This filter is used to "fix" unreliable GPS data by discarding points with HDOP and/or VDOP above a specified limit. HDOP and VDOP are measures of the best possible horizontal or vertical precision for a given configuration of GPS satellites.
Example 4.14. Using the discard filter
gpsbabel -i gpx -f in.gpx -x discard,hdop=10,vdop=20,hdopandvdop -o gpx -F out.gpx
Contributed by Tobias Minich.
Suppress waypoints with higher hdop.
This option specifies the maximum allowable Horizontal Dilution of
Precision (HDOP). By default, any point with an HDOP in excess of
this value will be discarded regardless of its VDOP, but see
hdopandvdop
.
Suppress waypoints with higher vdop.
This option specifies the maximum allowable Vertical Dilution of
Precision (VDOP). By default, any point with an VDOP in excess of
this value will be discarded regardless of its HDOP, but see
hdopandvdop
.