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Abstract
I/O
Examples
Particulars
Required Reading
Version
Index_Entries

Abstract


   CSPICE_SPKSSB returns the geometric state (position and 
   velocity) of a target body relative to the solar system 
   barycenter. 

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

I/O

   
   Given:
   
      targ    the string name or ID of the target body (the
              observed body)
              
      et      the double precision ephemeris time (ET) epoch
              for the observation of interest
              
      ref     the string name of the reference frame in
              which to output the state 6-vector
   
   the call:
   
      cspice_spkssb, targ, et, ref, starg
   
   returns:
   
      starg   a double precision 6-vector containing the position 
              and velocity of 'targ' relative to the Solar System 
              Barycenter at time 'et'.
   
   Note: The state vector returned by cspice_spkssb represents the
   geometric state of the target from the Solar System Barycenter.
   The routine applies no corrections to account for stellar 
   aberration or the finite speed of light.
   

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.

   
      ;;
      ;; Load a set of kernels: an SPK file, a PCK
      ;; file and a leapseconds file. Use a meta
      ;; kernel for convenience.
      ;;
      cspice_furnsh, 'standard.tm'
         
      ;;
      ;; Define parameters for a state lookup:
      ;;
      ;; Return the state vector of Mars (499)
      ;; and Earth (399) with respect to the Solar System
      ;; Barycenter in the J2000 frame at epoch
      ;; July 4, 2003 11:00 AM PST.
      ;;
      targ1  = 499
      epoch  = 'July 4, 2003 11:00 AM PST'
      frame  = 'J2000'
      targ2  = 399
         
      ;;
      ;; Convert the epoch to ephemeris time.
      ;;
      cspice_str2et, epoch, et
         
      ;;
      ;; Look-up the states for the defined parameters.
      ;;
      cspice_spkssb, targ1, et, frame, state1
      cspice_spkssb, targ2, et, frame, state2
   
      ;;
      ;; What measure of distance separates the two bodies
      ;; at epoch.
      ;;
      dist = cspice_vdist( state1[0:2], state2[0:2] )
   
      print, 'The absolute distance (KM)      : ', dist
      print, 'between Mars and Earth at epoch : ', epoch
   
   IDL outputs:
   
      The absolute distance (KM)      :        80854820.
      between Mars and Earth at epoch : July 4, 2003 11:00 AM PST
   
   Note, an cspice_spkgeo call equivalent to the two cspice_spkssb
   calls:
   
      cspice_spkgeo, targ1, et, frame, targ2, state, ltime
      dist = norm( state[0:2] )

Particulars


   None.

Required Reading


   ICY.REQ
   SPK.REQ
   FRAMES.REQ

Version


   -Icy Version 1.0.0, 16-JUN-2003, EDW (JPL)

Index_Entries

 
   state relative to solar system barycenter 
 



Wed Apr  5 17:58:03 2017