NAME

       earthtrack - Combine xplanet and predict

SYNOPSIS

        earthtrack  [  -h <predictservername> ] [ -p <proj> ] [ -x <arguments for xplanet> ] [ -u <screen update
       interval> ] [ -o <send output to image file (default: /tmp/xplanet.png)>  ]  [  -c  <satellite>  ]  [  -C
       <satellite> ]

OPERATION

       "earthtrack"  uses "xplanet" to produce an orthographic image of the earth upon which satellite names are
       placed over their  respective  sub-satellite  points.   The  globe  can  be  centered  either  over  your
       groundstation  location  (default),  or  over  the  location any satellite being tracked by PREDICT.  The
       second method allows you to "fly with the satellite" as it circles the globe.  The map is  updated  every
       20  seconds.   By  default,  "earthtrack"  connects  to the PREDICT server running on "localhost".  These
       defaults may be overridden through several command-line switches.

       The -h switch allows a different PREDICT server name to  be  specified.   The  -x  switch  option  allows
       additional  command-line  parameters to be passed to xplanet through earthtrack.  (Note that the argument
       that follows the -x switch must be enclosed in "quotes".)  The -u switch allows a  different  map  update
       interval to be specified, and the -c switch allows the map to be centered on a specific satellite.

       For example:

            earthtrack -c ISS -u 15 -h predictserver.org

       allows  earthtrack to invoke "xearth" as a display, centering the map on the location of satellite "ISS",
       using host "predictserver.org" as the host running PREDICT in server mode.  The satellite name  specified
       must  be  the  same as PREDICT displays in Multi-Tracking mode.  If a space appears in the name, then the
       entire name must be enclosed in double quotes.

       "xplanet" uses highly detailed photo-realistic maps of the world available from a variety of  sources  to
       produce  spectacular views of the earth.  For example, if an uppercase -C is used rather than a lowercase
       -c for the map center switch, such as in the following example:

            earthtrack -C ISS

       the map is not only centered on the location of the ISS, but the map is also zoomed into an area slightly
       larger than the footprint of the satellite.  A range circle is also drawn on  the  map  to  indicate  the
       actual footprint of the spacecraft at the current time.

       If  a map centered on the groundstation location is desired, then footprint range circles for neighboring
       satellites are drawn on the map.  Range circles are drawn for satellites between 5 minutes prior  to  AOS
       through  the  point  of  LOS.  Such a display may be created simply by executing "earthtrack" without any
       switches:

            earthtrack

       or with the -h switch to identify the remote host running PREDICT in server mode:

            earthtrack -h predictserver.org

       If the satellite being tracked is in sunlight, then the satellite name and range circle are displayed  in
       white.   If  the  satellite  is  in darkness, then the color blue is used.  If the satellite is optically
       visible to the groundstation, then yellow is used.

       "earthtrack" may also be used to generate graphics  files  for  use  in  web  server  environments.   For
       example:

            earthtrack2 -c ISS -x "-geometry 800x600 -output graphic.png"

       will invoke "xplanet" to produce an 800x600 PNG image of the world centered on the sub-satellite point of
       the  ISS  with  a  name  of  "graphic.png".   This  feature,  along with capabilities demonstrated in the
       ~/predict/clients/samples directory, can be used to develop satellite  tracking  and  orbital  prediction
       content for a web server.

       "earthtrack" exits when its connection to the PREDICT server is broken, such as would occur if PREDICT is
       terminated  while  "earthtrack"  is still running.  The application may be run as background processes by
       placing an ampersand (&) at the end of the command line.

       This version includes a -o switch to send the output to the  file  /tmp/xplanet.png  instead  of  to  the
       screen.

       For  more  creative  uses  of  PREDICT  and  earthtrack,  see John Heaton, G1YYH's PREDICT and earthtrack
       modification web page at:

            http://voyager.mcc.ac.uk/Predict/

       Happy Tracking!

       73, de John, KD2BD
       June 2003

OPTIONS

               -c <satellite> (center on satellite)
               -C <satellite> (center on satellite and zoom in)
            -h <hostname running predict in server mode>
            -o <output to image file>
            -p <projection>
            -x <command line arguments to pass along to xplanet>
            -u <screen update interval in seconds>

AUTHOR

       This man page was written by A. Maitland Bottoms, AA4HS, for Debian GNU/Linux.

                                                 31 August 2003                                    EARTHTRACK(1)