KPL/IK ALICE Instrument kernel =========================================================================== This instrument kernel (I-kernel) contains Rosetta ALICE optics, detector, and field-of-view parameters. Version and Date --------------------------------------------------------------------------- Version 0.0 -- August 3, 2004 -- Boris Semenov, NAIF/JPL VERY PRELIMINARY VERSION. References --------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading'' 2. ``C-kernel Required Reading'' 3. ``ALICE EID, Part B'', ROS-EST-RS-3005/EID B, 2001-02-15 4. Rosetta Frames Definition Kernel (FK), latest version. 5. ``ALICE: Experiment User Manual'', 8225-EUM-01, 2002-12-XX Implementation Notes -------------------------------------------------------- Applications that need SPICE I-kernel data must ``load'' the I-kernel file, normally during program initialization. Loading the kernel using the SPICELIB routine FURNSH causes the data items and their associated values present in the kernel to become associated with a data structure called the ``kernel pool''. The application program may then obtain the value(s) for any IK data item using the SPICELIB routines GDPOOL, GIPOOL, GCPOOL. Routine GETFOV may be used if the file contains instrument field-of-view (FOV) specification. See [1] for details. This file was created with, and can be updated with a text editor or word processor. Conventions for Specifying Data -------------------------------------------------------- Data items are specified using ``keyword=value'' assignments [1]. All keywords referencing values in this I-kernel start with the characters `INS' followed by the NAIF Rosetta instrument ID code, constructed using the spacecraft ID number (-226) followed by the NAIF three digit ID number for ALICE (120). ALICE ID(s) is defined in [4]. The remainder of the keyword is an underscore character followed by the unique name of the data item. For example, the focal length of the ALICE optics is specified by INS-226120_FOCAL_LENGTH The upper bound on the length of all keywords is 32 characters. If a keyword is included in more then one file, or if the same keyword appears more than once within a single file, the last assignment supersedes any earlier assignments. Overview -------------------------------------------------------- [TBD] Mounting Alignment -------------------------------------------------------- Refer to the latest version of the Rosetta Frames Definition Kernel (FK) [4] for the ALICE reference frame definitions and mounting alignment information. Apparent FOV Layout -------------------------------------------------------- WARNING --- the description/diagram below have not been verified WARNING --- the description/diagram below do not show the slit configuration, with the three slit parts and the pinhole. This section provides a diagram illustrating the ALICE apparent detector layout in the corresponding reference frame. ^ | direction of | flight | ^ +Xalice (along track) | | | | 0.1 degrees | | | v Pixel 1 | Pixel 12 --- +---------|---------+ | 1 line | x-------------> +Yalice (cross track) --- +-------------------+ ^ 12 pixels/line | | 6 degrees | |<----------------->| | | Boresight (+Z axis) is into the page Although there are 24 physical pixels in cross-track, spatial direction, they are used in pairs. So the total number of "spatial" resolution pixels in the line could be considered to be 12. As the light entering the instrument passes through a narrow slit parallel to the +Y axis (cross-track direction), the apparent size FOV in along-track direction is equivalent to just one line (as shown on the diagram.) The physical 1024 lines that the detector has in the along-track direction are used to achieve desired spectral resolution. Optical Parameters -------------------------------------------------------- The following ALICE nominal first order optical parameters are included in the data section below, from [3]: ----------------------------------------------------------------- parameter value note ----------------------------------------------------------------- Focal Length, mm 120.0 f/ratio f/3 IFOV, rad/pixel Cross-track 0.008727 Along-track 0.001745 Field of view (deg) Cross-track 6.0 Along-track 0.1 ----------------------------------------------------------------- FOV and IFOV parameters above are for the spatial direction. The keywords below provide nominal values from the table above. Angular size values in the keywords are given radians, with the cross-track size being the first value and the along-track size being the second value in each pair. \begindata INS-226120_FOCAL_LENGTH = ( 120.0 ) INS-226120_F/RATIO = ( 3.0 ) INS-226120_FOV_ANGULAR_SIZE = ( 0.104720, 0.001745 ) INS-226120_IFOV = ( 0.008727, 0.001745 ) \begintext Detector Parameters -------------------------------------------------------- The nominal ALICE detector parameters from [6] are: ----------------------------------------------------------------- parameter value note ----------------------------------------------------------------- Detector Array Size ---- Physical Cross-track 36 center 24 are used is pairs Along-track 1024 spectral dimension Detector Array Size ---- Spatial Cross-track 12 each is a physical pixels Along-track 1 Detector Array Center -- Spatial Cross-track 5.5 Along-track 0.5 Pixel Size, microns ---- Spatial Cross-track 1047.0 computed from IFOV and FL Along-track 209.4 computed from IFOV and FL ----------------------------------------------------------------- The values are given in microns for PIXEL_SIZE keywords and in counts for PIXEL_SAMPLES, PIXEL_LINES, and CENTER keywords. \begindata INS-226120_PIXEL_SIZE = ( 1047.0, 209.4 ) INS-226120_PIXEL_SAMPLES = ( 12 ) INS-226120_PIXEL_LINES = ( 1 ) INS-226120_CCD_CENTER = ( 5.5, 0.5 ) \begintext FOV Definitions --------------------------------------------------------------------------- This section contains definitions for the ALICE FOV. This definition is provided in a format consistent required by the SPICE (CSPICE) function GETFOV (getfov_c). The set of assignments in the data section below defines the ALICE FOV with respect to the ROS_ALICE frame to be a rectangle with the corners defined by the first and last pixels of the spatial, cross-track line and the boresight along the +Z axis of the ROS_ALICE frame. This FOV definition uses angular extent style specification with the cross and along track angular sizes taken from the ``Optics Parameters'' section above. \begindata INS-226120_FOV_FRAME = 'ROS_ALICE' INS-226120_FOV_SHAPE = 'RECTANGLE' INS-226120_BORESIGHT = ( 0.000000 0.000000 120.000000 ) INS-226120_FOV_CLASS_SPEC = 'ANGLES' INS-226120_FOV_REF_VECTOR = ( 1.000000 0.000000 0.000000 ) INS-226120_FOV_REF_ANGLE = ( 0.05 ) INS-226120_FOV_CROSS_ANGLE = ( 3.00 ) INS-226120_FOV_ANGLE_UNITS = 'DEGREES' \begintext Optical Distortion -------------------------------------------------------- [TBD] Platform ID --------------------------------------------------------------------------- This number is the NAIF instrument ID of the platform on which the instrument mounted. For ALICE it is the spacecraft. \begindata INS-226120_PLATFORM_ID = ( -226000 ) \begintext