$LastChangedDate: 27-Juil-2011 $

# CL_fr_ter2J2000

Terrestrial frame to EME2000 (J2000) vector transformation

## Calling Sequence

       [pos_J2000,[vel_J2000,jacob]] = CL_fr_ter2J2000(cjd,pos_ter,[vel_ter,ut1_utc,xp,yp,dPsi,dEps,conv])

## Description

- Converts position and (optionally) velocity vectors from the terrestrial ("Earth fixed") reference frame to EME2000.

  The jacobian of the transformation is optionally computed.

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

## Parameters

cjd:

  modified julian day from 1950.0 (UTC) (1xN or 1x1)

pos_ter:

  position vector relative to terrestrial frame [m] (3xN or 3x1)

vel_ter:

  (optional) velocity vector relative to terrestrial frame [m/s] (3xN or 3x1)

ut1_utc :

  (optional) ut1-utc [seconds] (default is 0) (1xN or 1x1)

xp :

  (optional) x polar coordinate [radians] (default is 0) (1xN or 1x1)

yp :

  (optional) y polar coordinate [radians] (default is 0) (1xN or 1x1)

dPsi :

  (optional) Nutation corrections [radians] (default is 0) (1xN or 1x1)

dEps :

  (optional) Nutation corrections [radians] (default is 0) (1xN or 1x1)

conv :

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

pos_J2000:

  position vector relative to EME2000 [m] (3xN)

vel_J2000:

  (optional) velocity vector relative to EME2000 [m/s] (3xN)

jacob:

  (optional) jacobian of the transformation (6x6xN)

## Authors

- CNES - DCT/SB

## Bibliography

- 1) IERS Conventions (1996), Dennis D. McCarthy

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

## See also

- CL_fr_ter2J2000Mat

- CL_fr_J20002ter

## Examples

    // Conversion ter to J2000
    pos_ter = [ [1000.e3;7078.e3;700.e3] , [7000.e3;1078.e3;1700.e3] ];
    cjd = [21010 , 21011];
    pos_J2000 = CL_fr_ter2J2000(cjd,pos_ter);
    M=CL_fr_ter2J2000Mat(cjd);
    pos_J2000_2 = M*pos_ter;

    // Conversion ter to J2000
    pos_ter = [1000.e3;7078.e3;700.e3];
    vel_ter = [4.e3;4.2e3;3.e3];
    cjd = 20010;
    [pos_J2000,vel_J2000,jacob] = CL_fr_ter2J2000(cjd,pos_ter,vel_ter)