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 0.4 -- June 20, 2017 -- Marc Costa Sitja, ESAC/ESA Simon Lindsay, University of Leicester As an outcome of the first review of the kernel by the MIXS Instrument Team the MIXS-T FOV definition has been updated along with other details specified in [5]. Version 0.3 -- February 15, 2017 -- 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 5, 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 ESAC/ESA 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. 5. ``BepiColombo MIXS - SPICE kernels validation'', BC-MIX-TN-299, S. Lindslay, University of Leicester, Issue 1, Revision 0, 3rd May 2017. 6. E-mail communication ``RE: SPICE kernel feedback from MIXS'', S. Lindslay, University of Leicester, 5th June 2017. 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 ~210 mm, a focal length of 1 m and a FOV of 1.1 degrees. 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. While the MIXS-C detector comprises 64x64 pixels, MIXS-C histogram data is binned across all pixels, and all pixels have visibility of the whole FOV. Thus, here the MIXS-C detector is considered as if it comprised a single large pixel. Note that the pixel address is identifiable in pixel list data and that it is important to account for the different gain and offset of pixels when analysing such data. 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 | arcmin | 1 | 600 | |- - - - - - - - - - - - - - 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 | 1 Pixels per line | # | 64 | 1 Pixel pitch | micrometers | 300 | 19200 Peak quantum | % | ~100% | ~100% efficiency | | | Scale per pixel | arcmin | 1.0 | N/A Smear | | | At Periapsis | 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 Periapsis (*) | m/pixel | <1000 | N/A | | | (*) This spatial resolution is an optimum only achievable at high solar state. 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 1.1 degree. For MIXS-C, a MCP collimator is used to define a square FOV of ~10 degrees Full Width at Zero Maximum (FWZM) alsong the principal axes. This section provides a diagram illustrating the MIXS-T and MIXS-C apparent FOV layout in the corresponding reference frames. ^ +Zmixs-t | +Zmixs-c Pixel | (63,63)------|---------+ --- | | | ^ | | | | 1.1 deg | | | | (mixs-t) | | | | 64 lines +Ymixs-t, <------------x | | (MIXS-T) +Ymixs-c | +Xmixs-t, | | 1 line | +Xmixs-c | | (MIXS-C) | | | 10 deg | Pixel V (mixs-c) +-----------------(0,0) --- 64 pixels/line (MIXS-T) 1 pixel/line (MIXS-C) | 1.1 deg (mixs-t) | Boresight (+X 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 = ( 1.0 0.0 0.0 ) INS-121310_FOV_CLASS_SPEC = 'ANGLES' INS-121310_FOV_REF_VECTOR = ( 0.0 0.0 1.0 ) 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 [6]. \begindata INS-121320_FOV_FRAME = 'MPO_MIXS-T' INS-121320_FOV_SHAPE = 'RECTANGLE' INS-121320_BORESIGHT = ( 1.0 0.0 0.0 ) INS-121320_FOV_CLASS_SPEC = 'ANGLES' INS-121320_FOV_REF_VECTOR = ( 0.0 0.0 1.0 ) INS-121320_FOV_REF_ANGLE = ( 0.55 ) INS-121320_FOV_CROSS_ANGLE = ( 0.55 ) INS-121320_FOV_ANGLE_UNITS = 'DEGREES' \begintext Optical Parameters --------------------------------------------------------------------------- [TBD] \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 = ( 0.000299987 ) \begintext Detector Parameters --------------------------------------------------------------------------- [TBD] \begindata INS-121310_PIXEL_SIZE = ( 19200, 19200 ) 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 --------------------------------------------------------------------------- [TBD] 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.