CL_co_car2ell

Description

• Converts cartesian coordinates into elliptical ("geodetic") coordinates.

  Elliptical coordinates are longitude, latitude and altitude with respect to some reference ellipsoid.

  The reference ellipsoid is an ellipsoid of revolution around the Z axis. It is then characterized by 2 parameters:

  - semi-major axis of the ellipse obtained as the intersection of the ellipsoid with any plane containing the Z axis,

  - oblateness (or flattening) of this ellipse.

  

• Notes:

  - The transformation jacobian is computed if the corresponding output argument exists.

  - Be careful that the 3rd elliptical coordinate is an altitude and not the distance to the planet center.

Parameters

pos_car :

Position vector in cartesian coordinates [X;Y;Z] [m] (3xN)

er :

(optional) Equatorial radius of reference ellipsoid [m] (default is %CL_eqRad)

obla :

(optional) Oblateness of reference ellipsoid (default is %CL_obla)

pos_ell :

Position vector in elliptical ("geodetic") coordinates [longitude;latitude;alt] [rad,m] (3xN)

jacob :

(optional) Transformation jacobian (3x3xN)

Authors

• CNES - DCT/SB

Bibliography

• 1) Mecanique Spatiale, Cnes - Cepadues Editions, Tome I, section 3.2.3 (Les reperes de l'espace et du temps, Relations entre les coordonnees)

• 2) CNES - MSLIB FORTRAN 90, Volume T (mt_car_geod)

See also

• CL_co_ell2car

• CL_co_car2sph

Examples

// Example 1 pos_car = [4637885.347; 121344.608; 4362452.869]; [pos_ell] = CL_co_car2ell(pos_car); // Example 2 : consistency test pos_car = [4637885.347; 121344.608; 4362452.869]; [pos_ell,jacob1] = CL_co_car2ell(pos_car); [pos_car2,jacob2] = CL_co_ell2car(pos_ell); M = jacob1*jacob2; // identity matrix