setsun.f

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      SUBROUTINE setsun(T,ES)
C  VERSION 1/31/87
C  PURPOSE
C    SETS UP SOME SOLAR ORBITAL ELEMENTS OF THE BUILT-IN LUNI-SOLAR
C    EPHEMERIDES
C  INPUT ARGUMENTS
C    T      = CURRENT JULIAN TIME (SEC)
C  OUTPUT ARGUMENTS
C    ES     = MEAN ORBITAL ELEMENTS OF THE SUN IN EARTH MEAN EQUATOR
C             AND EQUINOX OF DATE
C      (1)  = A, SEMI-MAJOR AXIS (KM)
C      (2)  = E, ECCENTRICITY
C      (3)  = I, INCLINATION (RAD)
C      (4)  = CAPW, LONGITUDE OF ASCENDING NODE, =0 BY DEFINITION
C      (5)  = W, ARGUMENT OF PERIAPSIS (RAD)
C  CALL SUBROUTINES
C    NONE
C  REFERENCES
C    JPL EM 312/86-153, 20 APRIL 1987
C    EXPLANATORY SUPPLEMENT TO THE ASTRONOMICAL EPHEMERIS AND THE
C      AMERICAN EPHEMERIS AND NAUTICAL ALMANAC
C  ANALYSIS
C    JOHNNY H. KWOK - JPL
C  PROGRAMMER
C    JOHNNY H. KWOK - JPL
C  MODIFICATIONS
C    NONE
C  COMMENTS
C    NONE
C
      IMPLICIT DOUBLE PRECISION (a-h,o-z)
      dimension es(7)
      DATA rjd/2.41502d6/
      DATA dts/8.64d4/
      dt=t/dts-rjd
      dt1=dt*1.d-4
      dt2=dt1*dt1
      dt3=dt1*dt2
      es(1)=1.496d8
      es(2)=1.675104d-2-1.1444d-5*dt1-9.4d-9*dt2
      es(3)=.4093197474d0-6.217910d-5*dt1-2.1468d-9*dt2+1.7977d-10*dt3
      es(4)=0.d0
      es(5)=4.908229653d0+8.2149855d-7*dt+5.9167d-7*dt2+1.22d-9*dt3
      RETURN
      END