polar2Projected: Polar to cartesian coordinates conversion

In lidaRtRee: Forest Analysis with Airborne Laser Scanning (LiDAR) Data

Polar to cartesian coordinates conversion

Description

Computes projected coordinates (Easting, Northing, Altitude) from polar coordinates (Azimuth, Slope, Distance) and center position (Easting, Northing, Altitude). Magnetic declination and meridian convergence are optional parameters. In case distance is measured to the border of objects (e.g. trees), the diameter can be added to compute the coordinates of object center.

Usage

polar2Projected(
  x,
  y,
  z = 0,
  azimuth,
  dist,
  slope = 0,
  declination = 0,
  convergence = 0,
  diameter = 0
)

Arguments

x	vector. easting coordinates of centers in meter
y	vector. northing coordinates of centers in meter
z	vector. altitudes of centers in meters
azimuth	vector. azimuth values from centers in radian
dist	vector. distances between centers and objects in meter
slope	vector. slope values from centers in radian
declination	vector. magnetic declination values in radian
convergence	vector. meridian convergence values in radian
diameter	vector. diameters in meter (e.g. in case a radius should be added to the distance)

Value

A data.frame with easting, northing and altitude coordinates, and horizontal distance from centers to objects centers

See Also

plot_tree_inventory for tree inventory display

Examples

# create data.frame of trees with polar coordinates and diameters
trees <- data.frame(
  x = rep(c(0, 10), each = 2),
  y = rep(c(0, 10), each = 2),
  z = rep(c(0, 2), each = 2),
  azimuth = rep(c(0, pi / 3)),
  dist = rep(c(2, 4)),
  slope = rep(c(0, pi / 6)),
  diameter.cm = c(15, 20, 25, 30)
)
trees

# compute projected coordinates
polar2Projected(trees$x, trees$y, trees$z, trees$azimuth, trees$dist,
  trees$slope,
  declination = 0.03, convergence = 0.02, trees$diameter.cm / 100
)

lidaRtRee documentation built on April 3, 2025, 10:29 p.m.