$LastChangedDate: 27-Juil-2011 $

# CL_op_paramsJ2

Orbit properties depending on J2 (mean motion, period, nodal period, ...)

## Calling Sequence

       [par] = CL_op_paramsJ2(type_output,sma,ecc,inc,[er,mu,j2,rotr_pla])
       [par1,par2] = CL_op_paramsJ2([type_output1,type_output2],sma,ecc,inc,[er,mu,j2,rotr_pla])
       [par1,par2,par3] = CL_op_paramsJ2([type_output1,type_output2 type_output3],sma,ecc,inc,[er,mu,j2,rotr_pla])

## Description

- Computes quantities related to the mean motion taking the effect of J2 into account.

  type_output can be :

  - 'mm' : mean motion

  - 'per' : period (from periapsis to the next one)

  - 'nodper' : nodal period (from ascending node to the next one)

  - 'lgap' : gap in longitude between 2 consecutive ground tracks

## Parameters

type_output :

  Name(s) of the quantities to be computed. Possible names are: 'mm','per','nodper','lgap' (1 x Noutput)

sma:

  semi major axis [m] (1xN)

ecc:

  eccentricity (1xN)

inc:

  inclination [rad] (1xN)

er:

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

mu:

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

j2:

  (optional) zonal coefficient (second zonal harmonic) (default is %CL_j2)

rotr_pla:

  (optional) rotation rate of the planet (default is %CL_rotrEarth)

par:

  mean motion, period, nodal period or longitude gap between 2 ground tracks [rad/s,s,s,rad] (1xN)

## Authors

- CNES - DCT/SB

## See also

- CL_kp_params

## Examples

    // Longitude gap between 2 consecutive ground tracks :
    sma = 7078.e3 ;
    ecc = 0.001 ;
    inc = CL_deg2rad(98);
    [lgap] = CL_op_paramsJ2('lgap',sma,ecc,inc)

    // Mean motion and nodal period
    sma = 7078.e3 ;
    ecc = 0.001 ;
    inc = CL_deg2rad(98);
    [mm,nodper] = CL_op_paramsJ2(['mm' 'nodper'],sma,ecc,inc)