prefilter: Prepare Argos data for fitting a ctrw model

In ianjonsen/ctrw: a Continuous-Time Random Walk state-space model to filter Argos Least Squares or Kalman Filter location data

Description

prefilter() (1) determines Argos data type (LS or KF); (2) converts dates to POSIXt; identifies observations with duplicate dates; (3) orders observations in time; (4) converts longitudes from 0,360 to -180,180; (5) projects lonlat coords to mercator x,y coords (in km); (6) adds location error multiplication factors based on Argos location class (for type LS); and (7) uses a loess smooth to identify potential outlier locations (by distance only) to be ignored when fitting the ctrw model

Usage

prefilter(d, span = 0.01, min.dt = 0, min.dist = 100,
  time.gap = NULL)

Arguments

d	input data - must have 5 (LS), or 8 (KF) columns (see details)
span	degree of loess smoothing (range: 0 - 1) to identify potential outliers
min.dt	minimum allowable time difference between observations; dt < min.dt will be ignored by the SSM
min.dist	minimum distance from track to define potential outlier locations
time.gap	not currently implemented

Details

Internal function

ianjonsen/ctrw documentation built on July 7, 2019, 7:30 p.m.