distanceFilter: Filter for unrealistic positions within a track based on...
In GeoLight: Analysis of Light Based Geolocator Data

Description Usage Arguments Details Value Author(s)

The filter identifies unrealistic positions. The maximal distance per hour/day can be set corresponding to the particular species.

1 2	distanceFilter(tFirst, tSecond, type, twl, degElevation = -6, distance, units = "hour")

`tFirst`	vector of sunrise/sunset times (e.g. 2008-12-01 08:30).
`tSecond`	vector of of sunrise/sunset times (e.g. 2008-12-01 17:30).
`type`	vector of either 1 or 2, defining `tFirst` as sunrise or sunset respectively.
`twl`	data.frame containing twilights and at least `tFirst`, `tSecond` and `type` (alternatively give each parameter separately).
`degElevation`	sun elevation angle in degrees (e.g. -6 for "civil twilight")
`distance`	the maximal distance in km per `units`. Distances above will be considered as unrealistic.
`units`	the time unite corresponding to the distance. Default is "hour", alternative option is "day".

Note that this type of filter significantly depends on the calibration (degElevation). Especially during equinox periods. In contrast, the (loessFilter) is independent from positions (uses twilight times) and therefore superior.

Logical vector. TRUE means the particular position passed the filter.

Simeon Lisovski, Fraenzi Korner-Nievergelt

GeoLight documentation built on May 1, 2019, 8 p.m.