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Procedure
Abstract
Required_Reading
Keywords
Declarations
Brief_I/O
Detailed_Input
Detailed_Output
Parameters
Exceptions
Files
Particulars
Examples
Restrictions
Literature_References
Author_and_Institution
Version

Procedure

      KEPLEQ ( Kepler's Equation - Equinoctial Version )
 
      DOUBLE PRECISION FUNCTION KEPLEQ (ML,H,K)
 
 

Abstract

    This function solves the equinoctial version of Kepler's
    equation.

Required_Reading

     None.

Keywords

     SPK

Declarations

 
      IMPLICIT NONE
      DOUBLE PRECISION  ML
      DOUBLE PRECISION  H
      DOUBLE PRECISION  K
 

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     ML         I   Mean longitude
     H          I   h component of equinoctial elements
     K          I   k component of equinoctial elements

Detailed_Input

     ML         mean longitude of some body following two body
                motion.  (Mean longitude = Mean anomaly + argument
                of periapse + longitude of ascending node.)

     H          The h component of the equinoctial element set
                ( h = ECC*SIN( arg of periapse + long ascending node) )

     K          The k component of the equinoctial element set
                ( k = ECC*COS( arg of periapse + long ascending node) )

     Note that ECC = DSQRT ( K*K + H*H )

Detailed_Output

     The function returns the value of F such that
     ML = F + h*COS(F) - k*SIN(F)

Parameters

     None.

Exceptions

     1) If the sum of the squares of F and K is not less than .9
        the error 'SPICE(ECCOUTOFBOUNDS)' will be signalled.

     2) If the iteration for a solution to the equinoctial Kepler's
        equation does not converge in 10 or fewer steps, the error
        'SPICE(NOCONVERGENCE)' is signalled.

Files

     None.

Particulars

     This routine solves the equinoctial element version of
     Kepler's equation.

        ML = F + h*COS(F) - k*SIN(F)

     Here F is an offset from the eccentric anomaly E.

        F = E - argument of periapse - longitude of ascending node.

     where E is eccentric anomaly.

Examples

     None.

Restrictions

     None.

Literature_References

     "Optical Navigation Program Mathematical Models" JPL
     Engineering Memorandum 314-513.  By William M. Owen
     August 9, 1991.

Author_and_Institution

     W.L. Taber      (JPL)

Version

    SPICELIB Version 1.0.0, 11-DEC-1996 (WLT)
Wed Apr  5 17:46:49 2017