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       earthtrack - Combine xplanet and predict


        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> ]


       "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

       allows earthtrack to invoke "xearth" as a display, centering the map on
       the location of satellite "ISS", using host "" 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

       "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:


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

            earthtrack -h

       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:


       Happy Tracking!

       73, de John, KD2BD
       June 2003


               -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>


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

                                31 August 2003