KPL/IK PHI 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 Solar Orbiter Polarimetric and Helioseismic Imager (PHI) 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. ``SO/PHI Polarimetric and Helioseismic Imager for Solar Orbiter - Experiment Interface Document Part B'', SOL-PHI-MPS-MN1400-IF-2, PHI Instrument Team / J. Woch, Issue 3, Revision 0, 18th November 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 PHI data item. These IDs are as follows Instrument name ID -------------------- ------ SOLO_PHI_FDT -144530 SOLO_PHI_HRT -144530 The remainder of the name is an underscore character followed by the unique name of the data item. For example, the PHI boresight direction in the SOLO_PHI frame (see [2]) is specified by: INS-144530_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]: PHI will address and resolve basic questions in solar physics by studying the Sun at high resolution from close up and from high latitudes up to 35 deg. PHI science will make full use of the unique trajectory of the Solar Orbiter mission and will provide data that cannot otherwise be obtained. PHI will provide maps of the magnetic vector and of the line-of-sight (LOS) velocity in the solar photosphere. It will thus probe the deepest layers of the Sun (including the solar interior using helioseismology) of all the instruments on Solar Orbiter. Since the magnetic field anchored at the solar surface produces most of the structures and energetic events in the upper solar atmosphere and significantly influences the heliosphere, PHI plays a key role in reaching the science goals of Solar Orbiter. Extrapolations of the magnetic field observed by PHI into the Sun’s upper atmosphere and heliosphere will provide the information needed for other remote-sensing and in-situ instruments to analyse and understand the data recorded by them in a proper physical context. Measurement Principle: ~~~~~~~~~~~~~~~~~~~~~~ PHI is a diffraction limited, wavelength tunable, quasi-monochromatic, polarization sensitive imager. These capabilities are needed to infer the magnetic field and line-of-sight (LOS) velocity of the region targeted by the S/C. The PHI instrument consists of the following 5 units: - High Resolution Telescope (HRT) Heat Rejecting Entrance Window (HREW) - Full Disk Telescope (FDT) HREW - Optics Unit (O-Unit) - Electronics Unit (E-Unit) - Harness The High Resolution Telescope (HRT) will provide a restricted FOV of 16.8 arcmin squared and achieve a spatial resolution that, near the closest perihelion pass, will be about 200 km on the Sun. The Full Disk Telescope (FDT), with a FOV of 2 deg and a pixel size of 725 km (at 0.28 AU), will provide a complete view of the full solar disk during all orbital phases. The two telescopes are used sequentially and their selection is made by a Feed Selection Mechanism (FSM). An internal Image Stabilization System (ISS) is necessary to guarantee the required image stability. A Correlation Tracker (CT) provides the necessary correction signals to an internal tip-tilt mirror. In order to limit the amount of light entering the instrument, two Heat Rejecting Entrance Windows (HREWs), one for each telescope, are mounted at a middle position in the feedthroughs within the S/C heat-shield. Polarization analysis is based on sequential polarization modulation and demodulation of the resulting intensity differences (differential photometry). Each telescope uses its own Polarization Modulation Package (PMP). For the spectral analysis, PHI will use an order-sorting filter to isolate a bandpass of the order of 100 mAms. The FilterGraph (FG) contains a filter system consisting of one Lithium Niobate (LiNbO3) etalon located inside a temperature-stabilized oven. The etalon is commercially available and have been developed and qualified in the past for solar magnetographs (in particular the stratospheric balloon-borne Sunrise/IMaX instrument). The FG extracts a spectral portion of the light inside the selected science spectral line (FeI 6173 Ams) and at a nearby continuum point. The FG provides a tuning range of +/-0.53 Ams which is required for compensating the S/C radial velocity of +/-26 kms-1 plus the range required to scan the spectral line (~400 mAms, depending on the observing mode). Finally, the transmitted image reaches the Focal Plane Assembly (FPA) with a 2048 x 2048 pixel APS detector. Mounting Alignment ----------------------------------------------------------------------------- Refer to the latest version of the Solar Orbiter Frames Definition Kernel (FK) [4] for the PHI reference frame definitions and mounting alignment information. PHI Apparent Field-of-View Layout ----------------------------------------------------------------------------- This section provides a diagram illustrating the EUI FSI, EUI HRI LYA and EUV apparent FOV layout in the corresponding reference frames. ^ +Yphi | | --- +---------|---------+ ^ | | | | 2 degrees | | | | (fdt) | | | | | | | | | x-------------> +Zphi | | +Xphi | | | | | 0.28 degrees | | V (hrt) | | --- +-------------------+ | 2 degrees (fdt) | Boresight (+X axis) |<----------------->| is into the page | 0.28 degrees (hrt)| FOV Definition --------------------------------------------------------------------------- This section contains definitions for the PHI apparent FOVs. These definitions are provided in the format required by the SPICE TOOLKIT function GETFOV. The FoV definitions correspond to the NAIF Body Names: SOLO_PHI_FDT, and SOLO_PHI_HRT. \begindata INS-144510_FOV_FRAME = 'SOLO_PHI_FDT_OPT' INS-144510_FOV_SHAPE = 'RECTANGLE' INS-144510_BORESIGHT = ( -1.000000 0.000000 0.000000 ) INS-144510_FOV_CLASS_SPEC = 'ANGLES' INS-144510_FOV_REF_VECTOR = ( 0.000000 0.000000 1.000000 ) INS-144510_FOV_REF_ANGLE = ( 1.000000 ) INS-144510_FOV_CROSS_ANGLE = ( 1.000000 ) INS-144510_FOV_ANGLE_UNITS = 'DEGREES' INS-144520_FOV_FRAME = 'SOLO_PHI_HRT_OPT' INS-144520_FOV_SHAPE = 'RECTANGLE' INS-144520_BORESIGHT = ( -1.000000 0.000000 0.000000 ) INS-144520_FOV_CLASS_SPEC = 'ANGLES' INS-144520_FOV_REF_VECTOR = ( 0.000000 0.000000 1.000000 ) INS-144520_FOV_REF_ANGLE = ( 0.140000 ) INS-144520_FOV_CROSS_ANGLE = ( 0.140000 ) INS-144520_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-144500_PLATFORM_ID = ( -144000 ) \begintext End of IK file.