Name

CL_mod_precessionMatrix — Precession matrix and rotation vectors (IERS 1996)

Calling Sequence

   [PREC[,OM[,OMP]]] = CL_mod_precessionMatrix(K,KP,KPP[,flag])
   
   

Description

  • Calculate precession matrix, rotation vector and its time derivatives. Matrix from mean equator/equinox at date t to mean equator/equinox at J2000.

    if P0 is the pole of J2000 equator, and P is the pole of the equator at date t; if G0 is the equinox of J2000 and G is the equinox at date t:

    zetaa : angle between the meridians (pole P0) P0-P and P0-G0

    thetaa: angle between the equateur J2000 and the equateur t

    za : angle between the meridians (pole P) P-P0 and P-G

  • Last update : 27/6/2008

Parameters

K :

[zetaa;tetaa;za] (3xN)

KP :

[zetaap;tetaap;zap] (3xN)

KPP :

[zetaapp;tetaapp;zapp] (3xN)

flag :

(optional) "n" -> matrix only; "p" -> matrix and rotation vector; "s" -> matrix, rotation vector and its time derivatives (defatul depends on number of outputs)

PREC:

precession matrix (3x3xN)

OM:

(optional) rotation vectors (3xN)

OMP:

(optional) first time derivative of OM (3xN)

Authors

CNES - DCT/SB

Bibliography

1 IERS Conventions (1996), Dennis D. McCarthy

2 Explanatory Supplement to the Astronomical Almanac, Seidelman (1992)

See also

CL_mod_precessionAngles, CL_rot_angles2matrix, CL_rot_angularVelocity

Examples

jj_tai = [19500:1:20500];
ss_tai = 43200*ones(jj_tai);
[K,KP,KPP]=CL_mod_precessionAngles(jj_tai,ss_tai,"s");
[PREC,OM,OMP] = CL_mod_precessionMatrix(K,KP,KPP,"s");