CL_dsp_kepCovPropa

Description

• This function is deprecated.

  Replacement function: CL_ex_kepler and compute propagated covariance matrix by : cov_t2 = J * CL_dMult(cov_t1,ones(J)) * J'.

• Performs the propagation of orbital elements and associated covariance matrix using a Keplerian model.

  Given a set of orbital elements kep_t1 and the associated covariance matrix (cov_t1) at time t1, the function computes the orbital elements kep_t2 and the associated covariance matrix (cov_t2) at time t2.

  

• Note:

  This function works for any type of orbit and any type of orbital elements ("kep", "cir", "cireq" or "equin").

Parameters

t1:

Initial time [days] (1x1)

kep_t1:

Keplerian elements at time t1 [sma;ecc;inc;pom;gom;anm] (6x1)

cov_t1:

Covariance matrix at time t1 (6x6)

t2:

Final time(s) [days] (1xN)

mu :

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

kep_t2:

Keplerian elements at t2 [sma;ecc;inc;pom;gom;anm] (6xN)

cov_t2:

Covariance matrix at time t2 (6x6xN)

Authors

• CNES - DCT/SB

See also

• CL_ex_kepler

Examples

// Propagation of covariance matrix (Keplerian elements) t0 = 0; sma = 7.e6; kep0 = [sma; 0.05; 1; 0; 0; 0]; cov0 = diag([100; 1.e-6; 1.e-6; 1.e-6; 1.e-6; 1.e-3].^2); t = t0 + (0 : 300 : 86400) / 86400; [kept, covt] = CL_dsp_kepCovPropa(t0, kep0, cov0, t); scf(); plot(t, sma * matrix(sqrt(covt(6,6,:)), 1, -1)); // Derivation of position covariance matrix in tnw frame [pos, vel, jac] = CL_oe_kep2car(kept); M = CL_fr_tnwMat(pos, vel); covpv = jac * covt * jac'; covploc = M * covpv(1:3,1:3,:) * M'; plot(t, matrix(sqrt(covploc(1,1,:)), 1, -1), "r");