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Abstract
I/O
Examples
Particulars
Required Reading
Version
Index_Entries

Abstract


   CSPICE_PSV2PL returns a SPICE plane given a point and two
   spanning vectors.

I/O


   Given:

      point    [3,1] = size(point); double = class(point)

      span1    [3,1] = size(span1); double = class(span1)

      span2    [3,1] = size(span2); double = class(span2)

               are, respectively, a point and two spanning vectors
               that define a geometric plane in three-dimensional
               space. The plane is the set of vectors

                  point   +   s * span1   +   t * span2

               where 's' and 't' are real numbers.  The spanning
               vectors 'span1' and 'span2' must be linearly
               independent, but they need not be orthogonal or
               unitized.

   the call:

      [plane] = cspice_psv2pl(point, span1, span2 )

   returns:

      plane   a structure describing a SPICE plane defined
              by 'point', 'span1', and 'span2'.

              [1,1] = size(plane); struct = class(plane)

              The structure has the fields:

                 normal:     [3,1] = size(normal); double = class(normal)
                 constant:   [1,1] = size(constant); double = class(constant)

Examples


   Any numerical results shown for this example may differ between
   platforms as the results depend on the SPICE kernels used as input
   and the machine specific arithmetic implementation.

      %
      % Calculate the inclination of the Moon's orbit plane about
      % the Earth to the orbit plane of the Earth around the sun.
      %
      % We want a geometric analysis, so the calculation requires
      % no aberration correction.
      %
      epoch = 'Jan 1 2005';
      frame = 'ECLIPJ2000';
      corr  = 'NONE';

      %
      % Load the kernels we need to retrieve state data.
      %
      cspice_furnsh( 'standard.tm' )

      %
      % Convert the time string to  ephemeris time
      %
      et = cspice_str2et( epoch );

      %
      % Calculate the orbit plane of the Earth about
      % the solar system barycenter at epoch.
      %
      [state, ltime] = cspice_spkezr( 'EARTH', et, frame, corr, ...
                                      'Solar System Barycenter' );

      es_plane            = cspice_psv2pl( state(1:3), ...
                                           state(1:3), ...
                                           state(4:6) );
      [es_norm, es_const] = cspice_pl2nvc( es_plane );

      %
      % Calculate the orbit plane of the Moon with respect to
      % the Earth-Moon barycenter at epoch.
      %
      [state, ltime] = cspice_spkezr( 'MOON', et, frame, corr, ...
                                      'EARTH BARYCENTER' );

      em_plane            = cspice_psv2pl( state(1:3), ...
                                           state(1:3), ...
                                           state(4:6) );
      [em_norm, em_const] = cspice_pl2nvc( em_plane );

      %
      % Calculate the inclination equals (output in degrees).
      % Depending on the orientation of the plane normals, the
      % cspice_vsep result may exceed 90 degrees. If, so subtract
      % the value off 180 degrees.
      %
      loc_inc = cspice_vsep( es_norm, em_norm );

      if ( loc_inc > cspice_halfpi )
         loc_inc = cspice_pi - loc_inc;
      end

      fprintf( 'Moon-Earth orbit plane inclination (degrees): %f\n', ...
             loc_inc * cspice_dpr )

   Matlab outputs:

      Moon-Earth orbit plane inclination (degrees): 5.042496

Particulars


   Mice geometry routines that deal with planes use the `plane'
   data type to represent input and output planes.  This data type
   makes the subroutine interfaces simpler and more uniform.

   The Mice routines that produce SPICE planes from data that
   define a plane are:

      cspice_nvc2pl ( Normal vector and constant to plane )
      cspice_nvp2pl ( Normal vector and point to plane    )
      cspice_psv2pl ( Point and spanning vectors to plane )

   The Mice routines that convert SPICE planes to data that
   define a plane are:

      cspice_pl2nvc ( Plane to normal vector and constant )
      cspice_pl2nvp ( Plane to normal vector and point    )
      cspice_pl2psv ( Plane to point and spanning vectors )

   Any of these last three routines may be used to convert this
   routine's output, 'plane', to another representation of a
   geometric plane.

Required Reading


   For important details concerning this module's function, please refer to
   the CSPICE routine psv2pl_c.

   MICE.REQ
   PLANES.REQ

Version


   -Mice Version 1.0.0, 27-AUG-2012, EDW (JPL)

Index_Entries


   plane to point and spanning vectors


Wed Apr  5 18:00:34 2017