Name

CL_co_ell2car — Elliptical to cartesien coordinates

Calling Sequence

   [pos_car[,jacob]] = CL_co_ell2car(pos_ell[,er[,obl]])
   
   

Description

  • Given a set of elliptical (or geodetic if planet is earth) coordinates (pos_ell), they are transformed into cartesien coordinates (pos_car)using the given ellipsoid semi-major axis and oblateness.

    If no optionnal arguments are passed, defaults are the earth ellipsoid semi-major axis(equatorial radius) and oblateness.

    Transformation jacobian is optionnally computed.

  • Elliptical (geodetic) latitude is determined by the angle between the normal of the ellipsoid and the plane of the equator, whereas spherical (geocentric) latitude is determined around the centre :

    Warning : pos_ell contains longitude, elliptical latitude, and elliptical altitude (whereas in spherical coordinates it is longitude, spherical latitude and distance to center

  • Last update : 27/6/2008

Parameters

pos_ell :

[lon;lat;alt] position in elliptical (or geodetic) coordinates vector [rad],[m](3xN)

er :

(optional) reference ellipsoid semi-major axis (default is earth equatorial radius %CL_eqRad) [m]

obl :

(optional) reference ellipsoid oblateness (default is earth oblateness %CL_obla)

pos_car :

[x;y;z] position cartesien coordinates vector (in terrestrial frame) [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 coordonnées)

2 CNES - MSLIB FORTRAN 90, Volume T (mt_geod_car)

See also

CL_co_car2ell, CL_co_sph2car, CL_co_car2sph

Examples

// Example 1 :
pos_ell = [ CL_deg2rad(12.125) ; CL_deg2rad(108.2) ; 110.0];
[pos_car,jacob1] = CL_co_ell2car(pos_ell);