PDS_VERSION_ID     = PDS3
RECORD_TYPE        = STREAM
OBJECT             = TEXT
  PUBLICATION_DATE = 1999-12-06
  NOTE             = "Description of MPROF software provided with the
    MGS MOLA archive volumes"
END_OBJECT         = TEXT
END

FILES IN THIS DIRECTORY
-----------------------

MPRFINFO.TXT - The file you are reading.

MPROF.PRO    - IDL script to plot MOLA PEDR elevation profiles


MPROF SOFTWARE FOR MGS MOLA ARCHIVE VOLUMES
-------------------------------------------

MPROF is a script written in IDL to plot elevation profiles using MOLA
PEDR data. To use this script, the user must already have IDL
installed. IDL is commercial software produced by Research Systems, 2995
Wilderness Place, Boulder, Colorado 80301, phone 303-786-9900, email
info@rsinc.com. The Research Systems World-Wide Web site is
http://www.rsinc.com.

This version of MPROF is intended to run on either PC/Windows 95
platforms or Sun/UNIX platforms. MOLA data products are generated on
UNIX machines using so-called "big-endian" byte ordering.  The script
detects the byte order of the machine on which it runs.  If it detects a
little-endian machine (such as a PC), it uses the IDL function
SWAP_ENDIAN to correct the byte order of data read from the PEDR file.
MOLA volumes MGSL_0001 and MGSL_0002 had an earlier version of MPROF
that did not detect byte order, and hence had separate versions for
UNIX and PC machines.

At the beginning of the Mapping Phase of the MGS mission, PEDRs began to
be aggregated by day instead of by orbit as they had been in the Cruise
and Orbit Insertion phases. Thus one Mapping Phase PEDR contains data
from a variable number of orbits.  MPROF was written to operate on PEDR
files that contain only one orbit's worth of data. A Mapping Phase PEDR
must first be broken down into separate orbits before MPROF can be used
to plot the data. The IDL script SPLITORB is provided on this volume to
split a PEDR into separate orbits.

To start the application, at the IDL prompt type as shown below:

   IDL> MPROF, n, directory='dir/'

where n is an orbit number and dir is a directory containing PEDRs.  End
the directory with the appropriate character for your operating system;
e.g. \ for a PC or / for UNIX.

Alternatively, you may edit MPROF.PRO to insert a default directory
according to the instructions in the script. Then the script may be
invoked as:

   IDL> MPROF, n

Finally, you may also specify the size of the window in which IDL displays
the data with the optional keywords WIDTH and HEIGHT. For example:

   IDL> MPROF, n, width=1000, height=500

MPROF will then graph the profile for the selected file. The
longitudes (east) of the end points and the point of maximum latitude
are also displayed.

To zoom in on a portion of the profile, hold down the left mouse
button and drag the mouse. This will draw a box which you can use to
enclose the data you wish to plot. Once your box has been sized to fit
your region of interest, release the left mouse button and MPROF will
plot the area.  This can be repeated.  To go back to a plot of the
entire PEDR, click the right mouse button once.

After selecting a region of interest, you can create an ascii file
containing the longitude (east), latitude (north), and elevation
(meters) of the selected data points by clicking the middle mouse
button once. (Note: on PC/Windows machines that do not have a middle
mouse button, you can simulate this action by holding down the Control
key while clicking the left mouse button.) The ascii file thus created
is called MPxxxxxn.OUT, where xxxxx is the orbit number and n
represents the nth file to be created. The first line of the file
lists the number of output data points and the orbit number, and the
second line contains column headings. The remaining lines are data
points. At the same time this file is created, a Postscript file
containing the plot itself is created in MPxxxxxn.PS. If files already
exist with these names they are overwritten.

To quit or select a new PEDR file, click the right mouse button twice.
That will take you back to the starting PEDR data file choices
panel. Then click CANCEL with the left mouse button once to quit
MPROF. To select another file to plot, double click the selected file
icon with with the left mouse button.

MPROF was written by C. David Brown, Washington University, St.  Louis,
Missouri, email dbrown@geoid.wustl.edu. It was modified for this PDS
archive volume by Judd Bowman, PDS Geosciences Node, Washington
University, St. Louis, Missouri, geosci@wunder.wustl.edu.