KPL/IK Psyche Imager Instrument Kernel ============================================================================== This instrument kernel (I-kernel) contains Imager A (IMGA) and Imager B (IMGB) optics, detector, and field-of-view parameters. Version and Date ------------------------------------------------------------------------------ Version 0.4 -- April 26, 2021 -- Matt Barnes, NAIF/JPL Changed IDs to start with -255 instead of -69 to reflect PSYCH S/C ID change to -255, see [3] for details. Version 0.3 -- May 20, 2018 -- Boris Semenov, Masha Liukis, NAIF/JPL * Added new reference document. * Updated f/ratio settings (see [5]). * Updated FOV diagram and swapped angles in the FOV definition to match the updated frames. Version 0.2 -- January 31, 2018 -- Masha Liukis, NAIF/JPL Replaced references to camera with references to imager. Replaced FC (framing camera) with IMG (imager) for instruments and frames names: PSYC_FC1 with PSYC_IMGA PSYC_FC2 with PSYC_IMGB Version 0.1 -- January 29, 2018 -- Boris Semenov, NAIF/JPL Preliminary version based on the mission proposal information; to be reviewed by the instrument team and updated based on their feedback. Updated some descriptions, diagrams, indentation, and paragraph wrapping. Version 0.0 -- May 5, 2017 -- Masha Liukis, NAIF/JPL Preliminary version. References ------------------------------------------------------------------------------ 1. ``Kernel Pool Required Reading'' 2. ``C-kernel Required Reading'' 3. Psyche Frames Definition Kernel (FK), latest version. 4. 02_Psyche_CSR_Redacted_Science.pdf. 5. Psyche Multispectral Imager Specifications. Contact Information ------------------------------------------------------------------------------ Matt Barnes, NAIF/JPL, (818) 354-5942, matthew.j.barnes@jpl.nasa.gov 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 (see [1]). All keywords referencing values in this I-kernel start with the characters `INS' followed by the NAIF Psyche instrument ID code, constructed using the spacecraft ID number (-255) followed by the NAIF three digit ID number. This number identifies the generic IMGA or IMGB. The ID numbers are defined in [3] as follows: Instrument name ID -------------------- ------- PSYC_IMGA -255110 PSYC_IMGB -255130 The remainder of the keyword is an underscore character followed by the unique name of the data item. For example, the f/ratio of IMGA is specified by INS-255110_F/RATIO The upper bound on the length of all keywords is 32 characters. If a keyword is included in more than one file, or if the same keyword appears more than once within a single file, the last assignment supersedes any earlier assignments. Overview ------------------------------------------------------------------------------ The multispectral imager consists of a pair of identical cameras designed to acquire geologic, compositional, and topographic data. The purpose of the second camera is to provide redundancy for mission-critical optical navigation. Both imagers contain the Focal Plane Arrays (FPA) and filter wheel actuator with rectangular filters. Mounting Alignment ------------------------------------------------------------------------------ Refer to the latest version of the Psyche Frames Definition Kernel (FK) (see [3]) for the IMG reference frame definitions and mounting alignment information. Apparent FOV Layout ------------------------------------------------------------------------------ [TBD] -- to be confirmed with the imager team. This section provides a diagram illustrating the IMGA and IMGB apparent FOV layout in the corresponding reference frames. Pixel (0,0) is in the lower left corner of the image, and pixel (1600, 1200) is in the top right corner. +X, +Y, +Z axes are defined in the Psyche Frames Definition Kernel (FK) [3]. Per "Imager characteristics and resource requirements" section in [4], each imager has a field of view of 4.6 deg x 3.4 deg, and a resolution of 1600 x 1200 pixels. | 4.6 deg | Boresight (+Z axis) |<----------------->| is into the page | | +Ximga ^ +Ximgb | | --- +---------|---------+ ^ | | | | | | | | | | | | | | | |3.4 deg 1200 | x-------------> | lines | +Zimga | +Yimga | | +Zimgb | +Yimgb | | | v | | --- (0,0)-----------------+ Pixel 1600 pixels/line Optical Parameters ------------------------------------------------------------------------------ The following IMGA and IMGB nominal first order optical parameters are, from [4]: ------------------------------------------------------------------------ parameter IMGA IMGB ------------------------------------------------------------------------ Focal Length, mm 148.0 148.0 f/ratio f/2.9 f/2.9 IFOV, rad/pixel 0.00005018 x 0.0000495 0.00005018 x 0.0000495 Field of view, deg 4.6 x 3.4 4.6 x 3.4 ------------------------------------------------------------------------ In reality, the pixels are not square, being slightly larger in the X direction than the Y direction. Focal lengths are also different for each filter. The keywords below provide the optical parameters for each imager. Angular size values are given in radians. Focal length is given in mm, and its uncertainty is 0.01 mm. The FOV is calculated from the focal length given here and the pixel dimensions specified in the "Imager characteristics and resource requirements" section of [4]; it does not include the radial distortion. The first vector element of the IFOV and FOV angular size keywords refers to the X direction, the second to the Y direction. IMGA filters \begindata INS-255110_FOCAL_LENGTH = ( 148.0 ) INS-255110_IFOV = ( 0.000050178, 0.000049451 ) INS-255110_FOV_ANGULAR_SIZE = ( 0.080285, 0.059341 ) INS-255110_F/RATIO = ( 2.9 ) \begintext IMGB filters \begindata INS-255130_FOCAL_LENGTH = ( 148.0 ) INS-255130_IFOV = ( 0.000050178, 0.000049451 ) INS-255130_FOV_ANGULAR_SIZE = ( 0.080285, 0.059341 ) INS-255130_F/RATIO = ( 2.9 ) \begintext CCD Parameters ------------------------------------------------------------------------------ The IMGA and IMGB use a CCD detector of the same type with the following nominal geometry parameters (see [4]). ------------------------------------------------------- parameter value ------------------------------------------------------- Pixel Size, microns 7.4 Detector Array Size ( 1600, 1200 ) Detector Array Center ( 799.5, 599.5 ) ------------------------------------------------------- The values are given in microns for PIXEL_SIZE keywords and in counts for PIXEL_SAMPLES, PIXEL_LINES, and CENTER keywords. IMGA filters \begindata INS-255110_PIXEL_SIZE = ( 7.4, 7.4 ) INS-255110_PIXEL_SAMPLES = ( 1600 ) INS-255110_PIXEL_LINES = ( 1200 ) INS-255110_CCD_CENTER = ( 799.5, 599.5 ) \begintext IMGB filters \begindata INS-255130_PIXEL_SIZE = ( 7.4, 7.4 ) INS-255130_PIXEL_SAMPLES = ( 1600 ) INS-255130_PIXEL_LINES = ( 1200 ) INS-255130_CCD_CENTER = ( 799.5, 599.5 ) \begintext Filter Parameters ------------------------------------------------------------------------------ This section contains IMGA and IMGB filter parameters. The following filter band center, band width, and effective wavelength (all in nm) data are taken from [4]. FWHM is the Full Width at Half Maximum. The effective wavelength is defined as the integral over the product of the wavelength and the solar spectrum, divided by the integral over the solar spectrum. ------------------------------------------- filter band FWHM effective # center wavelength ------------------------------------------- 1 540 280 540 ------------------------------------------- Given below are the center wavelength (BANDCENTER), the FWHM (BANDWIDTH), and effective wavelength (EFF_WAVELENGTH) for each of the filters, all in nm. The nominal values are those for filter 1. IMGA filters \begindata INS-255110_BANDCENTER = ( 540 ) INS-255110_BANDWIDTH = ( 280 ) INS-255110_EFF_WAVELENGTH = ( 540 ) \begintext IMGB filters \begindata INS-255130_BANDCENTER = ( 540 ) INS-255130_BANDWIDTH = ( 280 ) INS-255130_EFF_WAVELENGTH = ( 540 ) \begintext FOV Definitions ------------------------------------------------------------------------------ This section contains definitions for the IMGA and IMGB FOVs. These definitions are provided in a format required by the SPICE (CSPICE) function GETFOV (getfov_c). The set of assignments in the data section below defines the IMGA and IMGB FOVs with respect to the corresponding frames to be a rectangle with the corners defined by the first and last pixels of the first and last lines of the CCD and the boresight along the +Z axis. This FOV definition uses the FOV_ANGULAR_SIZE values from the ``Optical Parameters'' section above converted to degrees. IMGA filters \begindata INS-255110_FOV_FRAME = 'PSYC_IMGA' INS-255110_FOV_SHAPE = 'RECTANGLE' INS-255110_BORESIGHT = ( 0.0, 0.0, 148.0 ) INS-255110_FOV_CLASS_SPEC = 'ANGLES' INS-255110_FOV_REF_VECTOR = ( 0.0, 1.0, 0.0 ) INS-255110_FOV_REF_ANGLE = ( 2.3 ) INS-255110_FOV_CROSS_ANGLE = ( 1.7 ) INS-255110_FOV_ANGLE_UNITS = 'DEGREES' \begintext IMGB filters \begindata INS-255130_FOV_FRAME = 'PSYC_IMGB' INS-255130_FOV_SHAPE = 'RECTANGLE' INS-255130_BORESIGHT = ( 0.0, 0.0, 148.0 ) INS-255130_FOV_CLASS_SPEC = 'ANGLES' INS-255130_FOV_REF_VECTOR = ( 0.0, 1.0, 0.0 ) INS-255130_FOV_REF_ANGLE = ( 2.3 ) INS-255130_FOV_CROSS_ANGLE = ( 1.7 ) INS-255130_FOV_ANGLE_UNITS = 'DEGREES' \begintext End of IK file.