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* xsnd (examine soundings) utility *
* version 2.0                      *
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The xsnd (examine soundings) utility was created to provide a useful tool for
visually inspecting sounding data (from the surface to 100 hPa) and for manually
editting the QC flags within that sounding data.

This program was originally developed by Patrick Haertel within Dr. Richard H.
Johnson's research group at Colorado State University with NASA funding.  It has
been modified and improved since then by Rick Taft and Paul Ciesielski, both
members of the Dr. Johnson's research group at CSU.

The xsnd tool is written in Tcl/Tk, a simple scripting language that simplifies
the process of writing graphical applications and that is available for a
number of computing environments (including UNIX, Windows, and Macs).  This
program was developed, tested, and used on workstations running Linux, but it
should also work (with no or little modification) on Windows PC's or Mac's
(provided that the free Tcl/Tk software has been installed).

Files:
=====
   README        this readme file
   xsnd          the xsnd program (a Tcl/Tk script)
   skewt-s.gif   "small" resolution skewT image
   skewt-m.gif   "medium" resolution skewT image
   skewt-l.gif   "large" resolution skewT image
   sample.dat    a sample sounding file containing 3 soundings

Installation:
============
(1)  Download the xsnd package (xsnd.tar) to a local directory.

(2)  Extract the files from the xsnd package.
     For example:  tar -xvf xsnd.tar

(3)  Move the 3 GIF images to a convenient location on your computer (such as
     /usr/local/lib/xsnd).

(4)  Edit the global variable "imageDir" in the xsnd script (line 33) to be the
     location chosen in step (3).

(5)  Make sure the xsnd script is executable, and move it to a location that is
     on your Path (such as /usr/local/bin).

Usage:
=====
To run the xsnd program with a sounding datafile called "soundings.dat", type
one of the following at the command line:

      xsnd soundings.dat
   or
      xsnd s soundings.dat
   or
      xsnd m soundings.dat
   or
      xsnd l soundings.dat

The first 2 options run the xsnd program in "small" resolution mode.  The 3rd
option runs xsnd in "medium" resolution mode, and the last option runs it in
"large" resolution mode.

Note that sounding datafile must have the same ASCII format as the provided
sample sounding datafile to work with the provided xsnd program.  However, the
xsnd program can be easily modified to handle other datafile formats if needed.
Also note that the sounding datafile can contain data above 100 hPa, but that
such data values will not be shown in the xsnd program.

Please see the following website for more information about sounding data QC
and the xsnd program:  http://www.eol.ucar.edu/projects/sondeqc/
