uwacan.positional.shift_position

shift_position(lat, lon, distance, bearing)

Shifts a position given by latitude and longitude by a certain distance and bearing.

The implementation is based on spherical trigonometry, with internal conversions to geocentric coordinates, and using the local radius of the earth. This is expressed as

\[\begin{split}φ_2 &= \arcsin(\sin(φ_1) ⋅ \cos(δ) + \cos(φ_1) ⋅ \sin(δ) ⋅ \cos(θ)) \\ λ_2 &= λ_1 + \arctan(\frac{\sin(θ) ⋅ \sin(δ) ⋅ \cos(φ_1)}{\cos(δ) - \sin(φ_1) ⋅ \sin(φ_2)})\end{split}\]

where: φ is latitude, λ is longitude, θ is the bearing (clockwise from north), δ is the angular distance d/R; d being the distance traveled, R the earth’s radius.

Parameters:

latfloat

Latitude of the initial position in degrees.

lonfloat

Longitude of the initial position in degrees.

distancefloat

Distance to move from the initial position in meters.

bearingfloat

Direction to move from the initial position in degrees.

Returns:

new_latfloat

Latitude of the new position in degrees.

new_lonfloat

Longitude of the new position in degrees.