Trigonometry will work for projected coordinate systems like UTM:
Try this:
# number of points
n = 30
# reference location
ref.pt = cbind(1,2)
# generate some random directions
# This can be your list of your bearings converted to radians
dir - runif(n,0,2*pi )
# generate some random distances
# This can be your list of distances in map units (e.g. m)
dist - runif(n,0.5,10)
#empty matrix for coordinates
coords.mat = cbind(rep(0,n),rep(0,n))
#using trigonometry to calculate object location
for (i in 1:n){
coords.mat[i,1] = ref.pt[1]+(sin(dir[i])*dist[i])
coords.mat[i,2] = ref.pt[2]+(cos(dir[i])*dist[i])
}
plot (coords.mat)
points(ref.pt,col=2)
Best,
Tammy
On Wed, Apr 4, 2012 at 11:02 PM, Ivailo ubuntero.9...@gmail.com wrote:
Der fellow R-users,
I have several sampling sites and in each site the starting plot
(i.e. the first one that have been sampled) is georeferenced with a
GPS but the following ones are just described by their distance and
bearing in relation to the previous one.
Is there a quick way to calculate (by using some of the spatial
R-packages) the geographic coordinates of the sapling plots at each
location that have not been explicitly georeferenced?
Cheers,
Ivailo
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