kepleq |
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ProcedureKEPLEQ ( Solve Kepler's Equation --- Equinoctial Form ) DOUBLE PRECISION FUNCTION KEPLEQ (ML,H,K) AbstractSolve the equinoctial version of Kepler's equation. Required_ReadingNone. KeywordsSPK DeclarationsIMPLICIT NONE DOUBLE PRECISION ML DOUBLE PRECISION H DOUBLE PRECISION K Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- ML I Mean longitude. H I h component of equinoctial elements. K I k component of equinoctial elements. The function returns the solution to the equinoctial version of Kepler's equation, given the mean longitude and the h and k components of the equinoctial elements. Detailed_InputML is the mean longitude of some body following two body motion. (Mean longitude = Mean anomaly + argument of periapse + longitude of ascending node.) H is the h component of the equinoctial element set ( h = ECC*SIN( arg of periapse + long ascending node) ) K is the k component of the equinoctial element set ( k = ECC*COS( arg of periapse + long ascending node) ) Detailed_OutputThe function returns the solution to the equinoctial version of Kepler's equation, given the mean longitude and the h and k components of the equinoctial elements. The solution is the value of F such that ML = F + H * COS(F) - K * SIN(F) Note that ECC = DSQRT ( K*K + H*H ) ParametersNone. Exceptions1) If the sum of the squares of H and K is not less than .9, the error SPICE(ECCOUTOFBOUNDS) is signaled. 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 signaled. FilesNone. ParticularsThis 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. ExamplesNone. RestrictionsNone. Literature_References[1] W. Owen and R. Vaughan, "Optical Navigation Program Mathematical Models," JPL Engineering Memorandum 314-513, August 9, 1991. Author_and_InstitutionJ. Diaz del Rio (ODC Space) W.L. Taber (JPL) VersionSPICELIB Version 1.0.1, 26-AUG-2021 (JDR) Edited the header to comply with NAIF standard. Updated $Procedure section for consistency with KPSOLV routine. SPICELIB Version 1.0.0, 11-DEC-1996 (WLT) |
Fri Dec 31 18:36:29 2021