$LastChangedDate: 27-Juil-2011 $

# CL_fr_ter2J2000Mat

Terrestrial frame to EME2000 (J2000) transformation matrix

## Calling Sequence

       M = CL_fr_ter2J2000Mat(cjd[,ut1_utc[,xp,yp[,dPsi,dEps[,conv]]]])

## Description

- Computes the frame transformation matrix M from the terrestrial ("Earth fixed") reference frame to EME2000.

  By convention, multiplying M by coordinates relative to the terrestrial frame yields coordinates relative to EME2000.

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

## Parameters

cjd:

  modified julian days from 1950.0 (UTC) (1xN)

ut1_utc :

  (optional) ut1-utc [seconds] (default is 0) (1xN)

xp :

  (optional) x polar coordinate [radians] (default is 0) (1xN)

yp :

  (optional) y polar coordinate [radians] (default is 0) (1xN)

dPsi :

  (optional) Nutation corrections [radians] (default is 0) (1xN)

dEps :

  (optional) Nutation corrections [radians] (default is 0) (1xN)

conv :

  (optional) Convention IERS. Only iers 1996 (Lieske/Wahr) is implemented (default is "iers_1996")

M:

  terrestrial frame to EME2000 transformation matrix (3x3xN)

## 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_precessionMatrix

- CL_mod_nutationMatrix

- CL_mod_polarMotionMatrix

## Examples

    // Conversion J2000 to terrestrial
    pos_J2000=[[3500.e3;2500.e3;5800.e3] , [4500.e3;2100.e3;6800.e3]];
    cjd = [21010 , 21011];
    M=CL_fr_ter2J2000Mat(cjd);
    pos_ter = M' * (pos_J2000);
    // Conversion terrestrial to J2000
    pos_ter = [[3500.e3;2500.e3;5800.e3] , [4500.e3;2100.e3;6800.e3]];
    cjd = [21010 , 21011];
    M=CL_fr_ter2J2000Mat(cjd);
    pos_J2000 = M * (pos_ter);