KPL/IK PFS Instrument kernel =========================================================================== This instrument kernel (I-kernel) contains Venus Express Planetary Fourier Spectrometer (PFS) optics, detector, and FOV parameters. Version and Date --------------------------------------------------------------------------- Version 0.1 -- October 16, 2018 -- Marc Costa Sitja, ESAC/ESA Updated the boresight definition (to unitary) for VEX_PFS_LWC in order to avoid an error using GFTFOV with SPICE Toolkit versions earlier than N067. Version 0.0 -- November 22, 2005 -- Jorge Diaz del Rio, RSSD/ESA Preliminary Version. Pending review from PFS Team. References --------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading'', NAIF Document No.____ 2. ``C-kernel Required Reading'', NAIF Document No.____ 3. ``PFS Instrument Description'' MEX-CNR-IQAR-02, November 15, 2001 4. Venus Express Frames Definition Kernel (FK), latest version. 5. ``PFS for Venus Express'' Delta Documentation 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 also be used if the file contains instrument field-of-view (FOV) specifications. 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 VEX instrument ID code, constructed using the spacecraft ID number (-248), followed by the NAIF three digit ID number for PFS Short Wave Channel (SWC), 320, or Long Wave Channel (LWC), 330. These IDs are defined in [4] as follows: Instrument name ID -------------------- ------- VEX_PFS_BASE -248300 VEX_PFS_SCANNER -248310 VEX_PFS_LWC -248320 VEX_PFS_SWC -248330 The remainder of the keyword is an underscore character followed by the unique name of the data item. For example, the number of pixels of the SWC is specified by INS-248320_NUMBER_OF_PIXELS 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. Instrument Overview -------------------------------------------------------- From [TBD]: "PFS description. To be copied from TBD source provided by the PFS team." Mounting Alignment -------------------------------------------------------- Refer to the latest version of the s Express Frames Definition Kernel (FK) [4] for the PFS reference frame definitions and mounting alignment information. Optics and Detector Parameters -------------------------------------------------------- This section contains assignments specifying the PFS SWC and LWC optics and detector parameters. The following PFS SWC and LWC optical and detector shape/size parameters are included in the data section below, taken from [3] (nominal values) and [5]: ----------------------------------------------------------------- parameter SWC LWC ----------------------------------------------------------------- Focal Length, mm 20.0 20.0 Detector shape square circle Detector size, mm 0.7 1.4 Number of pixels 1 1 IFOV, rad/pixel nominal 0.035 0.070 actual (FWHM) 0.027925268 0.048869218 ----------------------------------------------------------------- These values are provided in the assignments below, with the same units as in the table. \begindata INS-248320_FOCAL_LENGTH = ( 20.0 ) INS-248320_DETECTOR_SIZE = ( 0.7 ) INS-248320_NUMBER_OF_PIXELS = ( 1 ) INS-248320_IFOV = ( 0.027925268 ) INS-248330_FOCAL_LENGTH = ( 20.0 ) INS-248330_DETECTOR_SIZE = ( 1.4 ) INS-248330_NUMBER_OF_PIXELS = ( 1 ) INS-248330_IFOV = ( 0.048869218 ) \begintext FOV Definitions --------------------------------------------------------------------------- This section contains assignments defining the PFS SWC and LWC FOVs. These definitions are based on the PFS detector and optics parameters provided in the previous section and are provided in a format consistent with/required by the SPICE (CSPICE) function GETFOV (getfov_c). SWC The SWC FOV is defined as a square pyramid with a half angle of 0.8 degress with respect to the VEX_PFS_SWC frame (see [4]). The boresight vector, along the +Z axis of the frame, was scaled to be equal to the focal length. The cross-reference vector is a unit along the +X axis of the frame. \begindata INS-248320_FOV_FRAME = 'VEX_PFS_SWC' INS-248320_FOV_SHAPE = 'RECTANGLE' INS-248320_BORESIGHT = ( 0.0 0.0 20.0 ) INS-248320_FOV_CLASS_SPEC = 'ANGLES' INS-248320_FOV_REF_VECTOR = ( 1.0 0.0 0.0 ) INS-248320_FOV_REF_ANGLE = ( 0.8 ) INS-248320_FOV_CROSS_ANGLE = ( 0.8 ) INS-248320_FOV_ANGLE_UNITS = 'DEGREES' \begintext LWC The LWC FOV is defined as a cone with a half angle of 1.4 degrees with respect to the VEX_PFS_LWC frame (see [4]). The boresight vector, along the +Z axis of the frame, was scaled to be equal to the focal length. The cross-reference vector is a unit vector along the +X axis the frame. \begindata INS-248330_FOV_FRAME = 'VEX_PFS_LWC' INS-248330_FOV_SHAPE = 'CIRCLE' INS-248330_BORESIGHT = ( 0.0 0.0 1.0 ) INS-248330_FOV_CLASS_SPEC = 'ANGLES' INS-248330_FOV_REF_VECTOR = ( 1.0 0.0 0.0 ) INS-248330_FOV_REF_ANGLE = ( 1.4 ) INS-248330_FOV_ANGLE_UNITS = 'DEGREES' \begintext Spectral Parameters --------------------------------------------------------------------------- This section contains assignments specifying PFS SWC and LWC spectral resolution parameters. The following PFS SWC and LWC spectral resolution parameters are included in the data section below, taken from [3] (nominal values): ----------------------------------------------------------------- parameter SWC LWC ----------------------------------------------------------------- Spectral range, microns nominal 0.9 - 5.0 5 - 45 Number of spectral bins 16384 4096 ----------------------------------------------------------------- These values are provided in the assignments below, with the same units as in the table. \begindata INS-248320_SPECTRAL_RANGE = ( 0.9, 5.0 ) INS-248320_NUMBER_OF_BINS = ( 16384 ) INS-248330_SPECTRAL_RANGE = ( 5.0, 45.0 ) INS-248330_NUMBER_OF_BINS = ( 4096 ) \begintext Timing --------------------------------------------------------------------------- This section specified the timing delay that should be considered in the data processing. For each measurement (spectrum) the SCET time provided in the data corresponds to the exact time when the measurement starts. To this time, one has to add a delay of 0.45 seconds due to time needed to accelerate the double pendulum and reach the operational velocity used to scan all the spectrum. The delay value in seconds is provided in the assignments below. \begindata INS-248320_TIMING_DELAY = ( 0.45 ) INS-248330_TIMING_DELAY = ( 0.45 ) \begintext Platform ID --------------------------------------------------------------------------- This number is the NAIF instrument ID of the platform on which the instrument is mounted. PFS (and all its parts) is mounted directly on the spacecraft. \begindata INS-248300_PLATFORM_ID = ( -248000 ) INS-248310_PLATFORM_ID = ( -248000 ) INS-248320_PLATFORM_ID = ( -248000 ) INS-248330_PLATFORM_ID = ( -248000 ) \begintext