ExoMars-16 FREND Instrument Kernel
===========================================================================
     
   This ExoMars Trace Gas Orbiter instrument kernel (I-kernel) contains the 
   instrument geometric parameters for the Fine Resolution Epithermal 
   Neutron Detector (FREND).

     
Version and Date
--------------------------------------------------------

   Version 0.0 -- September 21, 2015 -- Anton Ledkov, IKI

References
--------------------------------------------------------
 
   1. http://l503.iki.rssi.ru/FREND-en.html

   2. "FREND Mechanical Interface Drawing."

   3. Kernel Pool Required Reading

   4. GETFOV, getfoc_c, cspice_getfov headers

   5. EXM_TGO FK file, latest version


Implementation Notes
--------------------------------------------------------
 
   This file is used by the SPICE system as follows: programs that make
   use of this kernel must "load" the kernel, normally during
   program initialization. The SPICE routine FURNSH loads a kernel file
   into the pool as shown below.

      CALL FURNSH ( 'frame_kernel_name; )    -- FORTRAN
      furnsh_c ( "frame_kernel_name" );      -- C
      cspice_furnsh, frame_kernel_name       -- IDL
      cspice_furnsh( 'frame_kernel_name' )   -- MATLAB

   Once the file has been loaded, the SPICE routine GETFOV (getfov_c in
   C, cspice_getfov in IDL and MATLAB) [4] can be used to retrieve FOV
   parameters for a given instrument or structure.

   This file was created and may be updated with a text editor or word
   processor.
 
 
Naming Conventions
--------------------------------------------------------
 
   All names referencing values in this IK file start with the
   characters "INS" followed by the NAIF TGO spacecraft ID number (-143)
   followed by a NAIF three digit ID code for the instrument or one of
   its detectors. This is the full list of names and IDs for the FREND
   detectors described by this IK file (these name/ID mapping are defined 
   at the bottom of this section):

      TGO_FREND_HE                    -143211
      TGO_FREND_SC                    -143212

   The remainder of the keyword name is an underscore character
   followed by the unique name of the data item. For example, the
   HE detector boresight direction in the TGO_FREND frame
   is specified by:

      INS-143210_BORESIGHT

   The upper bound on the length of the name of any data item is 32
   characters.
 
   If the same item is included in more than one file, or if the same
   item appears more than once within a single file, the latest value
   supersedes any earlier values.

Instrument Description
---------------------------------------------------------

   See [1].

Mounting Alignment
--------------------------------------------------------

   Refer to the latest version of the TGO Frames Definition Kernel
   (FK) [5] for the FREND reference frame definitions and mounting
   alignment information.


FOV Definition
--------------------------------------------------------
 
   The FREND_HE is defined below as 14-degree cones (per [1]) centered on 
   the -Y axis of the "EXM_TGO" reference frame.
 

      \begindata

      INS-143211_FOV_FRAME          = 'TGO_FREND_HE'
      INS-143211_FOV_SHAPE          = 'CIRCLE'
      INS-143211_BORESIGHT          = ( 0 -1 0 ) 
      INS-143211_FOV_CLASS_SPEC     = 'ANGLES'
      INS-143211_FOV_REF_VECTOR     = ( 0 1 0  )
      INS-143211_FOV_REF_ANGLE      = ( 0.209  )
      INS-143211_FOV_ANGLE_UNITS    = 'RADIANS'

      INS-143212_FOV_FRAME          = 'TGO_FREND_SC'
      INS-143212_FOV_SHAPE          = 'CIRCLE'
      INS-143212_BORESIGHT          = ( 0 -1 0 )
      INS-143212_FOV_CLASS_SPEC     = 'ANGLES'
      INS-143212_FOV_REF_VECTOR     = ( 0 1 0  )
      INS-143212_FOV_REF_ANGLE      = ( 0.244  )
      INS-143212_FOV_ANGLE_UNITS    = 'RADIANS'

      \begintext

End of IK File.