This filter modifies any tracks so that either the distance or the time
between consecutive points is no more than the specified interval. Where
points are missing, the filter fills them in by following a straight
line (actually a great circle) between the adjacent points. You
must specify either the
distance or the time option.
Example 4.5. Using the interpolate filter
This command line reads track.gpx and inserts points wherever two adjacent trackpoints are more than 10 seconds apart:
gpsbabel -i gpx -f track.gpx -x interpolate,time=10 -o gpx -F newtrack.gpx
This command reads track.gpx and inserts points wherever two adjacent trackpoints are more than 15 kilometers apart:
gpsbabel -i gpx -f track.gpx -x interpolate,distance=15k -o gpx -F newtrack.gpx
This command reads track.gpx and inserts points wherever two adjacent trackpoints are more than 2 miles apart:
gpsbabel -i gpx -f track.gpx -x interpolate,distance=2m -o gpx -F newtrack.gpx
Time interval in seconds.
This option specifies the maximum allowable time interval between points in the track. If two points in the track are further apart than this value, new points will be inserted between them.
This value is always specified in units of seconds. Examples: 31, 1.5.
Either this option or the distance must be specified.
Distance interval in miles or kilometers.
This option specifies the maximum allowable distance between points in the track. If two points in the track are further apart than this value, new points will be inserted between them.
This value may be specified in units of miles (3M, 3.5M) or kilometers (5K, 5.7K). If no units are specified, the units are assumed to be miles.
Either this option or the time must be specified.