CL_op_ssoJ2

Description

• Computes orbital parameters (semi major axis, eccentricity or inclination) ensuring sun-synchronicity so that the orbit's ascending node precession rate is equal to the Sun apparent rotation rate rotr_pla_sun.(See equation (1))

  - If type_output="a", par1 is eccentricity, par2 is inclination and semi major axis is computed (output).

  - If type_output="e", par1 is semi major axis, par2 is inclination and eccentricity is computed (output).

  - If type_output="i", par1 is semi major axis, par2 is eccentricity and inclination is computed (output)

  

Note: %nan is returned when sun-synchronicity is not possible

Parameters

type_output:

String defining the parameter to be computed (output). It can be "a" for semi major axis, "e" for eccentricity or "i" for inclination

par1:

Semi major axis if type_output is "e" or "i" ; eccentricity if type_output is "a" [m] (1xN or 1x1)

par2:

Inclination if type_output is "a" or "e" ; eccentricity if type_output is "i" [rad] (1xN or 1x1)

er:

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

mu:

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

j2:

(optional) Second zonal harmonic term (default is %CL_j1jn(2))

rotr_pla_sun :

(optional) Mean apparent rotation rate of the Sun around the planet (default is %CL_rotrBodySun) (1 x 1)

output:

Semi major axis [m] if type_output is "a" ; eccentricity if type_output is "e" ; inclination [rad] if type_output is "i" (1xN). Output value is %nan if no valid result exists.

Authors

• CNES - DCT/SB

Examples

// Compute inclination for sun-synchronicity sma = 7078.e3; ecc = 0.01; inc = CL_op_ssoJ2 ("i", sma, ecc) // Compute eccentricity for sun-synchronicity sma = 7078.e3; inc = CL_deg2rad(98.15); ecc = CL_op_ssoJ2 ("e", sma, inc) // Compute semi major axis for sun-synchronicity ecc = 0.01; inc = CL_deg2rad(97); sma = CL_op_ssoJ2 ("a", ecc, inc)