             [1,c4] = size(obsrvr); char = class(obsrvr)

                  or

               [1,1] = size(obsrvr); cell = class(obsrvr)

      dref     the name of the reference frame relative to which the
               input direction vector is expressed. This may be any
               frame supported by the SPICE system, including built-in
               frames (documented in the Frames Required Reading) and
               frames defined by a loaded frame kernel (FK).

               [1,c5] = size(dref