| navigation.hac {echogram} | R Documentation |
Compute bearing, navigated distance and speed
Description
This function computes navigation course (bearing), navigated distance, time diference and navigation speed between GPS fixes in position data imported from an HAC file.
Usage
navigation.hac(pos)
Arguments
pos |
geographic position data from an HAC file, as imported with |
Details
The bearing and navigated distance are computed with functions bearingRhumb and distVincentyEllipsoid from package geosphere. This function is intended to be called inside read.echogram, rather than being used directly.
Value
A data frame with seven variables:
time.cpu |
date and time from the computer CPU during data acquisition. |
lon |
longitudes. |
lat |
latitudes. |
bearing |
navigation course between two consecutive GPS fixes. |
navdist |
navigated distance between two consecutive GPS fixes. |
time.dif |
time difference between two consecutive GPS fixes. |
navspeed |
navigation speed between two consecutive GPS fixes. |
Author(s)
Héctor Villalobos
See Also
position.hac, bearingRhumb, distVincentyEllipsoid.
Examples
hacfile <- system.file("hac", "D20150510-T202221.hac", package="echogram")
pos <- position.hac( hacfile )
pos
pos2 <- navigation.hac(pos)
pos2