Name

CL_mod_sidTime — Greenwich mean sideral time (IERS 1996)

Calling Sequence

   [gmst,[gmstp]]=CL_mod_sidTime(cjd_ut1)
   
   

Description

  • Calculate Greenwich mean sideral time gmst (IERS 1996).

    It also optionally computes the first derivative of the sideral time : gmstp. (this value is not a constant)

  • Last update : 27/03/2007

Parameters

cjd_ut1:

CNES julian date in UT1 time scale(1xN)

gmst :

greenwich mean sideral time [rad]

gmstp :

greenwich mean sideral time first derivative [rad/s]

Authors

CNES - DCT/SB

Bibliography

IERS Conventions (1996), Dennis D. McCarthy

See also

CL_mod_sidTimeG50

Examples

cjd_utc = CL_dat_cal2cjd(2008,10,25,15,30,25)  // 25 oct 2008 at 15h30min25s
sec_ut1_minus_utc = 0.2;
cjd_ut1 = cjd_utc + sec_ut1_minus_utc/86400.;  // ut1 time
gmst = CL_mod_sidTime(cjd_ut1);
[gmst,gmstp] = CL_mod_sidTime(cjd_ut1);

// With first time derivative :
[gmst,gmstp] = CL_mod_sidTime(21915.121212)