C+ C NAME: C Time2EclipticEquatorial C PURPOSE: C Converts ecliptic coordinates into equatorial coordinates or v.v. C CATEGORY: C Math: coordinate transformation C CALLING SEQUENCE: subroutine Time2EclipticEquatorial(id,tt,phi,lat) C CALLS: C Time2JEpoch, rotated C INPUTS: C id integer id=0: ecliptic ---> equatorial C id=1: equatorial ---> ecliptic C tt(2) integer 2-element standard time of current date C phi double precision ecliptic longitude/right ascension for equinox of current date C lat double precision ecliptic latitude/declination for equinox of current date C OUTPUTS: C phi double precision right ascension/ecliptic longitude C lat double precision declination/ecliptic latitude C CALLS: C Time2JEpoch, rotated C PROCEDURE: C See O. Montenbruck, Practical Ephemeris Calculations, p. 11 C If ID not equal 0 or 1 then ID = 0 is assumed. C MODIFICATION HISTORY: C JAN-2004, Paul Hick (UCSD/CASS; pphick@ucsd.edu) C- integer id integer tt(2) double precision phi double precision lat double precision eps double precision jepoch double precision beta call Time2JEpoch(2,1,tt,jepoch) ! Get Julian epoch (-2000) eps = 23.439291d0-0.00013004d0*jepoch ! Angle (ecliptic-equator) beta = eps ! To equatorial coord if (id .eq. 1) beta = -beta ! To ecliptic coord call rotated(90d0, beta, -90d0, phi, lat) return end