Projections used in the IDOD project

In the scope of the IDOD project, we have chosen to use the Azimuthal Equidistant Projection of Postel. This projection preserves the distances between certain points and gives the azimuth of all points correctly with respect to the center. You can obtain more information about coordinate system concepts.

In our project, the center of the projection (0, 55°N) has been chosen to reduce deformation in the whole interest area (12°E, 62°N - 10°W, 44°N).

To change the coordinates of a point from a geographic coordinate system to a projected coordinate system (in this case, the Azimuthal Equidistant Projection of Postel) use this mathematical transformation:

Latitude of your point = in radians
Longitude of your point = in radians

x = coordinate x in Postel (meters)
y = coordinate y in Postel (meters)

= 55 (in radians)
= 0 (in radians )
R = 6371000 m (radius of the earth)

= acos ((sin * sin ) + (cos * cos * cos ( - )))

k' = a / sin a

x = R * k' * (cos * sin ( - ))
y = R * k' * (cos * sin ) - (sin * cos * cos ( - ))