$LastChangedDate: 27-Juil-2011 $

# CL_oe_car2cirEqua

Cartesian to circular equatorial adapted orbital elements

## Calling Sequence

       [cir_equa[,jacob]]=CL_oe_car2cirEqua(pos_car,vel_car[,mu])

## Description

- Converts position and velocity to orbital elements adapted to near-circular near-equatorial orbits. (elliptic orbit only)

  The transformation jacobian is optionally computed.

  See Orbital elements for more details

## Parameters

pos_car:

  position [X;Y;Z] [m] (3xN)

vel_car:

  velocity [Vx;Vy;Vz] [m/s] (3xN)

mu :

  (optional) gravitational constant [m^3/s^2] (default value is %CL_mu)

cir_equa:

  orbital elements adapted to near-circular near-equatorial orbits. [sma;ex;ey;ix;iy;pom+raan+anm] [m,rad] (6xN)

jacob:

  (optional) transformation jacobian d(X,Y,Z,Vx,Vy,Vz)/d(sma,ex,ey,ix,iy,pom+raan+anm) (6x6xN)

## Bibliography

- 1) CNES - MSLIB FORTRAN 90, Volume V (mv_car_cir_equa)

## Authors

- CNES - DCT/SB

## See also

- CL_oe_cirEqua2car

- CL_oe_car2cir

- CL_co_car2sph

- CL_co_car2ell

- CL_oe_car2kep

## Examples

    // Example 1
    pos_car=[-29536113;30329259;-100125];
    vel_car=[-2194;-2141;-8];
    [cirequa,jacob1] = CL_oe_car2cirEqua(pos_car,vel_car);
    [pos_car2,vel_car2,jacob2] = CL_oe_cirEqua2car(cirequa);