Name

CL_op_driftJ2 — Drift of orbital elements due to J2

Calling Sequence

   [drift_pom,drift_gom,drift_M[,dpomdaei[,dgomdaei[,dMdaei]]]] = CL_op_driftJ2(sma,ecc,inc[,er[,mu[,j2]]])
   
   

Description

  • Computes the 'secular drift' (delta_pom,delta_gom,delta_M) of keplerian elements (pom,gom,M) for the movement perturbed by the first zonal harmonic J2 and derivatives of these variations with respect to semi major axis, eccentricity and inclination.

    Results are obtained computing the following expressions. On this formula, a is semi majors axis (sma), e is eccentricity (ecc) and i is inclination (inc). drpom, drgom and drM are, respectively, drift of the perigee argument, ascendant node longitude and mean anomaly due to j2. dpomdaei, dgomdaei and dMdaei are derivatives of, respectively, drpom, drgom and drM with respect to a, e and i. n is the mean motion.

  • Last update : 15/5/2008

Parameters

sma:

semi major axis [m] (1xN)

ecc:

eccentricity (1xN)

inc:

inclination [rad] (1xN)

er:

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

mu:

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

j2:

(optional) geopotentiel elliptic factor (second zonal harmonic) (default is %CL_j2)

drift_pom:

drift of the perigee argument [rad/s] (1xN)

drift_gom:

drift of the ascendant node longitude [rad/s] (1xN)

drift_M:

drift of the mean anomaly [rad/s] (1xN)

dpomdaei:

derivative of drift_pom with respect to sma, ecc and inc (3xN)

dgomdaei:

derivative of drift_gom with respect to sma, ecc and inc (3xN)

dMdaei:

derivative of drift_M with respect to sma, ecc and inc (3xN)

Bibliography

1 CNES - MSLIB FORTRAN 90, Volume E (me_deriv_secul_J2)

2 AM_varj2d.F (AMLIB) by O. Defonte, 14/2/1995 (Le mouvement du satellite, Conferences et exercices de Mecanique Spatiale, Toulouse 1983, Cepadues Editions)

See also

Authors

CNES - DCT/SB

Examples

sma=[%CL_eqRad+350000;%CL_eqRad+700000];
ecc=[0.001;0.001];
inc=CL_deg2rad([51.6;51.6]);
[drift_pom,drift_gom,drift_M]=CL_op_driftJ2(sma,ecc,inc)