$LastChangedDate: 27-Juil-2011 $

# CL_ex_meanLyddane

Lyddane orbit propagation analytical model (mean elements)

## Calling Sequence

       [mean_kep] = CL_ex_meanLyddane(osc_kep [,er,mu,zonals])

## Description

- Computes the mean Keplerian elements mean_kep from the osculating Keplerian elements osc_kep.

- The orbital elements are the following:

- Warnings :

  - This function does not work for inclinations close to the critical inclinations (63.43494882 deg and 116.5650512 deg)

  - This function does not work for eccentricities higher than 0.9

## Parameters

osc_kep:

  Osculating Keplerian elements [sma;ecc;inc;pom;raan;anm] (6xN)

er:

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

mu:

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

zonals:

  (optional) Vector of zonals coefficients J1 to Jn (troncated to J5) to be used (default is %CL_j1jn(1:5)) (Nz x 1)

mean_kep:

  Mean Keplerian elements [sma;ecc;inc;pom;raan;anm] (6xN)

## Authors

- CNES - DCT/SB

## See also

- CL_ex_lyddane

- CL_ex_lyddaneMan

## Bibliography

- 1) CNES - MSLIB FORTRAN 90, Volume E (me_lyddane_mean)

## Examples

    osc_kep_t1 = [42166712 ; 7.9e-3 ; CL_deg2rad([97.2 ; 89 ; 125 ; 0])];
    mean_kep_t1 = CL_ex_meanLyddane(osc_kep_t1)
    // check
    [mean_kep_t2,osc_kep_t2] = CL_ex_lyddane(0,mean_kep_t1,0)