Record some noise on all tracks of a new tape
                 and then play back
                        Check parity errors
                        check formatter
                -Now record another pass and repeat checks.
                        Erase this tape.

Two days before (for VLBI friend)

        -Schedules
                -Check conversion to STFMA
                -Check edits of procedures.
        -Adder
                -Check correct telescopes in adder for each band
                 (see also Phasecal)
        -System
                -are phase zero and Tsys values correct for all setups?
                -Check total power from adder (on/off source)
                -Check spectrum at Mk3 IF
        -Mk3 rack
                -Are total power levels correct? if not change attenuators.
                        (see separate checklist for ASTI/Mk3 total powers)
                -Check VC frequencies for setups to be used.
        -Phasecal
                -Check that the LO2 comes from a PTS (not fixed synthesizer).
                -Choose one telescope (without frontend) to use for
                 phasecal injection at the equalizer.
                -In FIXPA set the position of that telescope to 3000m
                 (so that fringe rate is zero) and set the correct value of
                 LO2.
                -Inject the phasecal signal at the correct equalizer and
                 adjust the power level (same as inputs to other equalizers).
                -Add the signal from that equalizer into the tied array.
                -Check with spectrum analyzer that the phasecal tone is in
                 the correct place in each video converter.
        -'Instraal test' with one frontend.
                -broadcast in band to check mixing scheme (to 1Hz)
                 with the phase-locked impact diode system.
                -check polarization by helix (only possible at 6,18,21cm)

During Observations (for Waarnemers)

Taking over a shift

FILPRP
      Filled with correct observations?
      No gaps >15min?
STMET
   Compare with checked default observations. Are they correct?
CALLM
      Are correct telescopes being checked?
      Is continuous checking on?
      Check with test option that CALLM is running
Field System
      Is correct schedule running
      Check for any error messages
      Note in the log which telescope are in the array
      Check if the phasecal signal is present and the levels in each VC
Formatter
      Check time with WSRT clock (and DCF77)
      Check 'pass' lamp on
      Check correct mode is in use (with schedule)
      Check correct sample rate (2 x video bandwidth)
Video Converters
      Correct frequencies (see session book for defaults)
      Correct bandwidths (see session book)
Adder box
   Check that the correct telescopes are added in each DCB band
   (modulation switch now under software control). Check to see if the
   phasecal telescope is included.    
Total powers from telescopes
      Check TOPOR levels correct
      Check that Equalizers with no input from telescopes on noise source
       (and one has the phasecal signal)
ASTI total powers
   Check total power levels correct. These should be between about 0.5
    and 2V, and attenuators set according to the checklist. (see the
    separate ASTI total power setup checklist). A paper copy of the
    attenuator settings should be stuck near the ASTI.
Chartrecorder
   Check that strong sources can be seen as a step. Note that this
    is only possible for more than 1 telescope in the tied array,
    and the steps are only typically a few percent of the total
    power.
MOSYS 'temporary solve' output
   Are the solutions for strong point sources good?
      0.98 < Gain < 1.02
      -30deg < phase < 30deg
      flux density (if known) correct within 2%
Phone system
   on'Night' position at weekends and in evenings

Checks during a shift

Field system
      Find the cause of any error messages, and fix them. A useful
       list of SNAP commands in common use is available.
      Use STATUS command to check the schedule operation. Note the
       times of coming tape changes, and when the schedule ends.
      Note any system changes and general system information (such
       as telescopes in array and weather) in the field system log
       using the " command
Video Converters
   Check LO frequency, bandwidth (from session book) and total
    power levels (0.2-1.2V).
Formatter
   Check time display and 'Pass' LED.
Chart recorder
   Note the UT time and day number
DAT tapes
   Check that the correlator output for the session is saved
Logsheets
   Keep up to date. Note any system changes
Logbooks
   Both VLBI and WSRT. Keep both up to date. In the VLBI logbook
    please note:
      Clock offset (at least daily)
      Which telescopes are in the tied array (at least once per experiment)
      Which tapes are used
      Whenever system changes occur
MOSYS 'temporary solve' output
   Are the solutions for strong point sources good?
      0.98 < Gain < 1.02
      -30deg < phase < 30deg
      flux density (if known) correct within 2%
   If these are consistently bad, check with VLBI friend about a
   new online calibration.
FAX
   Check for any relevant messages

Checks before going to sleep

CALLM
   Check it is running with the correct telescopes in
Semafoon
   Check operation using CALLM test option
Telephone system
   Check that it is working (phone 0593-592421) and on night
   position
Alarm
   Set alarm for tape changes (allow 15min) and schedule changes
   (allow 30min)

Checks after VLBI session (for VLBI friend)

System
        Remove the phasecal signal from the equalizer.
        Return the online parameters (in FIXPA) to correct values:
           The correct position for the phasecal telescope
           The correct value for LO2 DCB (if using fixed synthesizer)
        If a single-dish setup was used, return the telescope to
         the array.
Log files
        Check that all the log files are correct
        Transfer the log files to Bologna (astbo1.bo.cnr.it)
Cal files
        Check that all the calibration values in the files are correct
        Transfer the cal files to Bologna (astbo1.bo.cnr.it)

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