Name

CL_ex_secularJ2 — Secular J2 effects orbit propagation

Calling Sequence

   [kep_t2] = CL_ex_secularJ2(t1, kep_t1, t2[,er[,mu[,j2]]]))
   
   

Parameters

t1:

date(s) in CNES julian days of keplerian orbital elements : Same date for all keplerian elements : (1x1) or different date for each keplerian element (1xN)

kep_t1:

keplerian orbital elements (6xN or 6x1)

t2:

dates in CNES julian days (1x1 or 1xM)

kep_t2:

extrapolated keplerian orbital elements (6 x max(N,M))

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

Description

  • Propagation of keplerian orbital elements kep_t1 at dates t2 with secular J2 effects only.

    Secular J2 effects consist of a drift on periapsis argument, right ascension of ascending node and mean anomaly. See CL_op_driftJ2 for more details.

  • Warning : this function works with either t2 scalar and kep_t1 vector (6xN) OR with t2 vector (1xM) and kep_t1 (6x1)

Authors

CNES - DCT/SB

See also

CL_ex_kepler, CL_ex_lyddane, CL_ex_eckHech, CL_op_driftJ2

Examples

// J2 secular extrapolation of one satellite at several dates :
dga = 7070 * 1000;
ecc = 0.001;
inc = CL_deg2rad(98);
pom = CL_deg2rad(90);
gom = 0;
anm = 0;
t1 = 21915;
t2 = t1:0.1:t1+1;
kep_t1=[dga;ecc;inc;pom;gom;anm];
[kep_t2] = CL_ex_secularJ2(t1, kep_t1, t2);

// J2 secular extrapolation of 2 satellites at one date:
t2 = t1+1;
t1=[t1,t1+0.5];
kep_t1=[kep_t1,[dga+100*1000;ecc+0.1;inc;pom;gom;anm]];
[kep_t2] = CL_ex_secularJ2(t1, kep_t1, t2);