Find the delta position from two positions A and B
Source:R/n_EA_E_and_n_EB_E2p_AB_E.R
n_EA_E_and_n_EB_E2p_AB_E.Rd
Given the n-vectors for positions A (n_EA_E
) and B (n_EB_E
), the
output is the delta vector from A to B (p_AB_E
).
Usage
n_EA_E_and_n_EB_E2p_AB_E(
n_EA_E,
n_EB_E,
z_EA = 0,
z_EB = 0,
a = 6378137,
f = 1/298.257223563
)
Arguments
- n_EA_E
n-vector of position A, decomposed in E (3x1 vector) (no unit)
- n_EB_E
n-vector of position B, decomposed in E (3x1 vector) (no unit)
- z_EA
Depth of system A, relative to the ellipsoid (z_EA = -height) (m, default 0)
- z_EB
Depth of system B, relative to the ellipsoid (z_EB = -height) (m, default 0)
- a
Semi-major axis of the Earth ellipsoid (m, default [WGS-84] 6378137)
- f
Flattening of the Earth ellipsoid (no unit, default [WGS-84] 1/298.257223563)
Details
The calculation is exact, taking the ellipticity of the Earth into account.
It is also nonsingular as both n-vector and p-vector are nonsingular
(except for the center of the Earth).
The default ellipsoid model used is WGS-84, but other ellipsoids (or spheres) might be specified
via the optional parameters a
and f
.
References
Kenneth Gade A Nonsingular Horizontal Position Representation. The Journal of Navigation, Volume 63, Issue 03, pp 395-417, July 2010.
Examples
lat_EA <- rad(1); lon_EA <- rad(2); z_EA <- 3
lat_EB <- rad(4); lon_EB <- rad(5); z_EB <- 6
n_EA_E <- lat_lon2n_E(lat_EA, lon_EA)
n_EB_E <- lat_lon2n_E(lat_EB, lon_EB)
n_EA_E_and_n_EB_E2p_AB_E(n_EA_E, n_EB_E, z_EA, z_EB)
#> [1] -34798.44 331985.66 331375.96