Procedure

     SPKE01 ( S/P Kernel, evaluate, type 1 )

     SUBROUTINE SPKE01 ( ET, RECORD, STATE )

Abstract

     Evaluate a single SPK data record from a segment of type 1
     (Difference Lines).

Required_Reading

     SPK

Keywords

     EPHEMERIS

Declarations

     IMPLICIT NONE

     DOUBLE PRECISION      ET
     DOUBLE PRECISION      RECORD   ( * )
     DOUBLE PRECISION      STATE    ( 6 )

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     ET         I   Target epoch.
     RECORD     I   Data record.
     STATE      O   State (position and velocity).

Detailed_Input

     ET       is a target epoch, at which a state vector is to
              be computed.

     RECORD   is a data record which, when evaluated at epoch ET,
              will give the state (position and velocity) of some
              body, relative to some center, in some inertial
              reference frame.

Detailed_Output

     STATE    is the state. Units are km and km/sec.

Parameters

     None.

Exceptions

     None.

Files

     None.

Particulars

     The exact format and structure of type 1 (difference lines)
     segments are described in the SPK Required Reading file.

     Difference lines (DL's) are generated by JPL navigation
     system programs P and PV. Each data record is equivalent
     to the (slightly rearranged) 'P' portion of a NAVIO PV file
     data record.

     SPKE01 is a specialized version of Fred Krogh's subroutine DAINT.
     Only the calling sequence has been changed.

     Because the original version was undocumented, only Fred
     knows how this really works.

Examples

     None.

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     F.T. Krogh         (JPL)
     H.A. Neilan        (JPL)
     W.L. Taber         (JPL)
     I.M. Underwood     (JPL)

Version

    SPICELIB Version 1.2.0, 14-APR-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard. Moved SPK
        required reading from $Literature_References to
        $Required_Reading section.

    SPICELIB Version 1.1.0, 14-FEB-1997 (WLT)

        The goto's were removed and loop and if structures
        revealed. We still don't know exactly what's going
        on, but at least the bones of this routine have been
        cleaned off and are ready for assembly. (WLT)

    SPICELIB Version 1.0.4, 30-OCT-1996 (WLT)

        Removed redundant SAVE statements from the declaration
        section. Thanks to Steve Schlaifer for finding this
        error.

    SPICELIB Version 1.0.3, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 1.0.2, 23-AUG-1991 (HAN)

        SPK01 was removed from the $Required_Reading section of the
        header. The information in the SPK01 Required Reading file
        is now part of the SPK Required Reading file.

    SPICELIB Version 1.0.1, 22-MAR-1990 (HAN)

        Literature references added to the header.

    SPICELIB Version 1.0.0, 31-JAN-1990 (IMU) (FTK)