*** NOTE:
    VAX-VMS users can find available software from 
    UCLASP::DISK$SCRATCH:[PDSUSER.SOFTWARE].

               ****** PVROT USER'S GUIDE *******

PVROT is a program written by PDS which will read the Pioneer Venus
Orbiter (PVO) high resolution magnetometer data from the Magnetometer /
Electric Field Detector / Ephemeris data CDROMs (PV01_00xx) and rotates
the data from spacecraft into Venus Solar Orbital (VSO) coordinates
and output an ASCII data file.

Input:  High resolution OMAG and EPHEM data read directly from CDROM
Output: ASCII or IGPP Flatfile data files
Supported Platforms:
        Sun (Sun O/S and Solaris) workstations
        HP Workstations (HPUX)
        VAX VMS 5.x systems
        IBM style PC's in a DOS window

The user directs the program to produce the desired output by commanding
the software with options given on the command line. All command line
options may be shortened to the minimum number of characters required to
uniquely identify the option.

Usage:  pvrot cd_location=XXX orbit=XXX file_type=XXX outfile=XXX host=XXX

Options: 
      cd_location: The location or path to the top directory of the CDROM.

                   On a UNIX system this might be something like
                        "/cdrom/pv01_0012"
                   On a DOS system this might be something like "D:\"
                   On a VMS system this might be something like "DUA0:"

       orbit:      The orbit number of the data to be rotated into VSO
                   coordinates.

       outfile:    The name of the output data file (i.e. mydata.asc). If
                   the output file type is flatfile, do not include an FFD
                   extension (i.e. outfile=mydata , NOT outfile=mydata.ffd)

       file_type:  The type of output data file to create.
                   Valid options are ASCII, FLATFILE, FLOW.
                      ASCII produces an ASCII data file
                      FLATFILE produces an IGPP flatfile

       host:       The type of platform on which the software is being run.
                   Valid: SUN, HP, VAX, PC


-------------------------------------------------------------------
UNIX Usage Examples - 
-------------------------------------------------------------------

pvrot.sun cd=/cdrom orb=2703 out=orb2703.asc

   This example uses the default output type of ASCII and the default host
   of SUN on a Sun O/S system to rotate and extract data from orbit 2703.

pvrot.sol cd=/cdrom/PV01_0044 orb=2703 out=orb2703 file=flat

   This example creates an IGPP Flatfile (file=flat) on a Sun Solaris system
   for orbit 2703.

pvrot.hp cd=/cdrom/PV01_0044 orb=2703 out=orb2703.asc host=hp

   This example creates an ASCII file on an HP workstation for orbit 2703.

-------------------------------------------------------------------
DOS Usage Examples - 
-------------------------------------------------------------------

pvrot.exe cd="D:\" orb=2703 out=orb2703.asc host=PC

   This example uses the default output type of ASCII and the host
   of PC on a DOS system to rotate and extract data from orbit 2703.

pvrot.exe cd="D:\" orb=2703 out=orb2703 file=flat host=PC

   This example creates an IGPP Flatfile (file=flat) on a DOS system
   for orbit 2703.

-------------------------------------------------------------------
VMS Usage Examples - Running from a hard disk
-------------------------------------------------------------------
Let's assume for this example that PVROT has been installed on your system
at DISK$SOFT:[PDS.SOFTWARE.EXIES] and that the CDROM device on the system
is called DISK$CDROM:

To get the VMS system to accept command line input to the program, the
executable must be pointed to by a logical variable which you can define
using the following command:

PVROT :== $DISK$SOFT:[PDS.SOFTWARE.EXIES]PVROT.EXE


pvrot cd=DISK$CDROM: orb=2703 out=orb2703.asc host=vax

   This example uses the logical variable PVROT to extract data from orbit
   2703 to an ASCII file located in the directory from which the command
   was issued.

pvrot cd=DISK$CDROM: orb=2703 out=[-.DATA]orb2703.asc host=vax

   This example uses the logical variable PVROT to extract data from orbit
   2703 to an ASCII file located in the directory DATA which is located back
   one directory level from where the command was issued.


Normal termination of PVROT on VMS machines will return a traceback error
message which has the appearance:

*************************
End-of-File reached on Mag data file
No Ephemeris data file read errors detected

Normal termination - No errors detected

%SYSTEM-F-ACCVIO, access violation, reason mask=01, virtual address=78617600,
PC=000076F5, PSL=03C00000
%TRACE-F-TRACEBACK, symbolic stack dump follows
module name     routine name                     line       rel PC    abs PC

L__MAIN         gcc2_compiled.                   1538      00000019  000076F5
                                                           803074B2  803074B2
                                                           00053699  00053699
PVROT           main                                       00000797  00005709
************************** 

As long as the line that says "Normal termination - No errors detected"
appears, the program has completed without error. The error message that
follows has to do with compiler incompatibilities between the various
systems.