Checklist for VLBI observing on the GBT

Links:

"Mark5C/RDBE system": Brief Project Startup Checklist

"Legacy system": Very Brief Project Startup Checklist

Some (but not all) VLBI experiments will be scheduled dynamically, which means that they will be scheduled for one of two possible dates, a "primary" date, and an "alternate" date. Thus the experiment will appear twice on the resource calendar. This information will also appear on the GBT VLBI Project Summaries web page, which will show both the prime and backup dates.

The PI needs to make the dynamic decision by 11 AM for a project that takes place between the following 5 PM and a day later. This is just the same as the decision process for all dynamically scheduled GBT observing.

The operator should check the daily scheduling e-mail which tells the results of the daily decisions. If the decision is for the primary day, then the procedures for running the VLBI experiment are the same as before.

But if the decision is for the backup date, then the operator needs to check some things:

To re-generate the OBSERV.TX file for the alternate schedule, log into "gbvlbi" and type : "obset"
Obset will list the possible alternate projects that it knows about. Type a number to select which one is the next project to be run on the alternate date. If the next project runs on the primary date, type "P".

Then one should check the OBSERV.TX file to make sure the "alt" project has been set and that the start and stop times are reasonable.

Note that obset should be run before the primary schedule would have run; otherwise the Mark5 will start recording on the primary schedule.

Note also that when you have changed OBSERV.TX by running obset (or by editing it directly) you have to re-boot the station computer.

Astrid Files The files for the alternate schedule should have been loaded into the Astrid database. The scheduling blocks will have "alt" in their names. The operator should run these "alt" blocks instead of the normal ones whenever the backup schedule has been chosen.

More changes

You will notice there is a new "alt/" directory under ~gbvlbi/obs/ -- this is where the alternate versions of the schedules will be put. Normally the retrieval of project schedules into these directories will be taken care of by the "VLBI friend" (Frank or Jules) well before the projects are supposed to be run. The procedures "fetchvobs" and "vlbprep" have been modified to download both the primary and alternate schedules from Socorro and put them in the ~gbvlbi/obs/ or ~gbvlbi/obs/alt/ directories. Both primary and alternate scheduling blocks will be imported into the Astrid database, and again this normally will have been done by the "VLBI friend".

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Check Disk or Tape Supply

• Try to get disks delivered at least a few days before the experiment so there is time to let the temperature stabilize.
• Communicate with the VLBA tape librarian using the e-mail address 'vlbatape@aoc.nrao.edu'
• When disks or tapes are received, and when disks or tapes are shipped out to Socorro, use the TRACK system to record the receiving and shipping of tapes.
• To get into the TRACK system, use the web browser, go to
  the TRACK web page: http://magnolia.nrao.edu/track/
  Login: gbvlba
  Enter data as directed by the web page.

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Download Schedules

  There are 4 methods of downloading files:
	a) automatic method using program "fetchvobs"
	b) download through the aspen web page.
	c) download EVN schedule from "vlbeer"
	d) download from Goddard.
  
  Note that you should check for file updates a few hours before the 
  experiment just in case the schedules have been changed.

  First, log into any unix machine as "gbvlbi".  Contact the GBT operator
  for the password.
  $ cd obs


  -----------------------------
  A. Automatic file downloading
  -----------------------------
   Run the new python script "fetchvobs" which downloads schedules from Aspen.
   "fetchvobs" will fetch all files from the present month; or you may
   give it the month and year as "mmmYY" (e.g., "jan06").

   - log into a Linux machine as "gbvlbi"

   $ cd ~gbvlbi/obs/incoming
	[we use the 'incoming' directory to receive the files]

     [clear out the incoming directory:]
   $ rm *.*
   $ rm alt/*

     [Fetch the files: 
	
   $ fetchvobs 

     or : fetchvobs mmmYY
     or : fetchvobs mmmYY projcode  [to download just one project]

     [wait a few minutes for the file download to finish]

     The incoming directory will contain all the *.gb files for the
	projects that use the GBT in the selected month.

    $ vlbaprep
        
        vlbaprep creates the files for Astrid, named *obs00*, *obs01* etc.

	Copy the '[project]*.*' files up one level to  ~gbvlbi/obs/

    $  obset 
     In the ~gbvlbi/obs/ directory, obset creates the OBSERV.TX file
     which tells the station computer which scheduld to run when.

  Print out the schedule files:
  $ a2ps -f6.5 [project]*.gb  

  or
  $ opsprint [project]sch.gb
    opsprint prints the "sch" file on the operator's ops4050 printer.

  -------------------------------------
  B. Downloading through the web page --
  -------------------------------------
  Use the link for the 
  VLBA-Aspen web site 

   Click on the desired month/year
	for example "nov02" will get November of 2002.
   Click on the project name.
   
   The files of interest are the ones with a '.gb' extension.
   Click on the   '---crd.gb' file, choose 'save as' in the file menu.
   Click on the   '---sch.gb' file, choose 'save as' in the file menu.

  $ a2ps -f6.5 [project]*.gb     {print out schedule files}

  
  -----------------------------------------------
  C. Download EVN schedule from "vlbeer"
  -----------------------------------------------
    The standard place for EVN schedules is "vlbeer"
    Sometimes if a project is using the EVN and the GBT is the only NRAO
    telescope, the files will not have been put on aspen.
    Of course, the user should really put the files on aspen.

    But just in case they don't, use the  link for the "vlbeer" web site. 


  ------------------------------------------------------
  D. Downloading schedules from NASA (geodetic projects):
  ------------------------------------------------------
        ftp cddisa.gsfc.nasa.gov   {user=vlbigeo }
        cd mmmyy
        get [project].skd

Set up Schedules

  After you have downloaded the schedule files:

  Look in the .key file to find which correlator (Socorro or JIVE)
   will be used, the PI name and email address.

  Look through the schedule files; the [project]sch.gb file is easier
  to read than the [project]crd.gb file.

  Take note of: 
	a) start and stop times and dates
	b) how many disk packs are required
        c) Get the number of GigaBytes by running "cksched [project]crd.gb"
	c) when are disk changes needed?
	d) which receiver is required
        e) starting AZ and EL.

  Check the start and stop times versus the GBT schedule: tell the scheduler (Carl or Jules) about any discrepancies.  

  Edit the project summary web page to summarize the basic information.
The project summary web page should have the correlator, starting AZ & EL, and required number of GB.

Run the handy python script "vlbprep" :

• You should be in the ~gbvlbi/obs/ directory.
• Remove earlier *crd.gb, *cr.gb, and *.turtle files from the ~gbvlbi/obs directory. (i.e., earlier files for the same project you are presently working on)
• Any files for projects that have already run should go into the "oldsched" directory.
• Copy the "crd" files for all the upcoming experiments into the ~gbvlbi/obs/ directory.
• type: vlbprep
• vlbprep produces: a series of Astrid scheduling blocks for each project (named [projcode]_obsn[_pk].turtle).

type: "obset" to create the OBSERV.TX file.

The following steps in the box are what has been replaced by running "vlbprep". Ignore the stuff in this box!

- Edit the "OBSERV.TX" file: - Log in to any linux machine as "gbvlbi" cd obs vi OBSERV.TX {or use your favorite editor} {duplicate the last line of OBSERV.TX, then modify the line to contain the name of the *crd.gb file, change the start time to now, and the stop time to a few minutes after the end of the schedule.} ** Note that the *crd.gb file names must contain no more ** than 8 characters before the dot! ** Shorten the file name if necessary! - Make the Observing Blocks for astrid. Run the program "vlbastrid" and give it the name of the [project]crd.gb file. vlbastrid [project]crd.gb (this will produce 3 or more files whose name starts with the project code and ends with "obsnn.turtle" in which the "nn" is a sequence number.)

  - print a summary of the astrid files:
	   a2ps [project}__sum 

  - Print the schedule files:

	a2ps -f6.5 [project]crd.gb
	a2ps -f6.5 [project]sch.gb   

Import Schedules into Astrid

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Notes on Frequencies

  Have a look in the  "....crd.gb" file at the "extlo" and "extlosideband"
   parameters.  These will each be set to a pair of parameters, for example:

	extlo = (1,  5.6000000000)
	extlosideband = (1,L)
	extlo = (3,  5.6000000000)
	extlosideband = (3,L)

   - the first of the pair is a number 1,2,3, or 4, which corresponds
	to IF input ports A, B, C, or D of the DAR.  

   - the "extlosideband" 2nd parameters should be Lower (L) for 
	receivers of 10 GHz and less (up thru X-band),
     and should be Upper (U) for higher frequency receivers (KU band and above).

   - For Upper sideband receivers, the extlo value will be the desired
	sky frequency (Fsky) minus the BBC frequency, for all backend
	channels.

   - For Lower sideband receivers, the extlo value will be the desired
	sky frequency (Fsky) plus the BBC frequency, for all backend
	channels.
   
   Note that in the "...sch.gb" file, near the top, will be the desired
	sky frequency (Fsky) for each channel.  
	These are labelled: "Next scan frequencies"

	Below these Fsky values are the BBC frequencies for each channel.
	These should of course agree with the BBC values in the "...crd.gb"
	file.

    GBT LO settings: 

	The nominal center of the IF3 band for VLBI observing is 750 MHz.
	Assuming the midpoint of the BBC frequencies is 750, then
	we set the GBT rest frequency (Frest) as follows:
	   Frest = extlo + 750MHz for upper-sideband receivers,
	 and
	   Frest = extlo - 750MHz for lower-sideband receivers,

	We set the LO2 frequencies in the converter rack to
	   either  12750 MHz for receivers that user IF1=3000,
	   or      15750 MHz for receivers that user IF1=6000,
	   or      10830 MHz for receivers that user IF1=1080.

	This will make Frest convert to 750 MHz going into the VLBI
	backend, and the BBC settings in the "...crd.gb" file will
	tune in the correct sky frequencies.

        In most cases, the midpoint of the users set of BBC frequencies
	will be something other than 750, hence one would alter the above
	accordingly.

     The program "vlbastrid" will determine Frest and lo3freq from the
     ...crd.gb file to put Frest at the midpoint of the desired set of
     frequencies and to make the effective LO equal to "extlo".
  

Do System Prechecks

  These checks should be done a day or two before the experiment so 
  any problems that show up can be fixed.
  Some of these checks can also be immediately before the 
  experiment, if there is time, just to make sure everything is ok.

  First check the the station clock,
  and set up the screens  as described in the following 
	sections.
  - After the schedule file is downloaded, ("fetchvobs", "vlbprep", "obset")
	has been edited, reboot the VLBA station computer to start
	the observing system.

  If you have control of the GBT receiver and LO/IF system,
	run Astrid and submit the first non-peak scheduling block for the 
	experiment.

	- check the desired receiver channels connect to the 
	   correct VLBA DAR channels.
	- adjust the attenuators in the converter rack to put the
	   power levels in the VLBA IF distributors in the range
	   about 10000 to 20000.
	- Turn on the test tone in LO1 and use a spectrum analyzer
	   to check that the tone is at the right frequency in the
	   BBCs.

	The following can be done with the VLBA back end, even if you
	  do not have control of the GBT front end and LO/IF system:

	- Check that the BBCs are set to the correct frequency and
	   that their LOs are all locked.
	- Check the LO signals with a spectrum analyzer.
	- Check the "formatter errors" and "system check" displays.
	

• Make sure all the hardware is powered on:

   - Check that the DAR, Recorders, station computer (VLBAGB), Mark5,
     and "gb-cc" are powered on.
   - "gb-cc" is called the "new station computer"
   - The computer "gb-cc" runs the status checker (vgstatus), so make sure
     it is up and running.
   - If power has been off, refer to  power off/on instructions. 
   - Everything should be powered on at least an hour before an experiment starts.
   - If no experiment has been run for a few days, it is probably a good idea
  	to re-boot the station computer (VLBAGB).
  

• Files should be set up: "crd" file and Astrid files should be present in ~gbvlbi/obs/ directory, and OBSERV.TX file should have been edited to include the current experiment "crd" file. (Refer to "Set Up Schedules", above).
• Check that status file is updating: bring up the web page GBTVLBAStatus and check that the UTC is within the last few minutes (if not, type "stopvgstat" and wait a few minutes), and also that the "Clock" value is less than a few thousand (if not, the station timer on the VLBA_DAR rack may need to be reset).

B. GBT things:

• Correct receiver is rotated in place, and selected in the ScanCoordinator.
• If C-band or higher frequency, check that dynamic corrections are running.and that the active surface is running in FEM mode.
• If S-band or lower frequency, active surface should be in "zero points" mode and dynamic corrections should be off.
• Check that the "gbtstatus" display is updating and showing the correct antenna coordinates, source, and time.

Check clocks; set station clock.

• First, check that 'Site Time' is synchronized with GPS.
  • Compare the GPS display with the IRIG display. They should be on the same second. (also check that the year, month, and day is correct!)

• Next, check that the VLBI formatter is synchonized with SiteTime.
  • Check "clock" on the web page: GBTVLBAStatus
  • The value should be less than +/- a few thousand.
  • If not, push the reset button on the VLBA timing module. (red button near lower left of DAR rack)

• Set the VLBA station clock.
  • (logged into any unix machine) Type 'rs' to bring up the RSCREENS.
  • Bring up the 'OBS-->CLOCK' screen.
  • Check the year, day number, hour, minute, and second:
    they should agree exactly with the GPS display.
  • To double check, or if there is no GPS display:
    Call up the USNO master clock ( 202-762-1401 )
  • Use the CLOCK screen to adjust the station clock, if necessary.
    Make sure the station clock agrees with USNO or GPS.

Start Screens and check "gvstat"

• Log in to a convenient Linux machine ('naiad' for example) as 'gbvlbi'
• Check that the "gvstat" demon is running.
  • bring up the web page: Status of GBT_VLBA Operation
  • Check that the correct source and project are showing under "VLBA obs" and "Project".
    check that the UTC time is within the last few seconds.
    (If not, type : "stopvgstat" and check again in 3 minutes)

• Type 'rs' to start RSCREENS.
  • OBS-->CLOCK to check that the clock is on the right second.
  • FORMAT-->FORMATERR to check the formatter has no errors.
    (if there are formatter errors, see "clearing formatter errors")
    
  • after initial checks, go to OBS-->DAS
    keep the OBS-->DAS screen up during the run to monitor the experiment.
  • Also bring up OBS-->FLAG screen to monitor the on-source status.
  • Check that the DAS screen shows the correct project and source:
    if not, do OBS-->REOBS.
    if OBS-->REOBS does not fix it, reboot the station computer.

• Start the CLEO Status, IFRack, and ConverterRack screens.

Recording on Mark 5 disks:

Fill Out the Disk Labels

• Disk serial number
• station code: GBT_VLBA
• UT Date and time when the Disk is mounted.
• UT Date and time when the Disk is dismounted.
• names of the projects that are on the disk.
• If the disk is not going to Socorro, make a note of it.

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   Make sure that 'gbvlbi' is in the Gateway.

   Log in to one of the Linux machines ('naiad' for example) as 'gbvlbi'
	-- type: cd ~gbvlbi/obs/
	-- type: astrid
	-- select "work online with control of the telescope"

	-- in the astrid "Edit" tab, select the project code.
           If the correct project code is not in the list, then select "AVLB".

	-- Import the scheduling blocks and save them to the database, if
		this had not already been done.

   Ask the operator to set the scan number (usually to 1).

   Make sure the antenna drives are activated and it is ready to run scans.

	-- select the "run" tab in astrid.
	-- set the project code if necessary.

	-- in the "Session" box, type the session code,
           or if you had used project code AVLB then type in the 
           VLBA project code as the session:
	    This is the first 5 or 6 characters of the turtle file name. 

	-- For the "Observer", select the project PI if his name is there,
	   otherwise use your own name.

   - Submit the first observing block,  whose name ends in _obs00_pk.turtle
   - This will do a peak and optionally a focus at a position near the 
	first source in the observing list.
	(Focus only for observing at frequencies >= 8 GHz).
   - Check that the peak and focus look good.
   - Check that the antenna is on the correct Azimuth wrap !

   - Run the first non-peak observing block, 
	whose name probably ends in _obs01.turtle
   - This will configure the system for VLBI and will move to the first
      source to be observed.

   Make sure the antenna starts on the correct wrap!! 
   --To do this, consult the [projname]sch.gb file which lists
     az and el coordinates.
   -- make the GBT azimuth match the azimuth of the first observation.

Set IF Levels

• In the IF Rack CLEO screen, balance the IFs.

• In RSCREENS, bring up the OBS-->DAS screen.
• Use the Converter Rack CLEO screen to adjust the attenuators:
  put the VLBA IF power levels in the range 10,000-20,000.
  

   Note: Usually Rack A, converter modules 1 and 5, are used for 600MHz, 
	800 MHz, L-, C-, Ku-, K-, and Q-band receivers.
	Rack B, converter modules 9 and 13, are used for S-band and X-band receivers.

     ***This is how the VLBA IF channels connect to the GBT converter rack:
	-----------------------------------------------------------------
	IF 1:1 is VLBA_DAR:A  (RCP, from Cnv.rack A, CM5)
	IF 1:2 is VLBA_DAR:B  (RCP, from Cnv.rack B, CM13)
	IF 2:1 is VLBA_DAR:C  (LCP, from Cnv.rack A, CM1)
	IF 2:2 is VLBA_DAR:D  (LCP, from Cnv.rack B, CM9)
	-----------------------------------------------------------------

   For example, if using S-band or X-band receivers, adjust the attenuator
   of converter module 9 to bring the IFPower 2:2 to near 16000,
   and CM13 to bring IFPower 1:2 to near 16000.

   For the other receivers, CM1 adjusts IF 2:1 and CM5 for 1:1.

  - In SCREENS, run OBS-->CHECKALL  : there should be very few messages.
 

Check IF paths and frequencies

• Use the IF Manager either by itself or in the CLEO STATUS screen to check that frequencies and bandwidths are correct.
• Consult the file "[project]_setup.py" which is one of the files that the program "vlbastrid" produced. In that file will be a set of configuration commands labeled "Vsetup1".
• The "restfreq" value should be the sky frequency in the IF Manager; the "lo3freq" should be the "IF" in the IF Manager. The bandwidth in the IF Manager should be greater than or equal to the bandwidth in Vsetup1.
• The polarization for VLBI is almost always circular, and the sense (RCP or LCP) should be as in the above table.

• For hardcore users you may also :
• Inject a test tone at the sky frequency for each BBC; use a spectrum analyzer to confirm it appears at the right place in the BBC spectrum.
• Check the phase cal level (if requested).

Check the Logging system

  Log in to arcturus as 'gbvlbi' :
	$ ssh arcturus -l gbvlbi
	$ cd 
	$ cd mdata/MDA
	$ ls -lt | head

	Check that there is a '.mda' file named with today's date
	that has been updated within the last few minutes.

  Now check that this file is also being written to the jansky
	machine in Socorro:

	$ ssh jansky -l gbvlba
	$ lsgb

	(this will list the most recent files in the log area on jansky.
	the most recent file should have been updated in the last few
	minutes -- note time is Socorro is 2 hours less than Green Bank)

  Viewing the VLBA log file 
      Log into "gbvlbi" on yed.
	(Note "seelog" runs only on solaris machines)

	cd /users/gbvlbi/mdata/MDA
	ls -lt | head                 {get the name of the current log file}
	seelog MMMdd.mda | less   {lists the log in ascii}

	seelog MMMdd.mda | grep GPS  {check GPS data is being logged}
	seelog MMMdd.mda | grep WEA  {check weather data is being logged}

	-- if phase cals are being used:
	seelog MMMdd.mda | grep PCALX | less   {levels should be 2-5 %}

	-- Check Tsys
	  Look up the Tcals for the frequency being used.
	
	  seelog MMMdd.mda -cal tcal tcal | grep POWER | less

        -- Check onsource/offsource times:
           seelog MMMdd.mda | grep LOG | less

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Check Progress of Experiment.

  - in RSCREENS, use OBS-->DAS
  -            then: OBS-->FLAG

  - Use the printed *sch.gb  and  *crd.obs  schedule to follow the observations.

  - Check that the OBS-->FLAG screen is showing the telescope on source
    ("DATA OK") when it is on source and 
    also that it shows "Telescope position error too large" when off source
    or slewing between sources.

  - Every few minutes, check the IF power levels in the OBS-->DAS screen,
    and re-balance the IFRack if they go below 4000 or above 40000.

  About every half hour:
   - check that the disk is writing when it is supposed to be,
   - do CHECKALL (in the 'rs' screen)
           note: ignore tape recorder errors, "REC1" or "REC2".
   - do FLAG (in the 'rs' screen)
   - is the GBT on the right source?

Log weather conditions and other information.

  - Log unusual weather conditions that might affect the data, such as snow,
  heavy rain, and high winds.  The temperature, pressure, wind speed, and dewpoint 
  are being automatically logged, so no need to mention them.

  - Log any interruption in the observing schedule.

  - Log anything that compromises the data, such as a receiver warming up.

  - Include these messages in an e-mail that you send after the
	experiment is over.

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Dealing with Problems.

   A. Powering down 
	If the VLBA equipment needs to be powered down, there
	is no particular sequence that is required.
	DAR: turn off all the switches on the power supplies, which
		are near the top of the rack.

        -- Mark 5: refer to  Mark 5 Operations Guide 
	for powering the Mark 5 down and up.
        -- briefly for Mark 5:
             Log into the mark 5 with the login account "vlbsoft"
             to power down: /sbin/poweroff
             to reboot : /sbin/reboot

   B. Powering up  
	Turn on the VLBA DAR rack by turning on all the DAR power supplies.

	Turn on the power switch on the Mark5: it is at the lower left of the front.
	
	Turn on the power switch for the station computer
	  ("VLBAGB" in the rack just under of the mark 5.)
	Turn on the power for the Linux machine "gb-cc", which is
	in the rack under the old station computer.

   C. Logging in gb-cc
	Log in to gb-cc using the login name "gbvlbi"

   D. Open a console window for the station computer 
	Open an xterm by pressing the right mouse button.

	In an xterm, type: 'minicom vlba'

	-- this opens the console for the VLBA station computer
	
	Hit the CR, and you should see  the  'GB->' prompt.

   E. Re-booting the station computer (vlbagb) 
         (Also refer to: Rebooting the station computer )
	If power has been off, wait until everything is back on,
	especially the machine "yed".
	then reboot vlbagb.

        Either:
         a.  push the red reset button

	 b. If you see a 'GB->' prompt in the console window, type:  reboot 

	 c. If you see '[VxWorks Boot]:'  ,  type:  @  

   F. Initialize the hardware 
	After vlbagb is up and running, bring up another xterm.
        (you have to have already logged in as "gbvlbi")

	and type 'rs' to bring up the screens package.

	To set the MCB interfaces, do  MCB-->SETALL

	[obsolete: For each of the two recorders, do  PARM-->RECPARM-->SEND]

	Then re-sync the formatter 1pps to the site time 1pps by 
	  pushing the reset button on the Station Timer module.
	  (Lower left corner of the front of the DAR rack).
	  Hold the button down for 1 second.


   G. Clearing Formatter Errors 

	! NOTE: the following formatter errors are ok; !
	!    no action is needed if you see :          !
        ! 	Quality Analysis Module Error          !
	!	  Channel A Clock Error                !
	!	  Channel B Clock Error                !
    
        1. in RSCREENS, FORMAT-->FMTERR screen, push the RESETMCB button.
	 if errors do not clear, 

	2. in FORMAT-->FORMAT screen, reset SRATE, wait for formatter
		to finish configuring, then repeat step 1.

        3. do OBS/REOBS
        4. if problems persist, reboot station computer.

	if errors still do not clear, CALL FOR HELP !

	 The following might help if you are desperate:
	 5. reboot the formatter controller single-board computer.
	    After that you have to do:
		MCB-->SETALL
		OBS-->REOBS
	    and repeat steps 2 and 1.

   Other weird stuff (part1) -- OBSOLETE ! 
	You should mount the tapes after you reboot the station computer.
	If the tapes have already been mounted and there is some need
	to reboot, the station computer will pick up the tape VSN number
	from drive 1 during the reboot, because it has a bar code reader.
	It will not pick up the VSN from drive 2.  So you should 
	re-run the "Mount" procedure on the tapes after re-booting.

	Alternately, you can give the station computer the VSN numbers
	without having to re-run the mount command by typing at the
	vlbagb console:  tapetypeset(tapenum, VSN)
	for example, to set the VSN for drive number two: 
		tapetypeset( 1, "EVNT0262") 

   Other weird stuff (part2) -- OBSOLETE ! 

	Sometimes the Mark5 disk packs have both a VSN and 4-digit CRCC code
	on them (you need both for entering in the TRACK system).
	But sometimes there is no CRCC code label on the disk pack.
	You can find a CRCC code for any VSN number by typing the "crcc"
	command to the vxWorks prompt on the station computer.
	For example, type:   crcc("EVNT0262")
	the reply includes several numbers, one of them is a hex number;
	that is the crcc code.

   Other weird stuff (part3) -- OBSOLETE ! 
	When not using the Mark5 recorder, do the following,
	(logged into arcturus as gbvlbi: )
	
	rcmd disc stmode gb

	(this sets the Mark5 to pass 32 tracks directly through
	to tape drive 1.)

   Other weird stuff (part4)  not obsolete 
       If you have to change the password for the gbvlbi login:

       1. change the vxWorks boot-up parameters:
          a. reboot the station computer, but hit a key before it starts up.
             that way you get the boot menu.
          b. do the "C" command, fill in the new password.

       2. get a new password hash by logging into a solaris machine
           and running "vxencrypt" in ~gbvlbi/bin/

       3. edit the "startup.gbt file in ~gbvlbi/code_mk5/ :
            put the new password hash in the command: "loginUserAdd"
            for the gbvlbi login.

   Other weird stuff (part5)  not obsolete 
       If the rscreen DISK screen indicates: "VSN INVALID" :
         a. "offline" the unit from the DISK rscreen
         b. log into the Mark5
         c. run "tstMark5A" and enter:
              > protect=off
              > vsn=MPI-0603    [or whatever the new VSN is]
              if you get an error that might mean a module problem.
              check the vsn with:
             
              > vsn?
    
              if you get a good response, put the unit online again
              and log out of the Mark5

Dismount and Send Disk Packs to Socorro.

  - Make sure you put a red dot on the label and that the
	label information is filled out.
  - The station name is GBT_VLBA.
  - Make sure that the disk serial number is written on the outside
    of the shipping box.  Put a note on the case that it should be sent to 
    Socorro (or whichever correlator it is supposed to go to), 
      and put it in the mail room.  
  - Tell Sherry to give you the airbill numbers.
    After FedEx picks it up, get the airbill numbers and use the 
    TRACK system  to record the shipment.

  - (remember the TRACK login is 'gbvlba' with pw= track)

Send email to Socorro.

  Write an e-mail message describing any problems that happened during
  the run, missed scans if any, and the tape numbers.
  - address it to the PI and :  vlbaops, analysts, gbtops, gbtobssum.

Shut Down.

   - To shut down the SCREENS package, type "CNTRL-C A"
   - Shut down all processes and log out.

to top

as of June 2010, rev Dec 2012

- DSS schedule: https://dss.gb.nrao.edu/schedule/

- vlba setups (observing summaries) web page:
    http://www.gb.nrao.edu/GBT/setups/vlbsetup/vlbsetups.html

- vlba project archive list :
    http://www.gb.nrao.edu/GBT/setups/vlbsetup/vlbarc.html

For editing these web pages, you can get to vlbsetups and vlbarc 
quite easily if you are logged in to "gbvlbi":

   cd ~/public_html/vlbsetup

Many of the following instructions assume you are logged in to "gbvlbi"
Note that the machine "spock" no longer exists.
To log into gbvlbi, use "gb-cc", also known as "gbtvlba".

For example:
  $ ssh gbvlbi@gb-cc


------------------------
Instructions
------------------------
1.  Check the DSS schedule as far in the future as you can,
    and revise the "vlbsetups" web page to match the DSS schedule.

2.  Retrieve schedules from Socorro ("fetchvobs")
    check if any schedules were updated relative to what was previously
    downloaded.
    Retrieve them into the ~gbvlbi/obs or the ~gbvlbi/obs/incoming directory.
      cd ~/obs/incoming
      fetchvobs
      vlbprep
      [mv files to ~/obs]

2.5 Retrieve RadioAstron schedules:
      cd ~/obs/RAincoming
      fetchRA
      vlbprep
      cp *.vex ~/localscripts
      mv re* ..

      (ref wiki page for  RadioAstron procedures. )

3.  Enter information (start/stop times; disk usage; starting az/el) into
    the vlbsetups web page.  Take note of which correlator the disks should
    go to, and make sure the correlator is indicated in the web page.

    Run the handy program "vpinfo" in the ~gbvlbi/obs/ directory to make a
    listing of starting az/el disk usage, etc for all projects that have
    been loaded into that directory.

4.  Check for any discrepancies between the DSS schedule and the schedules
    retrieved from Aspen. e.g., start or stop times, receiver.
    If problems are found, consult Toney to resolve them.

5.  Convert the "crd.gb" files by running "vlbprep".
    If retrieving files into the "incoming" directory, and there are
    already files for these projects in ~gbvlbi/obs, compare them
    using the "diff" command to see if there have been any changes.
    You only have to check the "crd.gb" files.

5.5  - New feature, for multi-beam receivers, you can specify an alternate
       beam to use for observing.  For example if there is a problem with
       beam 1 of the KFPA, one can use beam 3 instead, by creating a file
       named "newbeam" in the directory where you run "vlbprep".
       Put the beam number in the first line of this file.
       But be careful to check the alternate beam has compatible routing
       through the IF system -- this feature is not fully supported!

6.  Move all the project files into the ~gbvlbi/obs directory,
    except for any that are redundant.

7.  Create the OBSERV.TX file by running "obset"

7.5 Create the RunVLBI files with CheckVLBI:
     cd ~/localscripts
     [ or cd ~/scripts , if using new wideband system ]
     CheckVLBI

8.  After running "obset", reboot the station computer.
    To reboot, just push the red reset button on the Motorola chassis.
    Alternately, you can go to the console and type: "reboot"
    Or if you are lazy you can do it remotely:
      rcmd reboot gb [while logged in as gbvlbi]

8.5 After the old station computer has finished rebooting (usually takes 
     a few minutes) check that it has the correct project
     and start time for the first project in the queue:
     run "rscreens" (use the "rs" command) and go to menu
     item   OBS/OBS.

9.  Check if we have enough disk packs for the next several runs.
    If not, send message to Juan Cordova at the AOC.
       -- mail to : jcordova@aoc.nrao.edu or vlbatape@aoc.nrao.edu

10. Before each run make a listing of the "sch" file for the operators.
    For example:  
	a2ps -f6.0 -Pops4050 bb240dusch.gb   (compact print)

        larger print: lp -d ops4050 -o cpi=12 bb240dusch.gb
        with "enscript":
            medium: enscript bb240dusch.gb -Pops4050 -f Courier9  
            large:  enscript bb240dusch.gb -Pops4050 -r -f Courier12 (landscape)

11. Bring up Astrid and check that the project code is in the 
    Astrid project list.  If not, ask the Operator to create it.

12. In Astrid, import the astrid scripts for each project.
    These are the ones with "obs00", "obs01", etc in the names;
    also import the scripts for calibrators, for example for a
    recent project BB240DV, import the following files:

       BB240DV_0528+134_pk.turtle
       BB240DV_obs00_pk.turtle
       BB240DV_obs01.turtle

13. After each run remind the operators to send the disk pack to the
    correlator; and check which correlator to send it to --
    usually it goes to Socorro, but sometimes to JIVE or Bonn.

14. After a project has been completed, run the pointing summary,
    if it is at C-band or higher frequency.
    Refer to instructions at the bottom of the web page:
      http://www.gb.nrao.edu/GBT/setups/vlbsetup/pointingsummary.html

15. Move the old projects from the "vlbsetups" web page to the "vlbarc"
    web page.  Note that the projects in "vlbarc" should be in reverse
    time order, i.e., the most recent one at the top.

    Note a python script to move an entry from vlbsetups to vlbarcd:
	~/codelinux_mk5/python/popsetuplist.py

16. Move project files for the completed projects from the
    "obs/" directory to the "obs/oldsched/[projname]/" directory.