CL_fr_convertMat

Description

• Computes the frame transformation from frame1 to frame2, which is characterized by a frame transformation matrix M and an angular velocity vector omega.

  By convention:

  - multiplying M by coordinates relative to frame1 yields coordinates relative to frame2.

  - omega is the angular velocity vector of frame2 wrt frame1, with coordinates in frame1.

• The available frames are:

  

  In addition, 2 other frames (or names) are defined: ECI and ECF.

  See Reference frames for more details on the definition of reference frames.

• Notes:

  - The date 'cjd' is relative to the TREF time scale.

  - Which optional arguments need to be supplied depends on the frame transformation. See the frame transformation diagram for more details.

  - The frame names are case sensitive.

Parameters

cjd:

Modified Julian date from 1950.0 (TREF time scale) (1xN or 1x1)

frame1:

(string) Initial frame (1x1)

frame2:

(string) Final frame (1x1)

ut1_tref:

(optional) UT1-TREF [seconds]. Default is %CL_UT1_TREF (1xN or 1x1)

tt_tref:

(optional) TT-TREF [seconds]. Default is %CL_TT_TREF. (1xN or 1x1)

xp, yp:

(optional) Position of the pole in ITRS [rad](1xN or 1x1)

dX, dY:

(optional) Corrections to CIP coordinates [rad] (1xN or 1x1)

use_interp:

(optional, boolean) %t to use interpolation when computing CIP coordinates. Default is %t. (1x1)

M:

Frame transformation matrix from frame1 to frame2 (3x3xN)

omega:

Angular velocity vector of frame2 wrt frame1 with coordinates in frame1 [rad/s] (3xN)

Authors

• CNES - DCT/SB

Examples

// Frame transformation from Veis to EME2000 (All optional arguments to default) cjd_tref = 21010; [M,omega] = CL_fr_convertMat("Veis", "EME2000", cjd_tref); // Frame transformation from GCRS to TIRS cjd_tref = [21010 , 21011]; [M,omega] = CL_fr_convertMat("GCRS", "TIRS", cjd_tref, ut1_tref=-0.2);