KPL/IK JUNO Magnetometer Instrument Kernel =============================================================================== This Instrument Kernel (IK) file contains parameters for the JUNO Fluxgate Magnetometer (FGM) sensors and Field-Of-View (FOV) definitions for JUNO Advanced Stellar Compass (ASC) Camera Head Units (CHUs). Version and Date ------------------------------------------------------------------------------- Version 0.3 -- June 15, 2017 -- Boris Semenov, NAIF Filled in Instrument Description based on [5]. Version 0.2 -- March 29, 2012 -- Boris Semenov, NAIF Renamed CHUs in comments and their frames in the FOV definitions to be consistent with the new frame layout. Version 0.1 -- September 1, 2010 -- Boris Semenov, NAIF Updated based on review comments from Jack Connerney as follows: -- frame and instrument name change: ASC1 -> ASC_CHU1, ASC2 -> ASC_CHU2, ASC3 -> ASC_CHU3, ASC4 -> ASC_CHU4, Version 0.0 -- June 2, 2009 -- Boris Semenov, NAIF Initial Release. References ------------------------------------------------------------------------------- 1. Kernel Pool Required Reading 2. GETFOV, getfoc_c, cspice_getfov headers 3. JUNO FK file, latest version 4. JUNO FGM and ASC CDS Presentations 5. FGM PDS3 catalog file, INST_FGM.CAT, Rev 2016-05-06 Contact Information ------------------------------------------------------------------------------- Boris V. Semenov, NAIF/JPL, (818)-354-8136, Boris.Semenov@jpl.nasa.gov 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) 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 JUNO spacecraft ID number (-61) followed by a NAIF three digit ID code for one of the FGMs or ASC CHUs. This is the full list of names and IDs for the FGMs and ASC CHUs described by this IK file: JUNO_ASC_CHUD -61111 JUNO_ASC_CHUC -61112 JUNO_FGM_IB -61114 JUNO_ASC_CHUB -61121 JUNO_ASC_CHUA -61122 JUNO_FGM_OB -61124 The remainder of the keyword name is an underscore character followed by the unique name of the data item. For example, the ASC CHU1 boresight direction in the ASC CHU1 frame is specified by: INS-61111_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 --------------------------------------------------------- From [5]: The MAG Instrument Suite consists of two boom mounted observing platforms (MAG Optical Bench, or MOB) each supporting a vector Fluxgate Magnetometer (FGM) and two non-magnetic Advanced Stellar Compass (ASC) Camera Head Units (CHUs). The FGM uses two miniature ring-core fluxgate sensors to measure the magnetic field in three components of the vector field. The ASC determines the attitude of the MOB in inertial space and relative to the JUNO spacecraft's Stellar Reference Units (SRU). The FGM was built at the Goddard Space Flight Center (GSFC); the ASC was built at the Technical University of Denmark (DTU). The Juno MAG sensors are remotely mounted (at approximately 10 m and 12 m) along a dedicated MAG boom that extends along the spacecraft +x axis, attached to the outer end of one of the spacecraft's three solar array structures. Mounting Alignment -------------------------------------------------------- Refer to the latest version of the Juno Frames Definition Kernel (FK) [3] for the FGM reference frame definitions and mounting alignment information. ASC CHU FOVs ---------------------------------------------------------- The ASC CHU FOVs are defined as 14 by 20 degrees (from [4]) full-angle rectangular pyramids centered on the +Z axes of the corresponding ASC CHU frames. The smaller extent is in the XZ plane. \begindata INS-61111_FOV_FRAME = 'JUNO_ASC_CHUD' INS-61111_FOV_SHAPE = 'RECTANGLE' INS-61111_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-61111_FOV_CLASS_SPEC = 'ANGLES' INS-61111_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-61111_FOV_REF_ANGLE = ( 7.0 ) INS-61111_FOV_CROSS_ANGLE = ( 10.0 ) INS-61111_FOV_ANGLE_UNITS = 'DEGREES' INS-61112_FOV_FRAME = 'JUNO_ASC_CHUC' INS-61112_FOV_SHAPE = 'RECTANGLE' INS-61112_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-61112_FOV_CLASS_SPEC = 'ANGLES' INS-61112_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-61112_FOV_REF_ANGLE = ( 7.0 ) INS-61112_FOV_CROSS_ANGLE = ( 10.0 ) INS-61112_FOV_ANGLE_UNITS = 'DEGREES' INS-61121_FOV_FRAME = 'JUNO_ASC_CHUB' INS-61121_FOV_SHAPE = 'RECTANGLE' INS-61121_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-61121_FOV_CLASS_SPEC = 'ANGLES' INS-61121_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-61121_FOV_REF_ANGLE = ( 7.0 ) INS-61121_FOV_CROSS_ANGLE = ( 10.0 ) INS-61121_FOV_ANGLE_UNITS = 'DEGREES' INS-61122_FOV_FRAME = 'JUNO_ASC_CHUA' INS-61122_FOV_SHAPE = 'RECTANGLE' INS-61122_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-61122_FOV_CLASS_SPEC = 'ANGLES' INS-61122_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-61122_FOV_REF_ANGLE = ( 7.0 ) INS-61122_FOV_CROSS_ANGLE = ( 10.0 ) INS-61122_FOV_ANGLE_UNITS = 'DEGREES' \begintext FGM FOVs ---------------------------------------------------------- While a FOV concept is in general not applicable to a magnetometer, this IK file defines a 1 degree half-angle cone FOV centered on the +Z axis of the corresponding FGM frames for each of the two FGMs to facilitate FK/IK verification and testing. \begindata INS-61114_FOV_FRAME = 'JUNO_FGM_IB' INS-61114_FOV_SHAPE = 'CIRCLE' INS-61114_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-61114_FOV_CLASS_SPEC = 'ANGLES' INS-61114_FOV_REF_VECTOR = ( 0.0, 1.0, 0.0 ) INS-61114_FOV_REF_ANGLE = ( 1.0 ) INS-61114_FOV_ANGLE_UNITS = 'DEGREES' INS-61124_FOV_FRAME = 'JUNO_FGM_OB' INS-61124_FOV_SHAPE = 'CIRCLE' INS-61124_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-61124_FOV_CLASS_SPEC = 'ANGLES' INS-61124_FOV_REF_VECTOR = ( 0.0, 1.0, 0.0 ) INS-61124_FOV_REF_ANGLE = ( 1.0 ) INS-61124_FOV_ANGLE_UNITS = 'DEGREES' \begintext End of the IK file.