KPL/IK UVIS Instrument Kernel ============================================================================== This instrument kernel (I-kernel) contains references to the mounting alignment, internal and FOV geometry for the Cassini Ultraviolet Imaging Spectograph (UVIS) instruments. Version and Date ---------------------------------------------------------- The TEXT_KERNEL_ID stores version information of loaded project text kernels. Each entry associated with the keyword is a string that consists of four parts: the kernel name, version, entry date, and type. For example, the ISS I-kernel might have an entry as follows: TEXT_KERNEL_ID += 'CASSINI_ISS V0.0.0 29-SEPTEMBER-1999 IK' | | | | | | | | KERNEL NAME <-------+ | | | | | V VERSION <-------+ | KERNEL TYPE | V ENTRY DATE UVIS I-Kernel Version: \begindata TEXT_KERNEL_ID += 'CASSINI_UVIS V0.6.0 05-NOVEMBER-2008 IK' \begintext Version 0.6 -- November 5, 2008 -- Boris Semenov -- Added name/ID mapping, FOV, and other parameters for CASSINI_UVIS_SOL_OFF/-82849. (See [11]) -- Revised the ``Implementation Notes'' section and spell-checked comments in the whole file. Version 0.5 -- April 23, 2001 -- Scott Turner -- Updated kernel to utilize new FOV ANGLES specification. -- Updated CASSINI_UVIS_SOLAR FOV definition to the correct value. See [10] for details. Version 0.4 -- November 20, 2000 -- Scott Turner -- Added the CASSINI_UVIS_SOLAR FOV definition. -- Changed the CASSINI_UVIS_EUV_OCC and CASSINI_UVIS_FUV_OCC FOV_FRAME keywords to refer to CASSINI_UVIS_EUV and CASSINI_UVIS_FUV respectively. Version 0.3 -- October 3, 2000 -- Scott Turner -- Fixed a few minor mistakes in the text documenting boundary corner vector calculations for the UVIS_HDAC FOV. -- Added source code samples for computing FOV angular extents from the FOV definitions provided using SPICELIB and CSPICE. Version 0.2 -- August 15, 2000 -- Scott Turner -- Recalculated FOV definitions to enhance precision. Version 0.1 -- June 7, 2000 -- Scott Turner -- Changed the INS[#]_FOV_CENTER_PIXEL keyword to reflect changes in the I-kernel SIS. Version 0.0 -- March 27, 2000 -- Scott Turner -- Initial Prototype Release for Review. References ---------------------------------------------------------- 1. ``Cassini Science Instruments and Investigations'', Revised Second Printing. Stephen J. Edberg. 2. ``Kernel Pool Required Reading'' 3. JPL Cassini Project Web Page describing the instruments. 4. Cassini/NAIF SPICE Workshop, November 8-9, 1999. 5. Email from Jeff Boyer regarding necessary data for footprint calculations. 6. Cassini Spacecraft Frames Definition Kernel 7. CASPER UVIS I-kernel Version 5.0 8. CASPER HDAC I-kernel Version 2.0 9. Email from Joshua Colwell regarding CASSINI_UVIS_SOLAR FOV definition and corrections the the CASSINI_UVIS_EUV_OCC and CASSINI_UVIS_FUV_OCC FOV definitions. 10. Email from Joshua Colwell describing the official values of the CASSINI_UVIS_SOLAR FOV angular extent. 11. Email from Diane Conner, 11/04/08, providing suggested FK and IK changes per ECR-108546 ``Add UVIS_SOL_OFF vector to SPICE Frame, Instrument, and Status Kernels''. Contact Information ---------------------------------------------------------- Direct questions, comments or concerns about the contents of this kernel to: Boris Semenov, NAIF/JPL, (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 instrument kernel must ``load'' the kernel, normally during program initialization. Loading the kernel associates data items with their names in a data structure called the ``kernel pool''. The SPICE routine FURNSH loads SPICE kernels 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 ) In order for a program or subroutine to extract data from the pool, the SPICE routines GDPOOL, GIPOOL, and GCPOOL (see [2]) and GETFOV are used. This file was created and may be updated with a text editor or word processor. Naming Conventions ---------------------------------------------------------- All names referencing values in this I-kernel start with the characters `INS' followed by the NAIF Cassini spacecraft ID number (-82) followed by a NAIF three digit code for the UVIS detectors. (FUV_HI = 840, FUV_LO = 841, EUV_HI = 842, EUV_LO = 843, FUV_OCC = 845, EUV_OCC = 846, HSP = 844, HDAC = 847, SOLAR = 848, SOL_OFF = 849). The remainder of the name is an underscore character followed by the unique name of the data item. For example, the UVIS FUV_HI boresight direction in the UVIS FUV frame (``CASSINI_UVIS'' -- see [6] ) is specified by: INS-82840_BORESIGHT The upper bound on the length of the name of any data item 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. UVIS description ---------------------------------------------------------- From [3]: A spectrograph is an instrument that records spectral intensity information in one or more wavelengths of energy and then outputs the data in the form of a graph. (A spectrometer, in contrast, outputs spectral information as numerical data.) An imaging spectrograph converts the points on the graph to digital data that can be output in the form of a visual image, such as a "false color" picture. The Ultraviolet Imaging Spectrograph Subsystem (UVIS) is a set of detectors designed to measure ultraviolet light reflected by or emitted from atmospheres, rings, and surfaces to determine their compositions, distributions, aerosol contents, and temperatures. The UVIS will measure the fluctuations of starlight and sunlight as the sun and stars move behind the rings and the atmospheres of Titan and Saturn, and it will determine the atmospheric concentrations of hydrogen and deuterium. These data will be used for studies of the atmospheres, the magnetosphere, and the rings of the Saturnian system. The UVIS has two channels: the extreme ultraviolet channel and the far ultraviolet channel. The ultraviolet channels are built into weight-relieved aluminum cases, and each contains a reflecting telescope, a concave grating spectrometer, and an imaging, pulse-counting detector. The UVIS also includes a high-speed photometer channel, a hydrogen-deuterium absorption cell channel, and an electronics and control subassembly. For information on the UVIS components, see below. (UVIS) The extreme ultraviolet channel (EUV) will be used for imaging spectroscopy and spectroscopic measurements of the structure and composition of the atmospheres of Titan and Saturn. The EUV consists of a telescope with a three-position slit changer, a baffle system, and a spectrograph with a CODACON microchannel plate detector and associated electronics. The telescope consists of an off-axis parabolic section with a focal length of 100 mm, a 22 mm by 30 mm aperture, and a baffle with a field of view of 3.67 degrees by 0.34 degrees. A precision mechanism positions one of the three entrance slits at the focal plane of the telescope, each translating to a different spectral resolution. The spectrograph uses an aberration-corrected toroidal grating that focuses the spectrum onto an imaging microchannel plate detector to achieve both high sensitivity and spatial resolution along the entrance slit. The microchannel plate detector electronics consists of a low-voltage power supply, a programmable high-voltage power supply, charge-sensitive amplifiers, and associated logic. The EUV channel also contains a solar occultation mechanism to allow solar flux to enter the telescope when the sun is still 20 degrees off-axis from the primary telescope. The far ultraviolet channel (FUV) will be used for imaging spectroscopy and spectroscopic measurements of the structure and composition of the atmospheres of Titan and Saturn and of the rings. The FUV is similar to the EUV channel except for the grating ruling density, optical coatings, and detector details. The FUV electronics are similar to those for the EUV except for the addition of a high-voltage power supply for the ion pump. The high-speed photometer channel (HSP) will perform stellar occultation measurements of the structure and density of material in the rings. The HSP resides in its own module and measures undispersed (zero-order) light from its own parabolic mirror with a photomultiplier tube detector. The electronics consists of a pulse-amplifier-discriminator and a fixed-level high-voltage power supply. The hydrogen-deuterium absorption cell channel (HDAC) will be used to measure hydrogen and deuterium in the Saturn system using a hydrogen cell, an oxygen cell, a deuterium cell, and a channel electron multiplier (CEM) detector to record photons not absorbed in the cells. The hydrogen and deuterium cells are resonance absorption cells filled with pure molecular hydrogen and deuterium, respectively. They are located between an objective lens and a detector. Both cells are made of stainless steel coated with teflon and are sealed at each end with MgF2 windows. The electronics consists of a pulse-amplifier-discriminator, a fixed-level high-voltage power supply, and two filament current controllers. The UVIS microprocessor electronics and control subassembly consists of input-output elements, power conditioning, science data and housekeeping data collection electronics, and microprocessor control elements. UVIS Field of View Parameters ---------------------------------------------------------- The field of view parameters for the three focal planes that constitute the UVIS detectors are: -- Far Ultraviolet Spectrograph High (FUV_HI) -- Far Ultraviolet Spectrograph Low (FUV_LO) -- Far Ultraviolet Spectrograph Occultation Port (FUV_OCC) -- Extreme Ultraviolet Spectrograph High (EUV_HI) -- Extreme Ultraviolet Spectrograph Low (EUV_LO) -- Extreme Ultraviolet Spectrograph Occultation Port (EUV_OCC) -- Solar Occultation Port (SOLAR/SOL_OFF) -- High Speed Photometer (HSP) -- Hydrogen - Deuterium Absorption Cell (HDAC) From [7], [8], and [9] we have: Rectangular FOVs: ------------ -------------------- -------------------- Detector Horizontal Vertical ------------ -------------------- -------------------- FUV_HI 0.04297 degrees 3.6669 degrees FUV_LO 0.08594 degrees 3.6669 degrees FUV_OCC 0.48536 degrees 3.6669 degrees EUV_HI 0.05729 degrees 3.6669 degrees EUV_LO 0.11459 degrees 3.6669 degrees EUV_OCC 0.48536 degrees 3.6669 degrees SOLAR/SOL_OFF 0.45836 degrees 0.45836 degrees HSP 0.34377 degrees 0.3666 degrees ------------ -------------------- -------------------- Circular FOVs: ------------ ------------------- Detector Diameter ------------ ------------------- HDAC 3.2 degrees ------------ ------------------- The keywords INS[ID]_FOV_FRAME, INS[ID]_FOV_SHAPE, INS[ID]_BORESIGHT, and FOV ANGLE specification keywords defined below are used to describe the instrument field of view. Since the HDAC has a circular field of view and the others are rectangular, the INS[ID]_FOV_SHAPE will either be 'CIRCLE' or 'RECTANGLE'. In the case of the HDAC, GETFOV returns a single boundary vector that lies along the edge of the circular cone, and for the others four vectors. All FOV boresights lie along the Z-axis in their respective frames. Far Ultraviolet Spectrograph High (FUV_HI) FOV Definition Since FUV_HI is a rectangular field of view, four boundary corner vectors require visualization. This means two separate calculations. First consider looking down the X-axis at the X=0 plane which permits the computation of the Y components of the boundary corner vectors. In this plane the half angle of note is 1.83346495 degrees. (Note we are arbitrarily choosing a vector that terminates in the Z=1 plane.) ^ Y | ins | | /| | / | | / | | / o | |/ 1.833 | x---------------> X \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane X = 0 Now from here we see that the Y component of one boundary corner vector is: Y Component = +/- 1.0 * tan ( 1.83346495 degrees ) = +/- 0.03201093 Since the field of view is rectangular a similar computation yields the X components. This time look up the Y-axis at the Y=0 plane. The half angle of interest is 0.02148592 degrees. ^ X | ins | | /| | / | | / | | / o | |/ 0.021 | o---------------> Y \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane Y = 0 X Component = +/- 1.0 * tan ( 0.02148592 degrees ) = +/- 3.75000064D-4 This results in the following FOV definition: Far Ultraviolet Spectrograph High (FUV_HI): \begindata INS-82840_FOV_FRAME = 'CASSINI_UVIS_FUV' INS-82840_FOV_SHAPE = 'RECTANGLE' INS-82840_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82840_FOV_CLASS_SPEC = 'ANGLES' INS-82840_FOV_REF_VECTOR = ( 0.0000000000000000 +1.0000000000000000 0.0000000000000000 ) INS-82840_FOV_REF_ANGLE = ( 1.83346495 ) INS-82840_FOV_CROSS_ANGLE = ( 0.02148592 ) INS-82840_FOV_ANGLE_UNITS = 'DEGREES' \begintext Far Ultraviolet Spectrograph Low (FUV_LO) FOV Definition FUV_LO is also a rectangular field of view. Four boundary corner vectors require visualization. First consider looking down the X-axis at the X=0 plane which permits the computation of the Y components of the boundary corner vectors. In this plane the half angle of note is 1.83346495 degrees. (Note we are arbitrarily choosing a vector that terminates in the Z=1 plane.) ^ Y | ins | | /| | / | | / | | / o | |/ 1.833 | x---------------> X \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane X = 0 Now from here we see that the Y component of one boundary corner vector is: Y Component = +/- 1.0 * tan ( 1.83346495 degrees ) = +/- 0.03201093 Since the field of view is rectangular a similar computation yields the X components. This time look up the Y-axis at the Y=0 plane. The half angle of interest is 0.0429718347 degrees. ^ X | ins | | /| | / | | / | | / o | |/ 0.043 | o---------------> Y \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane Y = 0 X Component = +/- 1.0 * tan ( 0.0429718347 degrees ) = +/- 7.50000142D-4 Utilizing the ANGLES FOV specification: Far Ultraviolet Spectrograph Low (FUV_LO): \begindata INS-82841_FOV_FRAME = 'CASSINI_UVIS_FUV' INS-82841_FOV_SHAPE = 'RECTANGLE' INS-82841_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82841_FOV_CLASS_SPEC = 'ANGLES' INS-82841_FOV_REF_VECTOR = ( 0.0000000000000000 +1.0000000000000000 0.0000000000000000 ) INS-82841_FOV_REF_ANGLE = ( 1.83346495 ) INS-82841_FOV_CROSS_ANGLE = ( 0.0429718347 ) INS-82841_FOV_ANGLE_UNITS = 'DEGREES' \begintext Far Ultraviolet Spectrograph Occultation Port (FUV_OCC) FOV Definition FUV_OCC is also a rectangular field of view. Four boundary corner vectors need visualization. First consider looking down the X-axis at the X=0 plane which permits the computation of the Y components of the boundary corner vectors. In this plane the half angle of note is 1.83346495 degrees. (Note we are arbitrarily choosing a vector that terminates in the Z=1 plane.) ^ Y | ins | | /| | / | | / | | / o | |/ 1.833 | x---------------> X \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane X = 0 Now from here we see that the Y component of one boundary corner vector is: Y Component = +/- 1.0 * tan ( 1.83346495 degrees ) = +/- 0.03201093 Since the field of view is rectangular a similar computation yields the X components. This time look up the Y-axis at the Y=0 plane. The half angle of interest is 0.229183 degrees. ^ X | ins | | /| | / | | / | | / o | |/ 0.229 | o---------------> Y \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane Y = 0 X Component = +/- 1.0 * tan ( 0.229183 degrees ) = +/- 0.0040000193 This results in the following FOV definition: Far Ultraviolet Spectrograph Occultation Port (FUV_OCC): \begindata INS-82842_FOV_FRAME = 'CASSINI_UVIS_FUV' INS-82842_FOV_SHAPE = 'RECTANGLE' INS-82842_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82842_FOV_CLASS_SPEC = 'ANGLES' INS-82842_FOV_REF_VECTOR = ( 0.0000000000000000 +1.0000000000000000 0.0000000000000000 ) INS-82842_FOV_REF_ANGLE = ( 1.83346495 ) INS-82842_FOV_CROSS_ANGLE = ( 0.229183 ) INS-82842_FOV_ANGLE_UNITS = 'DEGREES' \begintext Extreme Ultraviolet Spectrograph High (EUV_HI) FOV Definition EUV_HI is also a rectangular field of view. Four boundary corner vectors require visualization. First consider looking down the X-axis at the X=0 plane which permits the computation of the Y components of the boundary corner vectors. In this plane the half angle of note is 1.83346495 degrees. (Note we are arbitrarily choosing a vector that terminates in the Z=1 plane.) ^ Y | ins | | /| | / | | / | | / o | |/ 1.833 | x---------------> X \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane X = 0 Now from here we see that the Y component of one boundary corner vector is: Y Component = +/- 1.0 * tan ( 1.83346495 degrees ) = +/- 0.03201093 Since the field of view is rectangular a similar computation yields the X components. This time look up the Y-axis at the Y=0 plane. The half angle of interest is 0.02864789 degrees. ^ X | ins | | /| | / | | / | | / o | |/ 0.029 | o---------------> Y \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane Y = 0 X Component = +/- 1.0 * tan ( 0.02864789 degrees ) = +/- 5.00000045D-4 And we end up with the following FOV definition: Extreme Ultraviolet Spectrograph High (EUV_HI): \begindata INS-82843_FOV_FRAME = 'CASSINI_UVIS_EUV' INS-82843_FOV_SHAPE = 'RECTANGLE' INS-82843_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82843_FOV_CLASS_SPEC = 'ANGLES' INS-82843_FOV_REF_VECTOR = ( 0.0000000000000000 +1.0000000000000000 0.0000000000000000 ) INS-82843_FOV_REF_ANGLE = ( 1.83346495 ) INS-82843_FOV_CROSS_ANGLE = ( 0.02864789 ) INS-82843_FOV_ANGLE_UNITS = 'DEGREES' \begintext Extreme Ultraviolet Spectrograph Low (EUV_LO) FOV Definition EUV_LO is also a rectangular field of view. Four boundary corner vectors require visualization. First consider looking down the X-axis at the X=0 plane which permits the computation of the Y components of the boundary corner vectors. In this plane the half angle of note is 1.83346495 degrees. (Note we are arbitrarily choosing a vector that terminates in the Z=1 plane.) ^ Y | ins | | /| | / | | / | | / o | |/ 1.833 | x---------------> X \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane X = 0 Now from here we see that the Y component of one boundary corner vector is: Y Component = +/- 1.0 * tan ( 1.83346495 degrees ) = +/- 0.03201093 Since the field of view is rectangular a similar computation yields the X components. This time look up the Y-axis at the Y=0 plane. The half angle of interest is 0.05729578 degrees. ^ X | ins | | /| | / | | / | | / o | |/ 0.057 | o---------------> Y \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane Y = 0 X Component = +/- 1.0 * tan ( 0.05729578 degrees ) = +/- 0.00100000034 Utilizing the ANGLES FOV specification: Extreme Ultraviolet Spectrograph Low (EUV_LO): \begindata INS-82844_FOV_FRAME = 'CASSINI_UVIS_EUV' INS-82844_FOV_SHAPE = 'RECTANGLE' INS-82844_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82844_FOV_CLASS_SPEC = 'ANGLES' INS-82844_FOV_REF_VECTOR = ( 0.0000000000000000 +1.0000000000000000 0.0000000000000000 ) INS-82844_FOV_REF_ANGLE = ( 1.83346495 ) INS-82844_FOV_CROSS_ANGLE = ( 0.05729578 ) INS-82844_FOV_ANGLE_UNITS = 'DEGREES' \begintext Extreme Ultraviolet Spectrograph Occultation Port (EUV_OCC) FOV Definition EUV_OCC is also a rectangular field of view. Four boundary corner vectors require visualization. First consider looking down the X-axis at the X=0 plane which permits the computation of the Y components of the boundary corner vectors. In this plane the half angle of note is 1.83346495 degrees. (Note we are arbitrarily choosing a vector that terminates in the Z=1 plane.) ^ Y | ins | | /| | / | | / | | / o | |/ 1.833 | x---------------> X \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane X = 0 Now from here we see that the Y component of one boundary corner vector is: Y Component = +/- 1.0 * tan ( 1.83346495 degrees ) = +/- 0.03201093 Since the field of view is rectangular a similar computation yields the X components. This time look up the Y-axis at the Y=0 plane. The half angle of interest is 0.229183 degrees. ^ X | ins | | /| | / | | / | | / o | |/ 0.229 | o---------------> Y \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane Y = 0 X Component = +/- 1.0 * tan ( 0.229183 degrees ) = +/- 0.0040000193 This results in the following definition: Extreme Ultraviolet Spectrograph Occultation Port (EUV_OCC): \begindata INS-82845_FOV_FRAME = 'CASSINI_UVIS_EUV' INS-82845_FOV_SHAPE = 'RECTANGLE' INS-82845_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82845_FOV_CLASS_SPEC = 'ANGLES' INS-82845_FOV_REF_VECTOR = ( 0.0000000000000000 +1.0000000000000000 0.0000000000000000 ) INS-82845_FOV_REF_ANGLE = ( 1.83346495 ) INS-82845_FOV_CROSS_ANGLE = ( 0.229183 ) INS-82845_FOV_ANGLE_UNITS = 'DEGREES' \begintext Solar Occultation Port (SOLAR and SOL_OFF) FOV Definitions SOLAR is a square field of view. Four boundary corner vectors require visualization. First consider looking down the X-axis at the X=0 plane which permits the computation of the Y components of the boundary corner vectors. In this plane the half angle of note is 0.229183118 degrees. (Note we are arbitrarily choosing a vector that terminates in the Z=1 plane.) ^ Y | ins | | /| | / | | / | | / o | |/ 0.229 | x---------------> X \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane X = 0 Now from here we see that the Y component of one boundary corner vector is: Y Component = +/- 1.0 * tan ( 0.229183118 degrees ) = +/- 0.004000021 Since the field of view is square the same computation holds for the X components. This results in the following FOV definition given below. (Note - we are using radians to prescribe the angular extents.) Solar Occultation Port (SOLAR) FOV is defined relative to the CASSINI_UVIS_SOLAR frame incorporating the nominal alignment: \begindata INS-82848_FOV_FRAME = 'CASSINI_UVIS_SOLAR' INS-82848_FOV_SHAPE = 'RECTANGLE' INS-82848_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82848_FOV_CLASS_SPEC = 'ANGLES' INS-82848_FOV_REF_VECTOR = ( 0.0000000000000000 +1.0000000000000000 0.0000000000000000 ) INS-82848_FOV_REF_ANGLE = ( 0.004 ) INS-82848_FOV_CROSS_ANGLE = ( 0.004 ) INS-82848_FOV_ANGLE_UNITS = 'RADIANS' \begintext Solar Occultation Port with Offset (SOL_OFF) has the same FOV as SOLAR except that it is defined relative to the CASSINI_UVIS_SOL_OFF frame incorporating the actual alignment: \begindata INS-82849_FOV_FRAME = 'CASSINI_UVIS_SOL_OFF' INS-82849_FOV_SHAPE = 'RECTANGLE' INS-82849_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82849_FOV_CLASS_SPEC = 'ANGLES' INS-82849_FOV_REF_VECTOR = ( 0.0000000000000000 +1.0000000000000000 0.0000000000000000 ) INS-82849_FOV_REF_ANGLE = ( 0.004 ) INS-82849_FOV_CROSS_ANGLE = ( 0.004 ) INS-82849_FOV_ANGLE_UNITS = 'RADIANS' \begintext High Speed Photometer (HSP) FOV Definition HSP is also a rectangular field of view. Four boundary corner vectors require visualization. First consider looking down the X-axis at the X=0 plane which permits the computation of the Y components of the boundary corner vectors. In this plane the half angle of note is 0.1833465 degrees. (Note we are arbitrarily choosing a vector that terminates in the Z=1 plane.) ^ Y | ins | | /| | / | | / | | / o | |/ 0.183 | x---------------> X \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane X = 0 Now from here we see that the Y component of one boundary corner vector is: Y Component = +/- 1.0 * tan ( 0.1833465 degrees ) = +/- 0.0032000110 Since the field of view is rectangular a similar computation yields the X components. This time look up the Y-axis at the Y=0 plane. The half angle of interest is 0.1718873385 degrees. ^ X | ins | | /| | / | | / | | / o | |/ 0.172 | o---------------> Y \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane Y = 0 X Component = +/- 1.0 * tan ( 0.1718873385 degrees ) = +/- 0.0030000089 This results in the following FOV definition: High Speed Photometer (HSP): \begindata INS-82846_FOV_FRAME = 'CASSINI_UVIS_HSP' INS-82846_FOV_SHAPE = 'RECTANGLE' INS-82846_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82846_FOV_CLASS_SPEC = 'ANGLES' INS-82846_FOV_REF_VECTOR = ( 0.0000000000000000 +1.0000000000000000 0.0000000000000000 ) INS-82846_FOV_REF_ANGLE = ( 0.1833465 ) INS-82846_FOV_CROSS_ANGLE = ( 0.1718873385 ) INS-82846_FOV_ANGLE_UNITS = 'DEGREES' \begintext Hydrogen - Deuterium Absorption Cell (HDAC) FOV Definition HDAC's FOV is circular; it's diameter is 3.2 degrees, looking up the Y-axis in the CASSINI_UVIS_HDAC frame we have: (Note we are arbitrarily choosing a vector that terminates in the Z=1 plane.) ^ X | ins | | /| | / | | / | | / o | |/ 1.6 | o---------------> Y \ | Z ins \ | ins \ | \ | \| |-- 1.0 --| Plane Y = 0 Now from here we see that the X component of one 'boundary corner' vector is: X Component = 1.0 * tan ( 1.6 degrees ) = 0.027932529197 This yields the following FOV definition: Hydrogen - Deuterium Absorption Cell (HDAC): \begindata INS-82847_FOV_FRAME = 'CASSINI_UVIS_HDAC' INS-82847_FOV_SHAPE = 'CIRCLE' INS-82847_BORESIGHT = ( 0.0000000000000000 0.0000000000000000 +1.0000000000000000 ) INS-82847_FOV_CLASS_SPEC = 'ANGLES' INS-82847_FOV_REF_VECTOR = ( +1.0000000000000000 0.0000000000000000 0.0000000000000000 ) INS-82847_FOV_REF_ANGLE = ( 1.6 ) INS-82847_FOV_ANGLE_UNITS = 'DEGREES' \begintext UVIS Pixel Parameters ---------------------------------------------------------- These parameters describe the pixel structure associated with the instruments and their fields of views. In some cases this is a generalization of the notion of pixel, in that instead of representing pixels on a CCD they may represent a collection of individual detectors. Far Ultraviolet Spectrograph High (FUV_HI) \begindata INS-82840_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82840_PIXEL_SAMPLES = ( 1 ) INS-82840_PIXEL_LINES = ( 1 ) \begintext Far Ultraviolet Spectrograph Low (FUV_LO) \begindata INS-82841_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82841_PIXEL_SAMPLES = ( 1 ) INS-82841_PIXEL_LINES = ( 1 ) \begintext Far Ultraviolet Spectrograph Occultation Port (FUV_OCC) \begindata INS-82842_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82842_PIXEL_SAMPLES = ( 1 ) INS-82842_PIXEL_LINES = ( 1 ) \begintext Extreme Ultraviolet Spectrograph High (EUV_HI) \begindata INS-82843_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82843_PIXEL_SAMPLES = ( 1 ) INS-82843_PIXEL_LINES = ( 1 ) \begintext Extreme Ultraviolet Spectrograph Low (EUV_LO) \begindata INS-82844_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82844_PIXEL_SAMPLES = ( 1 ) INS-82844_PIXEL_LINES = ( 1 ) \begintext Extreme Ultraviolet Spectrograph Occultation Port (EUV_OCC) \begindata INS-82845_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82845_PIXEL_SAMPLES = ( 1 ) INS-82845_PIXEL_LINES = ( 1 ) \begintext Solar Occultation Port (SOLAR and SOL_OFF) \begindata INS-82848_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82848_PIXEL_SAMPLES = ( 1 ) INS-82848_PIXEL_LINES = ( 1 ) INS-82849_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82849_PIXEL_SAMPLES = ( 1 ) INS-82849_PIXEL_LINES = ( 1 ) \begintext High Speed Photometer (HSP) \begindata INS-82846_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82846_PIXEL_SAMPLES = ( 1 ) INS-82846_PIXEL_LINES = ( 1 ) \begintext Hydrogen - Deuterium Absorption Cell (HDAC) \begindata INS-82847_FOV_CENTER_PIXEL = ( 0, 0 ) INS-82847_PIXEL_SAMPLES = ( 1 ) INS-82847_PIXEL_LINES = ( 1 ) \begintext Instrument Mode Timing ---------------------------------------------------------- The following values were provided as samples in [5]. The values are defined in [5] as follows: ``The initial values for the following keywords are given per instrument number: INS[instrument number]_[instrument acronym]_MODE_NAME INS[instrument number]_[instrument acronym]_TRIGGER_OFFSET INS[instrument number]_[instrument acronym]_CYCLE_DURATION INS..._MODE_NAME contains the name of the instrument mode for the INS..._TRIGGER_OFFSET and INS..._CYCLE_DURATION keywords. INS..._TRIGGER_OFFSET specifies the reference time of the first instrument frame (to be calculated for a footprint) relative to the time of transacting the corresponding TRIGGER command. The units are SFOC duration. INS..._CYCLE_DURATION specifies the duration between successive instrument frames (from the first one) for the INS..._MODE_NAME.'' FUV_HI Mode Timing The following values define the instrument modes and timing for UVIS FUV_HI. \begindata INS-82840_MODE_NAME = 'NOMINAL' INS-82840_TRIGGER_OFFSET = '0:01:00.0' INS-82840_CYCLE_DURATION = '0:01:00.0' \begintext FUV_LO Mode Timing The following values define the instrument modes and timing for UVIS FUV_LO. \begindata INS-82841_MODE_NAME = 'NOMINAL' INS-82841_TRIGGER_OFFSET = '0:01:00.0' INS-82841_CYCLE_DURATION = '0:01:00.0' \begintext FUV_OCC Mode Timing The following values define the instrument modes and timing for the UVIS FUV_OCC. \begindata INS-82842_MODE_NAME = 'NOMINAL' INS-82842_TRIGGER_OFFSET = '0:01:00.0' INS-82842_CYCLE_DURATION = '0:01:00.0' \begintext EUV_HI Mode Timing The following values define the instrument modes and timing for UVIS EUV_HI. \begindata INS-82843_MODE_NAME = 'NOMINAL' INS-82843_TRIGGER_OFFSET = '0:01:00.0' INS-82843_CYCLE_DURATION = '0:01:00.0' \begintext EUV_LO Mode Timing The following values define the instrument modes and timing for UVIS EUV_LO. \begindata INS-82844_MODE_NAME = 'NOMINAL' INS-82844_TRIGGER_OFFSET = '0:01:00.0' INS-82844_CYCLE_DURATION = '0:01:00.0' \begintext EUV_OCC Mode Timing The following values define the instrument modes and timing for the UVIS EUV_OCC. \begindata INS-82845_MODE_NAME = 'NOMINAL' INS-82845_TRIGGER_OFFSET = '0:01:00.0' INS-82845_CYCLE_DURATION = '0:01:00.0' \begintext SOLAR Mode Timing The following values define the instrument modes and timing for the UVIS SOLAR. \begindata INS-82848_MODE_NAME = 'NOMINAL' INS-82848_TRIGGER_OFFSET = '0:01:00.0' INS-82848_CYCLE_DURATION = '0:01:00.0' INS-82849_MODE_NAME = 'NOMINAL' INS-82849_TRIGGER_OFFSET = '0:01:00.0' INS-82849_CYCLE_DURATION = '0:01:00.0' \begintext HSP Mode Timing The following values define the instrument modes and timing for the UVIS HSP. \begindata INS-82846_MODE_NAME = 'NOMINAL' INS-82846_TRIGGER_OFFSET = '0:01:00.0' INS-82846_CYCLE_DURATION = '0:01:00.0' \begintext HDAC Mode Timing The following values define the instrument modes and timing for the UVIS HDAC. \begindata INS-82847_MODE_NAME = 'NOMINAL' INS-82847_TRIGGER_OFFSET = '0:01:00.0' INS-82847_CYCLE_DURATION = '0:01:00.0' \begintext NAIF ID Code to Name Mapping ---------------------------------------------------------- The following keywords define names for the corresponding ID Codes. See [4] for details. \begindata NAIF_BODY_NAME += ( 'CASSINI_UVIS_FUV_HI' ) NAIF_BODY_CODE += ( -82840 ) NAIF_BODY_NAME += ( 'CASSINI_UVIS_FUV_LO' ) NAIF_BODY_CODE += ( -82841 ) NAIF_BODY_NAME += ( 'CASSINI_UVIS_FUV_OCC' ) NAIF_BODY_CODE += ( -82842 ) NAIF_BODY_NAME += ( 'CASSINI_UVIS_EUV_HI' ) NAIF_BODY_CODE += ( -82843 ) NAIF_BODY_NAME += ( 'CASSINI_UVIS_EUV_LO' ) NAIF_BODY_CODE += ( -82844 ) NAIF_BODY_NAME += ( 'CASSINI_UVIS_EUV_OCC' ) NAIF_BODY_CODE += ( -82845 ) NAIF_BODY_NAME += ( 'CASSINI_UVIS_SOLAR' ) NAIF_BODY_CODE += ( -82848 ) NAIF_BODY_NAME += ( 'CASSINI_UVIS_SOL_OFF' ) NAIF_BODY_CODE += ( -82849 ) NAIF_BODY_NAME += ( 'CASSINI_UVIS_HSP' ) NAIF_BODY_CODE += ( -82846 ) NAIF_BODY_NAME += ( 'CASSINI_UVIS_HDAC' ) NAIF_BODY_CODE += ( -82847 ) \begintext Platform ID ---------------------------------------------------------- The UVIS instrument is mounted on the Remote Sensing Palette, which is connected to the Cassini Spacecraft body. Therefore the value in the keywords below are -82000. \begindata INS-82840_PLATFORM_ID = ( -82000 ) INS-82841_PLATFORM_ID = ( -82000 ) INS-82842_PLATFORM_ID = ( -82000 ) INS-82843_PLATFORM_ID = ( -82000 ) INS-82844_PLATFORM_ID = ( -82000 ) INS-82845_PLATFORM_ID = ( -82000 ) INS-82846_PLATFORM_ID = ( -82000 ) INS-82847_PLATFORM_ID = ( -82000 ) INS-82848_PLATFORM_ID = ( -82000 ) \begintext