Index Page spkw10_c

A B C D E F G H I J K L M N O P Q R S T U V W X

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

#### Procedure

       void spkw10_c ( SpiceInt           handle,
                       SpiceInt           body,
                       SpiceInt           center,
                       ConstSpiceChar   * frame,
                       SpiceDouble        first,
                       SpiceDouble        last,
                       ConstSpiceChar   * segid,
                       ConstSpiceDouble   consts [8],
                       SpiceInt           n,
                       ConstSpiceDouble   elems  [],
                       ConstSpiceDouble   epochs []  )

#### Abstract

       Write an SPK type 10 segment to the DAF open and attached to
       the input handle.

#### Required_Reading

       None.

#### Keywords

       SPK

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       handle     I   The handle of a DAF file open for writing.
       body       I   The NAIF ID code for the body of the segment.
       center     I   The center of motion for body.
       frame      I   The reference frame for this segment.
       first      I   The first epoch for which the segment is valid.
       last       I   The last  epoch for which the segment is valid.
       segid      I   The string to use for segment identifier.
       consts     I   The array of geophysical constants for the segment
       n          I   The number of element/epoch pairs to be stored
       elems      I   The collection of "two-line" element sets.
       epochs     I   The epochs associated with the element sets.

#### Detailed_Input

       handle      is the file handle of an SPK file that has been
                   opened for writing by spcopn, dafopn, or dafopw.

       body        is the NAIF ID for the body whose states are
                   to be recorded in an SPK file.

       center      is the NAIF ID for the center of motion associated
                   with body.

       frame       is the reference frame that states are referenced to,
                   for example "J2000".

       first       are the bounds on the ephemeris times, expressed as
       last        seconds past J2000, for which the states can be used
                   to interpolate a state for body.

       segid       is the segment identifier. An SPK segment identifier
                   may contain up to 40 characters.

       consts      are the geophysical constants needed for evaluation
                   of the two line elements sets.  The order of these
                   constants must be:

                   consts[0] = J2 gravitational harmonic for earth
                   consts[1] = J3 gravitational harmonic for earth
                   consts[2] = J4 gravitational harmonic for earth
                   consts[3] = Square root of the GM for earth where GM
                               is expressed in earth radii cubed per
                               minutes squared
                   consts[4] = Equatorial radius of the earth in km
                   consts[5] = Low altitude bound for atmospheric
                               model in km
                   consts[6] = High altitude bound for atmospheric
                               model in km
                   consts[7] = Distance units/earth radius (normally 1)

       n           is the number of "two-line" element sets  and epochs
                   to be stored in the segment.

       elems       contains a time-ordered array of two-line elements
                   as supplied in NORAD two-line element files.  The
                   i'th set of elements (where i ranges from 1 to n)
                   should be stored as shown here:

                      base = (i-1)*10

                      elems ( base + 0 ) = NDT20
                      elems ( base + 1 ) = NDD60
                      elems ( base + 2 ) = BSTAR
                      elems ( base + 3 ) = INCL
                      elems ( base + 4 ) = NODE0
                      elems ( base + 5 ) = ECC
                      elems ( base + 6 ) = OMEGA
                      elems ( base + 7 ) = MO
                      elems ( base + 8 ) = NO
                      elems ( base + 9 ) = EPOCH

                   The meaning of these variables is defined by the
                   format of the two-line element files available from
                   NORAD.

       epochs      contains the epochs (ephemeris seconds past J2000)
                   corresponding to the elements in elems.  The I'th
                   epoch must equal the epoch of the I'th element set
                   Epochs must form a strictly increasing sequence.

#### Detailed_Output

       None.       The data input is stored in an SPK segment in the
                   DAF connected to the input handle.

#### Parameters

       None.

#### Exceptions

       1) Errors in the structure or content of the inputs must be
          diagnosed by routines called by this one.

       2) File access errors are diagnosed by routines in the
          call tree of this routine.

       3) If either the input frame or segment ID string pointer is null,
          the error SPICE(NULLPOINTER) is signaled.

       4) If either the input frame or segment ID string is empty,
          the error SPICE(EMPTYSTRING) is signaled.

#### Files

       None.

#### Particulars

       This routine writes a type 10 SPK segment to the DAF open
       for writing that is attached to handle.  A routine, GETELM, that
       reads two-line element data from files distributed by
       NORAD is available from NAIF.

#### Examples

       Suppose that you have collected the two-line element data
       and geophysical constants as prescribed above.  The following
       code fragment demonstrates how you could go about creating
       a type 10 SPK segment.

          #include "SpiceUsr.h"
              .
              .
              .
          /.
          Open a new SPK file using DAF and get a file handle.
          ./
          body   = <integer code for the body>;
          center = <integer code for central body for the trajectory>;
          frame  = "J2000";
          segid  = <string that gives the bodies name>;

          fname  = "SAMPLE.SPK";
          ifname = "SAMPLE SPK FILE FOR PRIVATE USE";
          ncomch =  0;

          void spkopn_c ( fname, ifname, ncomch, &handle );

          /.
          Add the type 10 data.
          ./
          spkw10_c ( handle, body,   center, frame,  first, last,
                     segid,  consts, n,      elems,  epochs      );

          /.
          Close the SPK properly.
          ./
          spkcls_c ( handle );

#### Restrictions

       None.

#### Literature_References

       None.

#### Author_and_Institution

       N.J. Bachman    (JPL)
       W.L. Taber      (JPL)

#### Version

       -CSPICE Version 1.0.1, 30-OCT-2006 (BVS)

          Deleted "inertial" from the FRAME description in the Brief_I/O
          section of the header.

       -CSPICE Version 1.0.0, 29-JUN-1999 (NJB) (WLT)

#### Index_Entries

       write a type_10 spk segment

#### Link to routine spkw10_c source file spkw10_c.c

    Wed Apr  5 17:54:44 2017