KPL/IK MIXS Instrument kernel =========================================================================== This instrument kernel (I-kernel) contains BepiColombo MIXS optics, detector, and field-of-view parameters for the two telescopes (MIXS-T and MIXS-C) that made up the instrument. Version and Date --------------------------------------------------------------------------- Version 0.3 -- February 15, 2016 -- Marc Costa Sitja, ESAC/ESA Updated instrument description and added main parameters table. Pending review from BepiColombo SGS and MIXS instrument team. Version 0.2 -- July 05, 2016 -- Marc Costa Sitja, ESAC/ESA Updated BEPICOLOMBO MPO IDs from -69 to -121. Removed kernel name and version assignment. Version 0.1 -- February 18, 2013 -- R. Moissl, ESAC/ESA Updated ID's, Names and cleaned up some parts Version 0.0 -- May 29, 2009 -- J. Vazquez/J. McAuliffe, ESAC/ESA Initial draft. References --------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading'' 2. ``C-kernel Required Reading'' 3. ``MIXS EID, Part B'', BC-EST-RS-2517 Issue 1, 11th July 2012 4. BepiColombo Frames Definition Kernel (FK), latest version. Implementation Notes ----------------------------------------------------------------------------- This file is used by the SPICE system as follows: programs that make use of this frame kernel must "load" the kernel normally during program initialization. Loading the kernel associates the data items with their names in a data structure called the "kernel pool". The SPICELIB routine FURNSH loads a kernel into the pool as shown below: FORTRAN: (SPICELIB) CALL FURNSH ( frame_kernel_name ) C: (CSPICE) furnsh_c ( frame_kernel_name ); IDL: (ICY) cspice_furnsh, frame_kernel_name MATLAB: (MICE) cspice_furnsh ( 'frame_kernel_name' ) PYTHON: (SPICEYPY)* furnsh( frame_kernel_name ) In order for a program or routine to extract data from the pool, the SPICELIB routines GDPOOL, GIPOOL, and GCPOOL are used. See [1] for more details. This file was created and may be updated with a text editor or word processor. * SPICEPY is a non-official, community developed Python wrapper for the NAIF SPICE toolkit. Its development is managed on Github. It is available at: https://github.com/AndrewAnnex/SpiceyPy 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 BepiColombo instrument ID code, constructed using the spacecraft ID number (-121) followed by the NAIF three digit ID number for MIXS-C (310) or MIXS-T (320). These IDs are defined in [4] as follows: Instrument name ID -------------------- ------- MPO_MIXS_C -121310 MPO_MIXS_T -121320 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 MIXS-T is specified by INS-121310_FOCAL_LENGTH 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 [3]: The primary surface science objectives of the MIXS instrument are, in keeping with the BepiColombo Science Requirements document, to: - produce global elemental abundance maps of key elements to an accuracy of 5-50% depending on concentration and the element under examination, - perform spatially resolved measurements of these elemental abundances, achieving high spatial resolution mapping where solar conditions permit, - confirm that the auroral zone, where energetic particles interact with the surface, is an intense source of continuum and line X-rays. The MIXS instrument contains two parallel telescopes, designed to map the X-ray emission from Mercury at two angular resolutions. The narrow-field telescope (MIXS-T) uses a grazing incidence optic with a 1 degree field-of-view (FOV) and an imaging detector with 64 x 64 pixels. The wide-field telescope (MIXS-C) uses a collimator to define a FOV of ~10 degrees Full Width at Zero Maximum (FWZM). Its detector is identical to MIXS-T, but as the collimator has no imaging capability, the pixels are aggregated into a single output. The optical axes are aligned with the nadir-pointing axis of the spacecraft. MIXS-T: ~~~~~~~ The front element of the telescope is an X-ray mirror constructed from 36 MCP elements, with an overall diameter of ~21 cm, a focal length of 1 m and a FOV of ~1 degree. At the focal plane is a focal plane assembly (FPA) containing a silicon macropixel array X-ray detector, 1.9 cm square, and cooled to below -45 degrees C. The detector has 64 x 64 pixels and is sensitive to X-rays in the energy range <0.5 to >7.5 keV. It is photon-counting and energy-resolving, giving an electrical signal proportional to the energy of individual photons with a resolution of ~200 eV FWHM at end of life. At the start of the mission the energy resolution is expected to be significantly better. MIXS-C: ~~~~~~~ A MCP collimator, 8 cm square, is used to define a FOV of ~10 degrees FWZM. 55 cm behind the collimator is a focal plane assembly identical to that on MIXS-T. The instrument contains 2 telescopes, which are located side-by-side, with the optical axes parallel. The FPAs are identical, but at different distances from the optics. Each FPA contains the detector, as previously described, together with front-end electronics, which provides control signals to the detector, digitises the output, and thresholds the signal to detect photons. The pixel positions and pulse height (X-ray energy) of the detected photons are sent to a common data processing unit (DPU) via a serial communications channel. In front of each detector is a light filter (the detectors are also sensitive to light). The following table provides the principal optical, performance and resolution parameters of MIXS: Parameter | Units | MIXS-T | MIXS-C -------------------------+--------------+--------------+------------ Optics | | | | | | Aperture | mm | 210 diam. | 80 x 80 Focal length | mm | 1000 | 550 Focal number | | 4.8 | N/A Field of view | degrees | +/- 0.55 | +/- 5 Central obstruction | % | 4 | N/A Pixel IFOV | microrad | 1 | N/A | |- - - - - - - - - - - - - - Spectral range | keV | ~0.5 - 7.5 Mirror Material | | Ir coated glass. Note the | | inner ring MCPs for | | MIXS-T are bare glass | | Sensor (CCD/APS) | | | | Pixel lines | # | 64 Pixels per line | # | 64 Pixel pitch | microrad | 300 Peak quantum | % | ~100% efficiency | |- - - - - - - - - - - - - - Scale per pixel | armcin | 1.0 | N/A Smear | | | At Periherm | px/s | 20 | N/A Exposure time | ms | 100 | 4000 | |- - - - - - - - - - - - - - Imaging sequence | s | Continuous duration | | (Photon Counting) Energy Resolution | eV FWHM | <200 | |- - - - - - - - - - - - - - Resolution | | | | | | Angular resolution | arcmin | ~9 | N/A Spatial resolution | | | At Periherm | m/pixel | <1000 | N/A | | | Mounting Alignment --------------------------------------------------------------------------- Refer to the latest version of the BepiColombo Frames Definition Kernel (FK) [4] for the MIXS reference frame definitions and mounting alignment information. MIXS Apparent Field-of-View Layout --------------------------------------------------------------------------- For MIXS-T, the front element of the telescope is an X-ray mirror with a a FOV of ~1 degree. For MIXS-T, a MCP collimator, is used to define a FOV of ~10 degrees Full Width at Zero Maximum (FWZM). This section provides a diagram illustrating the MIXS-T and MIXS-C apparent FOV layout in the corresponding reference frames. ^ +Xmixs-t | +Xmixs-c Pixel | --- (1,1)-------|---------+ ^ | | | | 1 deg | | | 64 lines | (mixs-t) | | | (MIXS-T) | | | | 1 line | | x-------------> +Ymixs-t (MIXS-C) | | +Zmixs-t | +Ymixs-c | | +Zmixs-c | | 10 deg | | V (mixs-c) | | --- +-------------------+ 64 pixels/line (MIXS-T) 1 pixel/line (MIXS-C) | 1 deg (mixs-t) | Boresight (+Z axis) |<----------------->| is into the page | 10 deg (mixs-c) | FOV Definitions --------------------------------------------------------------------------- This section contains definitions for the MIXS-C and MIXS-T FOVs. These definitions are provided in the format required by the SPICE TOOLKIT function GETFOV. MIXS-C FOV: ~~~~~~~~~~~ The set of assignments in the data section below defines the MIXS-C FOV with respect to the MPO_MIXS-C frame 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 of the instrument frame. This FOV definition uses angular extent style specification with the cross and along track angular sizes taken from the ``Optics Parameters'' section above. Please note that the FOV reference and cross angles are defined with half angle values. The following FOV definition corresponds to the NAIF Body Name: MPO_MIXS-C. \begindata INS-121310_FOV_FRAME = 'MPO_MIXS-C' INS-121310_FOV_SHAPE = 'RECTANGLE' INS-121310_BORESIGHT = ( 0.0 0.0 1.0 ) INS-121310_FOV_CLASS_SPEC = 'ANGLES' INS-121310_FOV_REF_VECTOR = ( 1.0 0.0 0.0 ) INS-121310_FOV_REF_ANGLE = ( 5.0 ) INS-121310_FOV_CROSS_ANGLE = ( 5.0 ) INS-121310_FOV_ANGLE_UNITS = 'DEGREES' \begintext MIXS-T FOV: ~~~~~~~~~~~ The set of assignments in the data section below defines the MIXS-T FOV with respect to the MPO_MIXS-T frame 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 of the MPO_MIXS_T frame. This FOV definition uses angular extent style specification with the cross and along track angular sizes taken from the ``Optics Parameters'' section above. Please note that the FOV reference and cross angles are defined with half angle values. The following FOV definition corresponds to the NAIF Body Name: MPO_MIXS-T. \begindata INS-121320_FOV_FRAME = 'MPO_MIXS-T' INS-121320_FOV_SHAPE = 'RECTANGLE' INS-121320_BORESIGHT = ( 0.0 0.0 1.0 ) INS-121320_FOV_CLASS_SPEC = 'ANGLES' INS-121320_FOV_REF_VECTOR = ( 1.0 0.0 0.0 ) INS-121320_FOV_REF_ANGLE = ( 0.5 ) INS-121320_FOV_CROSS_ANGLE = ( 0.5 ) INS-121320_FOV_ANGLE_UNITS = 'DEGREES' \begintext Optical Parameters --------------------------------------------------------------------------- [TBW] \begindata INS-121310_FOCAL_LENGTH = ( 550.0 ) INS-121310_F/RATIO = ( 0.145455 ) INS-121310_FOV_ANGULAR_SIZE = ( 0.17453293, 0.17453293 ) INS-121310_IFOV = ( 0.17453293 ) INS-121320_FOCAL_LENGTH = ( 1000.0 ) INS-121320_F/RATIO = ( 4.76190 ) INS-121320_FOV_ANGULAR_SIZE = ( 0.017453293, 0.017453293 ) INS-121320_IFOV = ( 0.000272708 ) \begintext Detector Parameters --------------------------------------------------------------------------- [TBW] \begindata INS-121310_PIXEL_SIZE = ( 300, 300 ) INS-121310_PIXEL_SAMPLES = ( 1 ) INS-121310_PIXEL_LINES = ( 1 ) INS-121310_CCD_CENTER = ( 0.5, 0.5 ) INS-121320_PIXEL_SIZE = ( 300, 300 ) INS-121320_PIXEL_SAMPLES = ( 64 ) INS-121320_PIXEL_LINES = ( 64 ) INS-121320_CCD_CENTER = ( 31.5, 31.5 ) \begintext Optical Distortion --------------------------------------------------------------------------- [TBW] Platform ID --------------------------------------------------------------------------- This number is the NAIF instrument ID of the platform on which the instrument(s) are mounted. For both channels this platform is the spacecraft. \begindata INS-121310_PLATFORM_ID = ( -121000 ) INS-121320_PLATFORM_ID = ( -121000 ) \begintext End of IK file.