Long-term time derivative of inclination (thirdbody perturbation)
[incdot] = CL_op_incdotSsoCirc(mltan, sma [[, inc, mu_b, r_b, inc_b, er, mu, j2, rotr_pla_sun]])
Long-term (that is doubly averaged) time derivative of inclination due to thirdbody perturbation for a circular and Sun-synchronous orbit.
The formula is the result of an analytical calculation assuming a simplified model for the orbit of the perturbing body (circular orbit, constant inclination).
Notes:
- Inclination can be [] or not specified in which case it is recomputed.
- The function could theoretically be used for another body than the Sun, provided the orbit plane (RAAN) rotates as the same angular rate as the perturbing body.
- The default value used for the apparent inclination of the orbit of the perturbing body is the value at J2000 in ECI (23.44 deg). In reality the value is not constant: there is a long-term drift of about -0.014 deg/century and variations of maximum amplitude about 0.005 deg.
Mean local time of the ascending node. [h] (1xN or 1x1)
Mean semi-major axis. [m] (1xN or 1x1)
(optional) Mean inclination. Default: []. [rad] (1xN or 1x1)
(optional) Gravitational constant of perturbing body. Default: %CL_body.Sun.mu. [m^3/s^2] (1x1)
(optional) Distance from central body to perturbing body. Default: %CL_au. [m] (1x1 or 1xN)
(optional) Inclination of orbit of perturbing body. Default: 23.44 deg. [rad] (1x1 or 1xN)
(optional) Equatorial radius. Default: %CL_eqRad. [m] (1x1).
(optional) Gravitational constant. Default: %CL_mu. [m^3/s^2] (1x1)
(optional) Second zonal harmonic (unnormalized). Default: %CL_j1jn(2). [-] (1x1)
(optional) Mean apparent rotation rate of the Sun around the body. Default: %CL_rotrBodySun. [rad/s] (1x1)
Time derivative of inclination. [rad/s] (1xN)