Procedure

     SPKUDS ( SPK - unpack segment descriptor )

     SUBROUTINE SPKUDS ( DESCR,
    .                    BODY,  CENTER, FRAME,  TYPE,
    .                    FIRST, LAST,   BADDRS, EADDRS )

Abstract

     Unpack the contents of an SPK segment descriptor.

Required_Reading

     SPK

Keywords

     SPK

Declarations

     IMPLICIT NONE

     DOUBLE PRECISION      DESCR ( * )
     INTEGER               BODY
     INTEGER               CENTER
     INTEGER               FRAME
     INTEGER               TYPE
     DOUBLE PRECISION      FIRST
     DOUBLE PRECISION      LAST
     INTEGER               BADDRS
     INTEGER               EADDRS

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     DESCR      I   An SPK segment descriptor.
     BODY       O   The NAIF ID code for the body of the segment.
     CENTER     O   The center of motion for BODY.
     FRAME      O   The code for the frame of this segment.
     TYPE       O   The type of SPK segment.
     FIRST      O   The first epoch for which the segment is valid.
     LAST       O   The last  epoch for which the segment is valid.
     BADDRS     O   Beginning DAF address of the segment.
     EADDRS     O   Ending DAF address of the segment.

Detailed_Input

     DESCR    is an SPK segment descriptor.

Detailed_Output

     BODY     is the NAIF ID code for the body of the segment.

     CENTER   is the center of motion for BODY.

     FRAME    is the SPICE integer code for the frame to which states
              for the body are be referenced.

     TYPE     is the type of SPK segment.

     FIRST    is the first epoch for which the segment has
              ephemeris data.

     LAST     is the last epoch for which the segment has
              ephemeris data.

     BADDRS   is the starting address of the data associated
              with this descriptor.

     EADDRS   is the last address of the data associated with
              this descriptor.

Parameters

     None.

Exceptions

     Error free.

     1)  If the input descriptor DESCR is invalid, it's possible for
         the output times to contain bit patterns that don't represent
         normal double precision values. This error is not diagnosed.

Files

     None.

Particulars

     This routine extracts the contents of an SPK segment
     descriptor into the components needed for reading and
     evaluating the data stored in the segment. It serves
     as a macro for expanding the SPK segment descriptor.

Examples

     Suppose you wished to summarize a particular SPK segment
     and that you have the descriptor for that segment in hand.
     The following code fragment shows how you might use this
     routine to create a summary message concerning the segment.

        CALL SPKUDS ( DESCR, BODY,  CENTER, FRAME,
       .              TYPE,  FIRST, LAST,   BADDR, EADDR )

     Convert the start and stop times to ephemeris calendar strings

        CALL ETCAL ( FIRST, FSTCAL )
        CALL ETCAL ( LAST,  LSTCAL )

        WRITE (*,*)
        WRITE (*,*) 'Body     : ', BODY
        WRITE (*,*) 'Center   : ', CENTER
        WRITE (*,*) 'Frame ID : ', FRAME
        WRITE (*,*) 'Data Type: ', TYPE
        WRITE (*,*)
        WRITE (*,*) 'Segment Start : ', FSTCAL
        WRITE (*,*) 'Segment Stop  : ', LSTCAL

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman       (JPL)
     J. Diaz del Rio    (ODC Space)
     K.R. Gehringer     (JPL)
     W.L. Taber         (JPL)

Version

    SPICELIB Version 1.1.0, 02-OCT-2021 (JDR) (NJB)

        Changed output argument names "BEGIN" and "END" to "BADDRS" and
        "EADDRS" for consistency with other routines.

        Edited the header to comply with NAIF standard. Added entry
        #1 to $Exceptions section and declared the routine error free.

    SPICELIB Version 1.0.0, 04-JAN-1994 (WLT) (KRG)