sda {trip}

Filter track for speed, distance and angle.

Description

Create a filter index of a track for "bad" points with a combination of speed, distance and angle tests.

Usage

sda(x, smax, ang = c(15, 25), distlim = c(2.5, 5), pre = NULL)

Arguments

x

trip object

smax

maximum speed, in km/h

ang

minimum turning angle/s in degrees

distlim

maximum step lengths in km

pre

include this filter in the removal

Details

This is an independent implementation from that in the package argosfilter by Freitas 2008.

Value

logical vector, with FALSE values where the tests failed

References

Freitas, C., Lydersen, C., Fedak, M. A. and Kovacs, K. M. (2008), A simple new algorithm to filter marine mammal Argos locations. Marine Mammal Science, 24: 315?V325. doi: 10.1111/j.1748-7692.2007.00180.x