KPL/IK GIM Instrument Kernel =========================================================================== This instrument kernel (I-kernel) contains the mounting alignment, FOV geometry information and internal parameter values for the Genesis Ion Monitor (GIM) Instrument. Version and Date -------------------------------------------------------- Version 1.0 -- July 6, 2000 -- Boris Semenov, NAIF/JPL Initial Release. References -------------------------------------------------------- 1. ``Kernel Pool Required Reading'' 2. Genesis Frame Definitions Kernel, latest version. 3. Genesis Misson Plan (Doc.# GN-61000-202), October 1, 1999 4. LANL IOM "Alignment of Genesis Monitors", June 20, 2000 5. GIM Design/Measured CEM Geometry Chart, by LANL, June 2000 Implementation Notes -------------------------------------------------------- This file is used by the SPICE system as follows: programs that make use of this I-kernel must `load' the kernel, normally during program initialization. Loading the kernel associates data items with their names in a data structure called the `kernel pool'. The SPICELIB routine LDPOOL loads a kernel file into the pool as shown below. CALL LDPOOL ( I_kernel_name ) In order for a program or subroutine to extract data from the pool, the SPICELIB routines GDPOOL and GIPOOL are used. See [4] for more details. This file was created and can be updated with a text editor or word processor. Naming Conventions -------------------------------------------------------- All names referencing values in this I-kernel start with the characters `INS' followed by the NAIF GNS spacecraft ID number (-47) followed by the NAIF three digit GIM instrument reference number (200) or GIM CEM reference number (201...208). The remainder of the name is an underscore character followed by the unique name of the data item. For example, the GIM CEM #1 FOV shape is specified by INS-47201_FOV_SHAPE The upper bound on the length of the name of any data item is 32 characters. If the same item is included in more then one file, or if the same item appears more than once within a single file, the latest value supersedes any earlier values. GIM description -------------------------------------------------------- From [?]: [to be added] GIM Instrument Performance Parameters -------------------------------------------------------- Nominal GIM Instrument Performance Parameters as provided in [5]: -------------------------- -------------- ---------------- parameter value units -------------------------- -------------- ---------------- Analyzer Bending Angle 120 deg Central Radius 60 mm Plate Gap 1.8 mm Analyzer Constant 33.3 (aver, radius/gap ) Analyzer K (Energy/Volts) 16.2 (*) Polar Angle Resolution 3.0 deg - FWHM (*) Polar Angle Range +/- 12 deg (*) Azimuthal Angle Resolution 3.8 deg - FWHM (*) Azimuthal Angle Range 360 deg (provided by s/c rotation) Energy range 1 .. 15,000 eV Energy resolution 5.8 % - FWHM (*) Number of Polar pixels 8 -------------------------- -------------- ---------------- (*) these parameters are incorporated into the CEM frame and FOV definitions. These values are provided in the keywords below in the same units as in the table above: \begindata INS-47200_ANALYZER_BENDING_ANGLE = 120 INS-47200_CENTRAL_RADIUS = 60 INS-47200_PLATE_GAP = 1.8 INS-47200_ANALYZER_CONSTANT = 33.3 INS-47200_ANALYZER_K = 16.2 INS-47200_ENERGY_RANGE = ( 1, 15000 ) INS-47200_ENERGY_RESOLUTION = 5.8 \begintext GIM Mounting alignment -------------------------------------------------------- GIM mounting alignment is incorporated into the GIM frame definition provided in the Genesis Frames definition kernel [2]. GIM FOV Definition -------------------------------------------------------- The orientation of the GIM FOV with respect to the GIM Base Frame (see [2]) is shown on the diagram below: GIM +Y side view: ----------------- +Zgim ^ / cem1 .... .... cem8 ^ (+polar) . / . (-polar) +X Spacecraft | . . (spin axis) | . / . | <-_ . .<-- GIM FOV, "Polar range" | +Xgim --_ . / . nominally 24 degrees --_ . .___ | o | | +Ygim | | | | | |_________| GIM Mounting / \ Plate ________/_____________\ | | Spacecraft YZ plane _____|_______________________|_ / / / / / / / / / / / / / / / | / / / / Spacecraft Deck / / / /| GIM +X side view (approx.): --------------------------- +Zgim (approx.) ^ | (+azimuth) .|. (-azimuth) ^ .|. +X Spacecraft | .|. (spin axis) | .|.<-- GIM FOV, "Azimuthal range" | .|. nominally 3.8 degrees | .|. _________.|. | o --------------> | +Xgim | +Ygim | (approx.)| | | _|____________|_ GIM Mounting | | Plate _|________________|_ | | Spacecraft YZ plane _____|____________________|______ / / / / / / / / / / / / / / / / / / / / Spacecraft Deck / / / / / Combined GIM FOV is circumscribed around FOVs of individual CEMs. It has "rectangular" shape and is defined with respect to the GNS_GIM frame (see [2]). Nominal angular size of the FOV is 24 degrees (in XZ plane of GNS_GIM_BASE frame) by 3.8 degrees (in YZ plane of GNS_GIM_BASE frame) (see [5].) The FOV boresight is along +Z axis of the GNS_GIM frame. The set of keywords defining GIM FOV is consistent with the SPICELIB/cspice's GETFOV/getfoc_c interface. \begindata INS-47200_FOV_FRAME = 'GNS_GIM_BASE' INS-47200_FOV_SHAPE = 'RECTANGLE' INS-47200_BORESIGHT = ( 0.0 0.0 1.0 ) INS-47200_FOV_BOUNDARY_CORNERS = ( .212556561670 .033173416604 1.0 -.212556561670 .033173416604 1.0 -.212556561670 -.033173416604 1.0 .212556561670 -.033173416604 1.0 ) \begintext GIM CEM FOV Definitions -------------------------------------------------------- FOV of a particular GIM CEM is defined with respect to that CEM's frame (see [2]) with the boresight along +Z axis of the frame. All CEM FOVs nominally have "rectangular" shape and angular size of 3 degrees (in CEM's frame XZ plane) by 3.8 degrees (in CEM's frame YZ plane) (see [5].) The sets of keywords defining CEM FOVs are consistent with the SPICELIB/cspice's GETFOV/getfoc_c interface. \begindata INS-47201_FOV_FRAME = 'GNS_GIM_CEM1' INS-47201_FOV_SHAPE = 'RECTANGLE' INS-47201_BORESIGHT = ( 0.0 0.0 1.0 ) INS-47201_FOV_BOUNDARY_CORNERS = ( .026185921569 .033173416604 1.0 -.026185921569 .033173416604 1.0 -.026185921569 -.033173416604 1.0 .026185921569 -.033173416604 1.0 ) INS-47202_FOV_FRAME = 'GNS_GIM_CEM2' INS-47202_FOV_SHAPE = 'RECTANGLE' INS-47202_BORESIGHT = ( 0.0 0.0 1.0 ) INS-47202_FOV_BOUNDARY_CORNERS = ( .026185921569 .033173416604 1.0 -.026185921569 .033173416604 1.0 -.026185921569 -.033173416604 1.0 .026185921569 -.033173416604 1.0 ) INS-47203_FOV_FRAME = 'GNS_GIM_CEM3' INS-47203_FOV_SHAPE = 'RECTANGLE' INS-47203_BORESIGHT = ( 0.0 0.0 1.0 ) INS-47203_FOV_BOUNDARY_CORNERS = ( .026185921569 .033173416604 1.0 -.026185921569 .033173416604 1.0 -.026185921569 -.033173416604 1.0 .026185921569 -.033173416604 1.0 ) INS-47204_FOV_FRAME = 'GNS_GIM_CEM4' INS-47204_FOV_SHAPE = 'RECTANGLE' INS-47204_BORESIGHT = ( 0.0 0.0 1.0 ) INS-47204_FOV_BOUNDARY_CORNERS = ( .026185921569 .033173416604 1.0 -.026185921569 .033173416604 1.0 -.026185921569 -.033173416604 1.0 .026185921569 -.033173416604 1.0 ) INS-47205_FOV_FRAME = 'GNS_GIM_CEM5' INS-47205_FOV_SHAPE = 'RECTANGLE' INS-47205_BORESIGHT = ( 0.0 0.0 1.0 ) INS-47205_FOV_BOUNDARY_CORNERS = ( .026185921569 .033173416604 1.0 -.026185921569 .033173416604 1.0 -.026185921569 -.033173416604 1.0 .026185921569 -.033173416604 1.0 ) INS-47206_FOV_FRAME = 'GNS_GIM_CEM6' INS-47206_FOV_SHAPE = 'RECTANGLE' INS-47206_BORESIGHT = ( 0.0 0.0 1.0 ) INS-47206_FOV_BOUNDARY_CORNERS = ( .026185921569 .033173416604 1.0 -.026185921569 .033173416604 1.0 -.026185921569 -.033173416604 1.0 .026185921569 -.033173416604 1.0 ) INS-47207_FOV_FRAME = 'GNS_GIM_CEM7' INS-47207_FOV_SHAPE = 'RECTANGLE' INS-47207_BORESIGHT = ( 0.0 0.0 1.0 ) INS-47207_FOV_BOUNDARY_CORNERS = ( .026185921569 .033173416604 1.0 -.026185921569 .033173416604 1.0 -.026185921569 -.033173416604 1.0 .026185921569 -.033173416604 1.0 ) INS-47208_FOV_FRAME = 'GNS_GIM_CEM8' INS-47208_FOV_SHAPE = 'RECTANGLE' INS-47208_BORESIGHT = ( 0.0 0.0 1.0 ) INS-47208_FOV_BOUNDARY_CORNERS = ( .026185921569 .033173416604 1.0 -.026185921569 .033173416604 1.0 -.026185921569 -.033173416604 1.0 .026185921569 -.033173416604 1.0 ) \begintext Platform ID -------------------------------------------------------- The GIM in mounted on the GNS spacecraft deck. Therefore the value in the keyword below is -47000. \begindata INS-47200_PLATFORM_ID = ( -47000 ) \begintext