KPL/IK SPICAM Instrument Kernel =========================================================================== This instrument kernel (I-kernel) contains references to mounting alignment, operating modes, and timing as well as internal and FOV geometry for the Mars Express Spectroscopy for Investigation of Characteristics of the atmosphere of Mars (SPICAM). Version and Date ----------------------------------------------------------------------------- Version 0.3 -- March 23, 2021 -- Ricardo Valles Blanco, ESAC/ESA Corrected typos and updated contact information for Mars Express PDS3 V2.0 release. Version 0.2 -- February 01, 2021 -- Alfredo Escalante Lopez, ESAC/ESA Corrected boresight vector from +Z axis to +Y axis as specified in the FK description. Version 0.1 -- March 25, 2020 -- Marc Costa Sitja, ESAC/ESA Updated BIN4 FOV definition. Removed Platform ID section. Version 0.0 -- January 16, 2019 -- Marc Costa Sitja, ESAC/ESA First draft. References ----------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading'' 2. ``Frames Required Reading'' 3. ``C-Kernel Required Reading" 4. Mars Express Spacecraft Frames Definition Kernel 5. ``Mars Express Instrument Design - SPICAM: SPECTROSCOPY FOR INVESTIGATION OF CHARACTERISTICS OF THE ATMOSPHERE OF MARS'' http://sci.esa.int/mars-express/34826-design/?fbodylongid=1602 Accessed on 28th February 2018. 6. ``SPICAM on Mars Express: Observing modes and overview of UV spectrometer data and scientific results'', Bertaux, J.-L., et al. (2006), J. Geophys. Res., 111. 7. ``SPICAM LIGHT Flight User / Operations MANUAL'', E. Dimarellis Service d'Aeronomie du CNRS, SP-DES-032, Issue 4, 17th April 2002. 7. ``MARS EXPRESS SPICAM GEOMETRY Computation'', SPICAM_GEOMETRY_DESC.TXT, version 014, September 15th, 2005. Contact Information ----------------------------------------------------------------------------- If you have any questions regarding this file contact SPICE support at ESAC: Alfredo Escalante Lopez (+34) 91-8131-429 spice@sciops.esa.int or NAIF at JPL: Boris Semenov (818) 354-8136 Boris.Semenov@jpl.nasa.gov 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. * SPICEYPY 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 MEX instrument ID code, constructed using the spacecraft ID number (-41) followed by the NAIF three digit ID number for one of the SPICAM data item. These IDs are as follows Instrument name ID -------------------- ------ MEX_SPICAM_UV_STELLAR -41611 MEX_SPICAM_UV_SOLAR -41612 MEX_SPICAM_UV_NADIR_SLIT -41613 MEX_SPICAM_UV_NADIR_BIN_2 -41614 MEX_SPICAM_UV_NADIR_BIN_4 -41615 MEX_SPICAM_UV_NADIR_BIN_8 -41616 MEX_SPICAM_UV_NADIR_BIN_16 -41617 MEX_SPICAM_UV_NADIR_BIN_32 -41618 MEX_SPICAM_IR_STELLAR -41621 MEX_SPICAM_IR_SOLAR -41622 MEX_SPICAM_IR_NADIR -41623 The remainder of the name is an underscore character followed by the unique name of the data item. For example, the SPICAM UV sensor stellar boresight direction in the MEX_SPICAM_STELLAR frame (see [2]) is specified by: INS-41610_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 [6]: SPICAM is a lightweight (4.7 kg) UV-IR dual spectrometer dedicated primarily to the study of the atmosphere of Mars. SPICAM-UV, the UV spectrometer (118 - 320 nm) for nadir and limb viewing, and determination of the atmosphere's vertical profile by solar and stellar occultations. This channel enables to quantify the presence of H2O, O3 and aerosols. It also studies the vertical profile of the atmosphere and ionosphere's temperatures. SPICAM-IR: the infrared spectrometer (1.1 - 1.7 micro) for nadir sounding and solar occultation of H2O. From [5]: Operational Modes ~~~~~~~~~~~~~~~~~ The operational modes of SPICAM are Test mode (ground use only), Star mode, Sun mode, Limb mode and Nadir mode. The operational modes are derived from the scientific objectives and the related spacecraft attitudes. In Nadir mode, the instrument will point directly at the planet and will analyse solar radiation that has travelled through the atmosphere after being reflected from the planet surface. Nadir observations allow the measurement of total column abundance of atmospheric components. In star or Sun mode, the instrument will point tangentially through the atmosphere towards a star, or the Sun, which is observed through the atmosphere as it rises or sets. The instrument then analyses the light once components of it have been absorbed by the atmosphere, allowing derivation of vertical concentration profiles for atmospheric components. In limb pointing mode, the instrument will point across the atmosphere, as during Star mode, but without a target star, and the instrument will analyse the vertical profile of aeronomic emissions. SPICAM UV channel ~~~~~~~~~~~~~~~~~ The SPICAM ultraviolet channel (SUV) is based around a holographic diffraction grating. The first optical element in the UV channel is an off-axis parabolic mirror, which collects the incident light entering through either the nadir or solar aperture and focuses it. In the focal plane of the mirror, there is a slit, which can be moved in and out of the field of view by a mechanical actuator, providing two configurations: - Slit absent, for observation of stellar occultations with a field of view of 1 x 3.16 degrees; - Slit present, for the observation of extended sources. The slit has two parts, with two different widths, to give different flux resolutions. The focal plane is the entrance of the spectrometer, a holographic concave grating, which collects the incoming light and directs it to the detector block. The detection block consists of a CCD detector equipped with an image intensifier tube. The spectrum of a single source point in the focal plane is dispersed along the lines of the CCD. The usable spectral band is 118 to 320 nm, chosen so as to offer good resolution (~1 nm) for stellar observations and to cover the CO2 and O3 bands. The lower wavelength was selected to be just below the Lyman alpha wavelength and the upper wavelength was chosen to reject visible light. The quantum efficiency of the photocathode is zero beyond 320 nm and the detector is therefore solar blind. The detector has a large dynamic range - by varying the gain of the image intensifier, the spectrometer can perform individual photon counting and deal with very high input intensities. To observe the Sun, a five-millimetre diameter mirror is positioned so as to reflect the light from the Sun via a dedicated entrance aperture onto the parabolic mirror. The following table summarizes the parameters of the UV channel: Parameter | Units | Value/Description Remarks -------------------------+--------------+---------------------------- Main Characteristics | | | | Spectral range | nm | 118 - 320 Spectral sampling | nm / pixel | 0.55 (or dispersion) | | Usable dimensions | mm | 40 x 40 of primary mirror | | Slit width | mm | 0.05 and 0.5 Slit length | mm | 6.6 Transmission of | % | 30 optics (Telescope + | | grating) | | Pointing accuracy | deg | >0.2 Detector | | Intensified charge | | coupled device (CCD) CCD dimensions | pixels | 384 x 288 CCD pixel size | micron | 23 x 23 FOV of one pixel | arcsec | 40 x 40 (iFOV) | | | | Mirror Characteristics | | | | Off-axis portion of | mm | x = 30 parent with origin | | y = 0 at centre of parent | | z = 1.875 paraboloid | | Focal length | mm | 120 Dimensions | mm | 44 x 52 Entrance pupil | mm | 40 x 40 dimensions | ms | 32 to 1000 (typical time Usable FOV | degrees | 1 x 3.16 | | Grating Characteristics | | | | Type | - | Holographic Shape | - | Toroidal Dimensions | mm | 50 x 50 Radius of curvature | mm | 148.94 Grooves per mm | - | 280 Blaze wavelength | nm | 170 Incident angle | degrees | ~6.5 | | SPICAM IR channel ~~~~~~~~~~~~~~~~~ The SPICAM infrared channel (SIR) is based around a scanning acousto-optical tunable filter (AOTF). The entrance optical system comprises a lens telescope with a diameter of thirty millimetres and a collimator lens, which collect the incoming radiation and direct it onto the AOTF. The AOTF consists of a tellurium oxide (TeO2) crystal to which an acoustic wave is applied. The acoustic wave propagating in the crystal causes it to act in a similar way to a diffraction grating. A radio-frequency synthesizer drives a piezo-electric crystal attached to the TeO2 crystal to produce the wave. The frequency of excitation determines the wavelength of the acoustic waves and hence the select wavelength of the AOTF. The frequency range of the synthesizer corresponds to an AOTF passband of 1.1 - 1.7 micron The two output beams from the AOTF are collimated by another lens and detected by two indium gallium arsenide PIN photodiodes. The following table summarizes the parameters of the IR channel: Parameter | Units | Value/Description Remarks -------------------------+--------------+---------------------------- Diameter of primary | mm | 30 lens | | FOV | degrees | 1 (3x10e-4 steradians) Slit width | mm | 1 Wavelength range | nm | 1100 - 1700 Sampling per pixel | nm | 0.45 to 1.12 Optics | % | 25 Transmissivity | | Detector | - | InGaAs PIN photodiode Resolution at nadir | km | 5 x 5 | | Mounting Alignment ----------------------------------------------------------------------------- Refer to the latest version of the Mars Express Frames Definition Kernel (FK) [4] for the SPICAM reference frame definitions and mounting alignment information. SPICAM Apparent Field-of-View Layout ----------------------------------------------------------------------------- The instrument has two openings for Nadir viewing, one for UV channel, the other for IR channel. In addition, the UV and IR channel have an opening for Solar viewing (from [7]). At the entrance of the spectrometer, we may have (or not) a slit. Along the slit, the width is not constant and we have a narrow part and a wide part of the slit. UV FOV ~~~~~~ The data obtained in all modes are 5 bands on a CCD in the row axis. The positions and the widths of the bands are somewhat flexible and are determined by the telemetry. The slit is oriented in the column axis of the CCD, parallel to the S/C +X axis. For UV, there is a full CCD field of view, and each pixel has its own elementary field of view. The full CCD is 408 x 290 pixels. The FOV is defined at focus of parabolic mirror at the slit. The slit is 50 microns wide in its narrow part and 500 microns in its large part. pixel size is 23 microns. 20 pixels (~0.2 deg, ~500 microns) |<----------->| 6.-------------.5 (10, 144) --- | | ^ Wide Slit | | | | | 288 rows | | | | 7'-----+ +-----'4 --- | 8| |3 ^ | ---->| |<---- 2 pixels | | | | (~0.02 deg, | | | | ~50 microns) | | Narrow Slit | | | | | | 200 rows | | (0,0)|+| --- | | | | ^ | | +Zsc | | | | | <--------x | | | | | +Ysc | | | | | | | | | | 144 rows | | | | | | | | V | | | | | +Xsc | | | | | | | | | | | | | | | |_| _v_ _v_ _v_ (-1, -144) 1 2 IR FOV ~~~~~~ For IR, there are only 2 pixels, one for each polarization. The field of view of each pixel is supposed to be the same. IR pixel field of view is 1 deg, much larger than the UV pixel FOV. FOV Definitions --------------------------------------------------------------------------- This section contains assignments defining the SPICAM Units FOVs. These definitions are based on the spectrometer parameters provided in the previous sections and are provided in a format consistent with/required by the SPICE TOOLKIT function GETFOV. The following FOV definitions correspond to the NAIF Body Names: MEX_SPICAM_UV1_STAR, MEX_SPICAM_UV2_SUN, MEX_SPICAM_UV1_NADIR_SLIT, MEX_SPICAM_UV1_NADIR_BIN_2, MEX_SPICAM_UV1_NADIR_BIN_4, MEX_SPICAM_UV1_NADIR_BIN_8, MEX_SPICAM_UV1_NADIR_BIN_16 and MEX_SPICAM_UV1_NADIR_BIN_32. \begindata INS-41611_NAME = 'MEX_SPICAM_UV1_STAR' INS-41611_BORESIGHT = ( 0.000, 1.000, 0.000 ) INS-41611_FOV_FRAME = 'MEX_SPICAM_STELLAR' INS-41611_FOV_SHAPE = 'RECTANGLE' INS-41611_FOV_CLASS_SPEC = 'ANGLES' INS-41611_FOV_REF_VECTOR = ( 0.000, 0.000, 1.000 ) INS-41611_FOV_REF_ANGLE = ( 0.00549 ) INS-41611_FOV_CROSS_VECTOR = ( 1.000, 0.000, 0.000 ) INS-41611_FOV_CROSS_ANGLE = ( 0.00549 ) INS-41611_FOV_ANGLE_UNITS = 'DEGREES' INS-41612_NAME = 'MEX_SPICAM_UV2_SUN' INS-41612_BORESIGHT = ( 1.000, 0.000, 0.000 ) INS-41612_FOV_FRAME = 'MEX_SPICAM_SOLAR' INS-41612_FOV_SHAPE = 'RECTANGLE' INS-41612_FOV_CLASS_SPEC = 'ANGLES' INS-41612_FOV_REF_VECTOR = ( 0.000, 1.000, 0.000 ) INS-41612_FOV_REF_ANGLE = ( 0.01098 ) INS-41612_FOV_CROSS_VECTOR = ( 0.000, 0.000, 1.000 ) INS-41612_FOV_CROSS_ANGLE = ( 0.0549 ) INS-41612_FOV_ANGLE_UNITS = 'DEGREES' INS-41613_NAME = 'MEX_SPICAM_UV1_NADIR_SLIT' INS-41613_BORESIGHT = ( 0.0 1.0 0.0 ) INS-41613_FOV_FRAME = 'MEX_SPICAM_NADIR' INS-41613_FOV_SHAPE = 'POLYGON' INS-41613_FOV_BOUNDARY_CORNERS = ( 0.00019163715421492266 1.0 0.027602756958489967 -0.00019163715421492266 1.0 0.027602756958489967 -0.00019163715421492266 1.0 -0.010732092509160143 -0.00191637386463844900 1.0 -0.010732092509160143 -0.00191637386463844900 1.0 -0.027602756958489967 0.00191637386463844900 1.0 -0.027602756958489967 0.00191637386463844900 1.0 -0.010732092509160143 0.00019163715421492266 1.0 -0.010732092509160143 ) INS-41614_NAME = 'MEX_SPICAM_UV1_NADIR_BIN_2' INS-41614_BORESIGHT = ( 0.000, 1.000, 0.000 ) INS-41614_FOV_FRAME = 'MEX_SPICAM_NADIR' INS-41614_FOV_SHAPE = 'RECTANGLE' INS-41614_FOV_CLASS_SPEC = 'ANGLES' INS-41614_FOV_REF_VECTOR = ( 1.000, 0.000, 0.000 ) INS-41614_FOV_REF_ANGLE = ( 0.01098 ) INS-41614_FOV_CROSS_VECTOR = ( 0.000, 0.000, 1.000 ) INS-41614_FOV_CROSS_ANGLE = ( 0.0549 ) INS-41614_FOV_ANGLE_UNITS = 'DEGREES' INS-41615_NAME = 'MEX_SPICAM_UV1_NADIR_BIN_4' INS-41615_BORESIGHT = ( 0.000, 1.000, 0.000 ) INS-41615_FOV_FRAME = 'MEX_SPICAM_NADIR' INS-41615_FOV_SHAPE = 'RECTANGLE' INS-41615_FOV_CLASS_SPEC = 'ANGLES' INS-41615_FOV_REF_VECTOR = ( 1.000, 0.000, 0.000 ) INS-41615_FOV_REF_ANGLE = ( 0.01098 ) INS-41615_FOV_CROSS_VECTOR = ( 0.000, 0.000, 1.000 ) INS-41615_FOV_CROSS_ANGLE = ( 0.1098 ) INS-41615_FOV_ANGLE_UNITS = 'DEGREES' INS-41616_NAME = 'MEX_SPICAM_UV1_NADIR_BIN_8' INS-41616_BORESIGHT = ( 0.000, 1.000, 0.000 ) INS-41616_FOV_FRAME = 'MEX_SPICAM_NADIR' INS-41616_FOV_SHAPE = 'RECTANGLE' INS-41616_FOV_CLASS_SPEC = 'ANGLES' INS-41616_FOV_REF_VECTOR = ( 1.000, 0.000, 0.000 ) INS-41616_FOV_REF_ANGLE = ( 0.01098 ) INS-41616_FOV_CROSS_VECTOR = ( 0.000, 0.000, 1.000 ) INS-41616_FOV_CROSS_ANGLE = ( 0.2196 ) INS-41616_FOV_ANGLE_UNITS = 'DEGREES' INS-41617_NAME = 'MEX_SPICAM_UV1_NADIR_BIN_16' INS-41617_BORESIGHT = ( 0.000, 1.000, 0.000 ) INS-41617_FOV_FRAME = 'MEX_SPICAM_NADIR' INS-41617_FOV_SHAPE = 'RECTANGLE' INS-41617_FOV_CLASS_SPEC = 'ANGLES' INS-41617_FOV_REF_VECTOR = ( 1.000, 0.000, 0.000 ) INS-41617_FOV_REF_ANGLE = ( 0.01098 ) INS-41617_FOV_CROSS_VECTOR = ( 0.000, 0.000, 1.000 ) INS-41617_FOV_CROSS_ANGLE = ( 0.4392 ) INS-41617_FOV_ANGLE_UNITS = 'DEGREES' INS-41618_NAME = 'MEX_SPICAM_UV1_NADIR_BIN_32' INS-41618_BORESIGHT = ( 0.000, 1.000, 0.000 ) INS-41618_FOV_FRAME = 'MEX_SPICAM_NADIR' INS-41618_FOV_SHAPE = 'RECTANGLE' INS-41618_FOV_CLASS_SPEC = 'ANGLES' INS-41618_FOV_REF_VECTOR = ( 1.000, 0.000, 0.000 ) INS-41618_FOV_REF_ANGLE = ( 0.01098 ) INS-41618_FOV_CROSS_VECTOR = ( 0.000, 0.000, 1.000 ) INS-41618_FOV_CROSS_ANGLE = ( 0.8784 ) INS-41618_FOV_ANGLE_UNITS = 'DEGREES' INS-41619_NAME = 'MEX_SPICAM_UV1_CCD' INS-41619_BORESIGHT = ( 0.000, 1.000, 0.000 ) INS-41619_FOV_FRAME = 'MEX_SPICAM_NADIR' INS-41619_FOV_SHAPE = 'RECTANGLE' INS-41619_FOV_CLASS_SPEC = 'ANGLES' INS-41619_FOV_REF_VECTOR = ( 0.000, 0.000, 1.000 ) INS-41619_FOV_REF_ANGLE = ( 1.600128 ) INS-41619_FOV_CROSS_VECTOR = ( 1.000, 0.000, 0.000 ) INS-41619_FOV_CROSS_ANGLE = ( 2.133504 ) INS-41619_FOV_ANGLE_UNITS = 'DEGREES' \begintext Please note that the FOV reference and cross angles are defined with half angle values. The following FOV definitions correspond to the NAIF Body Names: MEX_SPICAM_IR1_STELLAR, MEX_SPICAM_IR1_NADIR and MEX_SPICAM_IR2_SOLAR. \begindata INS-41621_NAME = 'MEX_SPICAM_IR1_STAR' INS-41621_BORESIGHT = ( 0.000, 1.000, 0.000 ) INS-41621_FOV_FRAME = 'MEX_SPICAM_STELLAR' INS-41621_FOV_SHAPE = 'CIRCLE' INS-41621_FOV_CLASS_SPEC = 'ANGLES' INS-41621_FOV_REF_VECTOR = ( 1.000, 0.000, 0.000 ) INS-41621_FOV_REF_ANGLE = ( 0.5 ) INS-41621_FOV_ANGLE_UNITS = 'DEGREES' INS-41622_NAME = 'MEX_SPICAM_IR2_SUN' INS-41622_BORESIGHT = ( 1.000, 0.000, 0.000 ) INS-41622_FOV_FRAME = 'MEX_SPICAM_SOLAR' INS-41622_FOV_SHAPE = 'CIRCLE' INS-41622_FOV_CLASS_SPEC = 'ANGLES' INS-41622_FOV_REF_VECTOR = ( 0.000, 1.000, 0.000 ) INS-41622_FOV_REF_ANGLE = ( 0.5 ) INS-41622_FOV_ANGLE_UNITS = 'DEGREES' INS-41623_NAME = 'MEX_SPICAM_IR1_NADIR' INS-41623_BORESIGHT = ( 0.000, 1.000, 0.000 ) INS-41623_FOV_FRAME = 'MEX_SPICAM_NADIR' INS-41623_FOV_SHAPE = 'CIRCLE' INS-41623_FOV_CLASS_SPEC = 'ANGLES' INS-41623_FOV_REF_VECTOR = ( 1.000, 0.000, 0.000 ) INS-41623_FOV_REF_ANGLE = ( 0.5 ) INS-41623_FOV_ANGLE_UNITS = 'DEGREES' \begintext End of IK file.