====== GPS track manipulation ======

Tools:
  * gpsbabel
  * gpxsee
  * viking
  * qmapshack

===== Merge multiple track files =====

  * <code>gpsbabel -i gpx -f track1.gpx -f track2.gpx -o gpx -F merged.gpx</code>
  * For merging automatically a list of files:<code>
l=""; for f in $(ls *.gpx); do l="$l -f $f"; done; echo gpsbabel -i gpx ($l) -o gpx -F merged.gpx;
</code>

===== Format conversion =====

  * <code>gpsbabel -i kml -f file.kml -o gpx -F file.gpx</code>

===== Filters =====

  * remove duplicate waypoints (eg geocaches): ''-x duplicate,location''
  * fix time: ''-x track,move=-1h-1s''
  * remove elements: ''-x nuketypes,waypoints'', ''-x nuketypes,tracks''
  * simplify track: ''-x simplify,crosstrack,error=0.001''
  * pack all tracks:
    * ''-x track,pack''
    * if time is missing, a workaround with QMapShack is to reorder the tracks with drag and drop in the list, select them, right click, ''Combine Tracks'', and then right click on the new project, "Save as GPX 1.1 w/o ext" 
  * crop track: ''-x track,stop=20201231235959'', ''-x track,start=20201231235959''
  * remove waypoints by mouse selection: qmapshack, right click, "Select Items On Map", click and drag, "delete all selected items", right click on file in right panel, save as, gpx