Voyager In Space

 

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VOYAGER

Voyager LECP Data Analysis Handbook

 

Ground Processing of Voyager Data

 

IP address for the Fundamental Technologies VAX computer KULECP: 192.168.33.38

 

User logon:
Password:

 

Command Explanation/Comments
$lecpprod Gives access to the directory containing the BigRun program.
$set def KULECP$DKB500:[voyager.v105.new_files]

  or

$set def KULECP$DKB500:[voyager.v205.newfiles]

 Gives access to most recent Voyager 1 data downloaded.

or

Gives access to  most recent Voyager 2 data downloaded.

Look to see the date of the most recent file.  New data will be collected through FTP.
$FTP FTP activates the FTP ability of the vaxes.
FTP>hurlbut.jhuapl.edu Hurlbut is the name of the APL computer from which we get the data; this command tells the FT vax computer where to connect.

HURLBUT.JHUAPL.EDU> login
   Foreign username: anonymous
   Password:

 Password is your email address.

HURLBUT.JHUAPL.EDU> cd pub
HURLBUT.JHUAPL.EDU> cd voyager
HURLBUT.JHUAPL.EDU> cd mrt

 Hurlbut is a unix machine, so while we are on this system all commands will be unix commands.

HURLBUT.JHUAPL.EDU> binary

All files will be in binary format; the system must be told so the files are downloaded properly. 
The file structure for files on this system will be VR#YYDOY.ZIP
     The V means it is a Voyager file.
     The # will be either a 1 or a 2, signifying which spacecraft the data is from.
 Scan the files for the most recent date from FT files.  Retrieve all files after that date dealing with that satellite.
HURLBUT.JHUAPL.EDU> mget File name or partial file name using wildcards for the rest.  For example, VR1052**.Zip will retrieve all Voyager 1 files from the 200th day of the year to the 299th day of the year.
HURLBUT.JHUAPL.EDU> exit Exit from the APL unix machine once all files needed have been transferred.
$edit/edt un.com The file un.com contains a list of commands that will unzip multiple files at once. To change what files are being unzipped edit un.com.

*ch

ch changes the editor so you can edit multiple lines at once.
$unzip filename1.zip;#
$unzip filename2.zip;#
etc.		 For each file that you wish to unzip put in the following:
$unzip filename.zip;#
where filename is the name of the file and # is the version number.
  ctrl z will bring you out of the multiple line edit mode.
*exit Exit will save any changes and leave the edit mode  (use quit to exit without saving).
$@un @un runs all the commands within the file un.com.
  The files are at this point all data on a single line with no carriage returns. To be able to use these files, the attributes,  record format and logical record length must be changed.
$edit/edt chfat.com Chfat.com contains commands to change multiple file attributes at once.
*ch  

$set file attributes=(rfm:var, lrl=968) filename1.mrt;#
$set file attributes=(rfm:var, lrl=968) filename2.mrt;#
etc.

 For each file that you unzipped you now want to set the commands to change their attributes.
*exit  
$@chfat All files are now in the correct format and ready to have BFH run upon them.

$set host KUSPA1

This provides access to another computer with an older operating system which is necessary for BFH to run.
Username:
Password:		 You can use the same username and password that you used originally.

$set def KULECP$DKB500:[voyager.v105.New_files]

Sets the new computer into the directory containing the files that were just set up for it.
$run BFH BFH stands for Binary File Handler.

BFH> open file1.mrt;

 File1 is the first file you wish to work on.  Each file must be done individually. 
 BFH is designed to help get rid of the junk before and after the actual good data.  This requires more user input than any other part of the process.
BFH> look file1.mrt; 20 We are telling the program to show the first 20 lines of the file.  In actuality, though, this can be any number and you may need to change the number to find the best data.
 Look over the data that is shown to find the first good series of time.


In this example the best data begins at line 4; all data before that has time that is not in the correct order, and the year 3801 (meaning 2001) is incorrect. So the user should make note that the best time starts at line 4.
BFH> Map file1.mrt
       Option: v
       Option:		 The map function will run the entire file.  Option v  means verbose, thus showing each line as it is read.  There is no necessary second option.
 User must scroll up to examine the last bits of data.

In this case the last line of good data is line 1739. User makes note of this.
BFH>Rewind
      Filename: file1.mrt		 Rewind sets the file back to the beginning.
BFH>open newfile.mrt In this instance you are creating a new file, where the good data will be placed. The file name is the same name as the file already open, just remove the r, so you have: V#YYDOY.MRT, where # is 1 or 2 depending on which satellite you are dealing with.
BFH> copy file1.mrt newfile.mrt
     Outfile start {<CR>, T, F=, R=}:
     Infile start {<CR>, T, F=, R=}: R = #

Infile stop {<CR>, EOF, EOT, . . . }: R= #

Monitor copy process? Y (Yes) or N (No): Y

...where # is the first good starting number; in our example it would be 4.
 ...where # is the number of the last line of good data.  In this example it would be 1739.
At this point the program will copy all of the data between those two lines into the new file.
This process will have to be run on each file that was unzipped.
BFH>exit Exits BFH

For Voyager 1:

  $assign kulecp$dkb500:[voyager.v105] vger$in

  $assign kulecp$dkb500:[voyager.v105] vger$out

 Sets kulecp$dkb500:[voyager.v105] as the directory holding the source files.
Sets kulecp$dkb500:[voyager.v105] as the directory to place the finished files.

For Voyager 2:

 

  $assign kulecp$dkb500:[voyager.v205] vger$in

  $assign kulecp$dkb500:[voyager.v205] vger$out

 Sets kulecp$dkb500:[voyager.v205] as the directory holding the source files.
Sets kulecp$dkb500:[voyager.v205] as the directory to place the finished files

@big_run

This runs the data and returns filtered data.  We use this primarily for research purposes.

@big_run_nf

 This runs the data and returns unfiltered data.  This is useful to track down problems in the data itself or in the satellite.
 

All csv files are put into a directory that is set automatically at login, called VGER$LIST.  Auxiliary files are sent to a directory called VGER$MAP, also set at login.  These are set by the file login.com, which can be changed although it is best to leave it be.
$set def kulecp$dkb500:[voyager.v105] This drive has some command files which should be used to transfer the files that have been produced from the vaxes and to \\black\from_vaxes\voyager.  From here the files can be moved to the archives.
$edit/edt fat_send.com  
*ch When editing these command files,  change only the names of the files are being sent.

$SET VERIFY
$assign sys$input sys$command
$ftp/user=ftdata/password=ftecsftp 192.168.33.6
BINARY
BLOCK
cd voyager
cd fat
mkdir v105
cd v105
send v105001f.fat;1
send v105069f.fat;1
send v105139f.fat;1
send v105181f.fat;1
send v105222f.fat;1
send v105001g.fat;1
send v105069g.fat;1
send v105139g.fat;1
send v105181g.fat;1
send v105222g.fat;1
exit

 So for this file, only the files listed after “send” should be changed, maintaining the current structure of the files.  Be sure only to list  files with the .fat extension.
*exit Ctrl + z gets you out of multiple line edit mode.

$@ fat_send

 At this point all the files with the .fat extension have been sent.  Move on to the next file.
$edit/edt lnx_send Change the files after the “send” so that they are the files that have been produced; only files ending in the lnx extension should be listed.
$@lnx_send  

$edit/edt mrt_send

 Change the files after the “send” so that they are the files that have been produced; only files ending in the .mrt extension should be listed.

$@mrt_send

  

$edit/edt scn_send

 Change the files after the “send” so that they are the files that have been produced; only files ending in the .scn extension should be listed

@scn_send

 At this point you are done with the vaxes.  The files can be found at \\black\from_vaxes\voyager.  Simply go to this location and move the files to the archives in the appropriate folders.

 

 

Return to Voyager LECP Data Analysis Handbook Table of Contents.
Return to Fundamental Technologies Home Page.


Updated 8/9/19, Cameron Crane

VOYAGER 1 ELAPSED TIME

--:--:--:--
Days: Hours: Minutes: Seconds

*Since official launch
September 5, 1977, 12:56:00:00 UTC

VOYAGER 2 ELAPSED TIME

--:--:--:--
Days: Hours: Minutes: Seconds

*Since official launch
August 20, 1977, 14:29:00:00 UTC

QUICK FACTS

Manufacturer: Voyagers 1 and 2 were built in the Jet Propulsion Laboratory in Southern California.

Mission Duration: 40+ years have elapsed for both Voyager 1 and Voyager 2 (both are ongoing).

Destination: Their original destinations were Saturn and Jupiter. Their current destination is interstellar space.