KPL/IK HERA HyperScout Hyperspectral Imager Instrument kernel ============================================================================== This instrument kernel (I-kernel) contains the HyperScout hyperspectral imager (HSH) optics, detector, and field-of-view parameters. Version and Date ------------------------------------------------------------------------------ Version 0.2 -- February 5, 2025 -- Alfredo Escalante Lopez, ESAC/ESA Corrected field-of-view aperture angles for correct orientation. Added optical and detector parameters and descriptions. Version 0.1 -- September 21, 2023 -- Ricardo Valles, ESAC/ESA Updated Hera ID according to one provided by DSN and confirmed by FDy: from -999 to -91. Version 0.0 -- November 8, 2021 -- Alfredo Escalante Lopez, ESAC/ESA Initial release. References ------------------------------------------------------------------------------ 1. ``Kernel Pool Required Reading'' 2. ``C-kernel Required Reading'' 3. Hera Frames Definition Kernel (FK), latest version. 4. Hera Payload Interfaces, Issue 1.7, 14 June 2019. Contact Information ----------------------------------------------------------------------------- If you have any questions regarding this file contact the ESA SPICE Service at ESAC: Alfredo Escalante Lopez (+34) 91-8131-429 spice@cosmos.esa.int or NAIF at JPL: Boris Semenov +1 (818) 354-8136 Boris.Semenov@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 [1]. All keywords referencing values in this I-kernel start with the characters `INS' followed by the NAIF HERA instrument ID code, constructed using the spacecraft ID number (-91) followed by the NAIF three digit ID number. The ID numbers are defined in [3] as follows: Instrument name ID -------------------- ------- HERA_HSH -91400 The remainder of the keyword is an underscore character followed by the unique name of the data item. For example, the boresight of HSH is specified by INS-91400_BORESIGHT 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 ------------------------------------------------------------------------------ From [4]: HyperScout-H will observe the Dimorphos asteroid in a range of colours far beyond the limits of the human eye and help determine the asteroid's mineral makeup. The hyperspectral imager covers the 650–950 nm wavelength range, with colours coded so that blue represents the shortest wavelengths and red represents the longest. The shoebox-sized imaging spectrometer was provided by cosine remote sensing in the Netherlands. These are some specification of the HS-H: ------------------------------------------- Specification ------------------------------------------- Pixel pitch 5.5 um Detector Resolution 2048 x 1088 pixels Macro pixels 409 x 217 pixels Spectral range 665 - 975 nm Spectral Bands 25 Spectral Resolution 8 - 27 nm Spatial Resolution 26 cm @ 2 km Aperture diameter 10.3125 mm Focal length 41.25 mm IFOV, rad/pixel 0.0001354 Field of view (paraxial) 15.5 x 8.3 degrees Field of view (real) 15.9 x 9.9 degrees ------------------------------------------- Mounting Alignment ------------------------------------------------------------------------------ Refer to the latest version of the HERA Frames Definition Kernel (FK) [4] for the HSH reference frame definitions and mounting alignment information. Apparent FOV Layout ------------------------------------------------------------------------------ This section provides a diagram illustrating the HSH apparent FOV layout in the corresponding reference frames. Pixel (0,0) is in the lower left corner of the image, and pixel (1000, 2000) is in the top right corner. +X, +Y, +Z axes are defined in the HERA Frames Definition Kernel (FK) [3]. | 9.9 deg | Boresight (+Z axis) |<---------->| is into the page | | 1088 pixels/line --- +------------+ ^ | | | | +Zhsh | |15.9 deg 2048 | x---------> +Xhsh | lines | | | v | | | --- (0,0)----|-----+ Pixel | v +Yhsh Optical Parameters ------------------------------------------------------------------------------ HS-H is counts with 25 spectral bands covering the wavelength range from 665 to 975 nm. Each macropixel, made of a 5 x 5 matrix of pixels, records the signal across 25 different narrow bands, with each band corresponding to a pixel. \begindata INS-91400_BANDCENTER = ( 820.0 ) INS-91400_BANDWIDTH = ( 310.0 ) \begintext Detector Parameters ------------------------------------------------------------------------------ The values are given in micrometers for PIXEL_SIZE, microradians for IFOV, pixels for PIXEL_SAMPLES, PIXEL_LINES, and for CCD_CENTER. The keywords PIXEL_SAMPLES and PIXEL_LINES respectively correspond to detector columns and rows. Although HS-H uses a CMOS sensor, the keyword CCD_CENTER is maintained for historical and compatibility reasons. \begindata INS-91400_PIXEL_SAMPLES = ( 2048 ) INS-91400_PIXEL_LINES = ( 1088 ) INS-91400_PIXEL_SIZE = ( 5.5 ) INS-91400_CCD_CENTER = ( 1024.5, 544.5 ) INS-91400_IFOV = ( 135.4 ) \begintext FOV Definitions ------------------------------------------------------------------------------ This section contains definitions for the HSH 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 HSH 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. \begindata INS-91400_NAME = 'HERA_HSH' INS-91400_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-91400_FOV_FRAME = 'HERA_HSH' INS-91400_FOV_SHAPE = 'RECTANGLE' INS-91400_FOV_CLASS_SPEC = 'ANGLES' INS-91400_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-91400_FOV_REF_ANGLE = ( 4.95 ) INS-91400_FOV_CROSS_ANGLE = ( 7.95 ) INS-91400_FOV_ANGLE_UNITS = 'DEGREES' \begintext Optical Distortion ------------------------------------------------------------------------------ TBD. End of IK file.