KPL/IK SPICE Instrument Kernel =========================================================================== This instrument kernel (I-kernel) briefly describes and contains orientative information of the Field-of-View (FoV) and/or Field-of-Regard (FoR) of and the line of sight (boresight) of the Spectral Imaging of the Coronal Environment (SPICE) sensors. DISCLAIMER: This I-kernel should not be used as a reference for the instrument nor for data analysis for the FoVs will not be updated to reflect best known / calibrated FoVs, nor variation according to mode. Version and Date ----------------------------------------------------------------------------- Version 0.0 -- May 16, 2017 -- Marc Costa Sitja, ESAC/ESA Preliminary Version. References ----------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading''. 2. ``Frames Required Reading''. 3. ``C-Kernel Required Reading''. 4. Solar Orbiter Spacecraft Frames Definition Kernel. 5. ``SPICE Experiment Interface Definition – Part B (EID-B)'', SPICE-RAL-RS-0001, P. Eccleston, Issue 6, Revision 0, 7th October 2015. Contact Information ----------------------------------------------------------------------------- If you have any questions regarding this file contact SPICE support at ESAC: Marc Costa Sitja (+34) 91-8131-457 mcosta@sciops.esa.int, esa_spice@sciops.esa.int or the Solar Orbiter Science Operations Center at ESAC: sol_soc@esa.int 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 [2] 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 Naming Conventions ----------------------------------------------------------------------------- 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 SOLO instrument ID code, constructed using the spacecraft ID number (-144) followed by the NAIF three digit ID number for one of the SPICE data item. These IDs are as follows Instrument name ID -------------------- ------- SOLO_SPICE_SW -144810 SOLO_SPICE_LW -144820 The remainder of the name is an underscore character followed by the unique name of the data item. For example, the SPICE boresight direction in the SOLO_SPICE_SW_OPT frame (see [2]) is specified by: INS-144810_BORESIGHT The upper bound on the length of the name of any data item identifier is 32 characters. If the same item is included in more than one file, or if the same item appears more than once within a single file, the latest value supersedes any earlier values. Overview ----------------------------------------------------------------------------- From [5]: SPICE is a high resolution imaging spectrometer operating at ultraviolet wavelengths. It will address the key science goals of the Solar Orbiter mission, by providing the quantitative knowledge of the physical state and composition of the plasmas at the solar source region and investigating the links between the solar surface, corona and inner heliosphere. The EUV wavelength region 70.2 - 105 nm observed by SPICE is dominated by emission lines from a wide range of ionized atoms formed in the Sun's atmosphere at temperatures from 10.000 to 10 million K. SPICE will measure plasma density and temperature, flow velocities, the presence of plasma turbulence and composition of the source region plasma. It will be observing, at all latitudes, the energetics, dynamics and fine-scale structure of the Sun’s magnetized atmosphere. SPICE will remotely determine plasma properties on the Sun and provide understanding of the linkage between in-situ measurements of solar wind streams using the suite of plasma instruments on Solar Orbiter and remote imaging of their source regions on and near the Sun. Instrument Design: ~~~~~~~~~~~~~~~~~~ The SPICE instrument is an imaging spectrograph which records high resolution EUV spectra of the Sun. The SPICE optical design is based on the comprehensive work carried out during the earlier phases of the project. The light enters the instrument through the entrance aperture then an image is formed at the slit by the off-axis parabola. The slit defines the portion of the solar image that is allowed to pass onto a concave Toroidal Variable Line Space (TVLS) grating, which disperses, magnifies, and reimages incident radiation onto two detectors. The two wavebands cover the same one-dimensional spatial field, and are recorded simultaneously. The instrument contains four mechanisms: - The SPICE Door Mechanism (SDM) which can be actuated to provide a contamination tight seal of the entrance aperture during non-operational periods (both during ground handling when under purge and non-operational periods in flight). - The telescope mirror is mounted to a two-axis mechanism (tilt and focus), the scan focus mechanism (SFM), that is used to direct different portions of the solar image onto the selected entrance slit and to focus the telescope relative to the entrance slit. The image of the Sun is repeatedly scanned across the entrance slit an area of the Sun. During each scan the image of the Sun is stepped across the entrance slit in increments equal to the selected slit width, such that the region of interest is completely sampled. - A slit change mechanism (SCM) provides four interchangeable slits of different widths, one of which can be selected depending upon the science activities to be conducted. In the nominal design these slits have a 2'', 4'', 6'' and 30'' width on the external field of view. - A vacuum door mechanism on the Detector Assembly (DA Door). The micro-channel plate and image intensifier used to translate the incident EUV photons into visible light photons which can be detected by the detectors must be maintained either at vacuum or in zero humidity during ground handling. Therefore the detector assembly contains a door mechanism which is only opened during vacuum testing on ground, and opened finally once on-orbit. Mounting Alignment ----------------------------------------------------------------------------- Refer to the latest version of the Solar Orbiter Frames Definition Kernel (FK) [4] for the SPICE reference frame definitions and mounting alignment information. SPICE Apparent Field-of-View Layout ----------------------------------------------------------------------------- For SPICE the FoV in the direction of the scan is actually the Field of Regard (FoR) defined by the full theoretical movement of the scan mechanism. This applies to both the SW and LW sensors. This section provides a diagram illustrating the SPICE apparent FoR layout in the corresponding reference frames. ^ +Yspice | | --- +---------|---------+ ^ | | | | | | | | | | | | | | | | 4 arcmin | x-------------> +Zspice | | +Xspice | | | | | | | V | | --- +-------------------+ | 10 arcmin | Boresight (+X axis) |<----------------->| is into the page | | FOV Definition --------------------------------------------------------------------------- This section contains definitions for the SPICE apparent FOVs. These definitions are provided in the format required by the SPICE TOOLKIT function GETFOV. The FoV definition corresponds to the NAIF Body Names: SOLO_SPICE_SW and SOLO_SPICE_LW. \begindata INS-144810_FOV_FRAME = 'SOLO_SPICE_SW_OPT' INS-144810_FOV_SHAPE = 'RECTANGLE' INS-144810_BORESIGHT = ( -1.000000 0.000000 0.000000 ) INS-144810_FOV_CLASS_SPEC = 'ANGLES' INS-144810_FOV_REF_VECTOR = ( 0.000000 0.000000 1.000000 ) INS-144810_FOV_REF_ANGLE = ( 0.0666667 ) INS-144810_FOV_CROSS_ANGLE = ( 0.1666667 ) INS-144810_FOV_ANGLE_UNITS = 'DEGREES' INS-144820_FOV_FRAME = 'SOLO_SPICE_LW_OPT' INS-144820_FOV_SHAPE = 'RECTANGLE' INS-144820_BORESIGHT = ( -1.000000 0.000000 0.000000 ) INS-144820_FOV_CLASS_SPEC = 'ANGLES' INS-144820_FOV_REF_VECTOR = ( 0.000000 0.000000 1.000000 ) INS-144820_FOV_REF_ANGLE = ( 0.0666667 ) INS-144820_FOV_CROSS_ANGLE = ( 0.1666667 ) INS-144820_FOV_ANGLE_UNITS = 'DEGREES' \begintext Platform ID ----------------------------------------------------------------------------- This number is the NAIF instrument ID of the platform on which the channels are mounted. For all channels this platform is the spacecraft. \begindata INS-144900_PLATFORM_ID = ( -144000 ) \begintext End of IK file.