CL_mod_IAUBodyAngles

Description

• This function computes the three rotation angles defining the IAU body-fixed rotating frame

  angles = [RA;DEC;W] with RA and DEC the right ascension and declination of the rotation axis of the body in the ICRS frame, and W the sidereal time of the body.

  The function also optionally computes the time derivatives of these angles: angles_der = [RAdot;DECdot;Wdot]

  Available bodies are: "Mercury","Venus","Earth","Mars","Jupiter","Saturn","Uranus", "Neptune", "Sun" and "Moon"

• Notes:

  - Rigorously, the date should be given in TDB time scale. In practice using a date in TT time scale leads to a negligible error (about 2 ms error on the date).

  - Body names are case sensitive

  - This implementation of the function is compliant with the 2009 IAU report. (See bibliography)

Parameters

cjd:

Modified (1950.0) julian day (Time scale: TREF) (1xN)

body:

(string) Name of the body. ("Mercury","Venus","Earth","Mars","Jupiter","Saturn","Uranus", "Neptune", "Sun" or "Moon") (1x1)

tt_tref:

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

Authors

• CNES - DCT/SB

Bibliography

• Report of the IAU/IAG working group on cartographic coordinates and rotational elements: 2009

See also

• CL_fr_bodyConvertMat

• CL_fr_bodyConvert

Examples

cjd = CL_dat_cal2cjd(2010,02,03,05,35,25); [angles,angles_der] = CL_mod_IAUBodyAngles(cjd, "Mars")