How to simplify GPS Tracks

I use GPSBabel to simplify GPX tracks (remove multiple aligned points, etc), with the following command line:

$ gpsbabel -i gpx -f raw.gpx -x simplify,crosstrack,error=0.005k -x discard,hdop=4 -o gpx -F simplified.gpx

This use the simplify filter of GPSBabel, where the number specified with error= is the error in kilometer (k).

How to reduce/orient pictures

I use ImageMagick to reduce the picture size to something lighter to download, and also to rotate pictures in the good orientation following exif data (you must have a camera that save the camera orientation in exif data to use it)

$ mogrify -resize 800x600 -auto-orient pict-dir/*.JPG

How to add time to hand made Track

journey2web manages images based on their time, correlating with the time of successive points of a gps track.

If you create a track by your own (using viking for example) you'll have to add those time tags by hand, which can be very hard depending on the amount of tracks and trackpoints you have to edit.

One fancier way is to use gpsbabel, simulating a moving speed on your track. If you know your supposed speed, you can build segments of same size, separated by same time interval.

First, interpolate points of the track based on a constant distance:

$ gpsbabel -i gpx -f inputtrack.gpx -x interpolate,distance=1k -o gpx -F distancetrack.gpx

would add a point each kilometer.

Then, date the points, from a start date, increasing each one for a same amount of time.

$ gpsbabel -i gpx -f distancetrack.gpx -x track,faketime=20110915100000+360 -o gpx -F timetrack.gpx

will date each point from 15th of september, year 2011, at 6min interval.

This simulates a speed of 10km per hour.