               object designated by the input argument 'obsrvr' (see
               description below).

               'inst' must have a corresponding NAIF ID and a frame
               defined, as is normally done in a frame kernel. It
               must also have an associated reference frame and a FOV
               shape, boresight and boundary vertices (or reference
               vector and reference angles) defined, as is usually
               done in an instrument kernel.

               See the