KPL/IK ASPERA Instrument kernel =========================================================================== This instrument kernel (I-kernel) contains Mars Express ASPERA detector geometry parameters. Version and Date --------------------------------------------------------------------------- Version 0.1 -- July 18, 2003 -- Boris Semenov, NAIF/JPL Corrected spelling and grammar. Version 0.0 -- May 19, 2003 -- Boris Semenov, NAIF/JPL Initial release. References --------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading'' 2. ``C-kernel Required Reading'' 3. ``ASPERA-3'' ME-ASP-DS-0002, Draft Rev. 1, 23 April, 1999 4. Mars Express Frames Definition Kernel (FK), latest version. Implementation Notes -------------------------------------------------------- Applications that need SPICE I-kernel data must ``load'' the I-kernel file, normally during program initialization. Loading the kernel using the SPICELIB routine FURNSH causes the data items and their associated values present in the kernel to become associated with a data structure called the ``kernel pool''. The application program may then obtain the value(s) for any IK data item using the SPICELIB routines GDPOOL, GIPOOL, GCPOOL. Routine GETFOV may also be used if the file contains instrument field-of-view (FOV) specifications. See [1] for details. This file was created with, and can be updated with a text editor or word processor. 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 MEX instrument ID code, constructed using the spacecraft ID number (-41) followed by the NAIF three digit ID number for ASPERA (100), ASPERA base (110), ASPERA scanner (111), or one of its detectors -- Electron Spectrometer, ELS (120), Neutral Particle Imager, NPI (130), Neutral Particle Detector, NPD (140), or Ion Mass Analyser, IMA (150). These IDs are defined in [4] as follows: Instrument name ID -------------------- ------ MEX_ASPERA -41100 MEX_ASPERA_BASE -41110 MEX_ASPERA_SCANNER -41111 MEX_ASPERA_ELS -41120 MEX_ASPERA_NPI -41130 MEX_ASPERA_NPD -41140 MEX_ASPERA_IMA -41150 The remainder of the keyword is an underscore character followed by the unique name of the data item. For example, the number of sectors in the NPI FOV is specified by INS-41130_NUMBER_OF_SECTORS The upper bound on the length of all keywords is 32 characters. If a keyword is included in more then one file, or if the same keyword appears more than once within a single file, the last assignment supersedes any earlier assignments. Overview -------------------------------------------------------- From [TBD]: "ASPERA description. To be copied from TBD source provided by the ASPERA team." Mounting Alignment -------------------------------------------------------- Refer to the latest version of the Mars Express Frames Definition Kernel (FK) [4] for the ASPERA reference frame definitions and mounting alignment information. Detector Layout -------------------------------------------------------- This section contains assignments specifying the detector layout by defining individual sector view directions for each of the ASPERA detectors -- ELS, NPI, NPD, and IMA. The combined field-of-view (FOV) of each of the detectors is broken down into a number of equally or unequally spaced sectors to achieve the necessary spatial resolution within the detector's sensor plane and in the direction normal to it (applicable for IMA only, since for the other detectors the cross-plane spatial resolution is achieved by scanning.) This table summarizes the individual detector sector layout: --------- --------------------- --------------------- Detector Number of Sectors Sector size, deg Name in-plane cross-plane in-plane cross-plane --------- -------- ----------- -------- ----------- ELS 16 1 22.5 4.0 NPI 32 1 18.0 9.0 NPD 6 1 30.0 9.0 IMA 16 20 22.5 4.5 --------- --------------------- --------------------- The parameters from the table are provided for each detector using the following keywords: NUMBER_OF_SECTORS -- contains two integers for in-plane and cross-plane sector numbers SECTOR_SIZE -- contains two numbers for in-plane and cross-plane sector size, in degrees FRAME -- contains the name of the frame in which the sector view directions are defined SECTOR_DIRECTIONS -- contains sector center view directions for each sector in the sensor symmetry plane. (Note that this keyword does not provide the direction of all 320 IMA sectors but ONLY for the 16 located in the symmetry plane.) For consistency the order of vectors in the SECTOR_DIRECTIONS is the same for all detectors -- clockwise starting with the sector closest to the detector frame's Z axis. ELS Sector Layout The ELS's 360.0 x 4.0 degrees FOV is split into 16 22.5 x 4.0 degrees sectors. All sector view directions are assumed to be equally spaced within the YZ plane of the MEX_ASPERA_ELS frame. The boundary between sectors 1 and 16 is assumed to be coincident with the frame's Z axis, thus the "first" sector view direction is 11.25 degrees off the +Z axis. \begindata INS-41120_NUMBER_OF_SECTORS = ( 16, 1 ) INS-41120_SECTOR_SIZE = ( 22.5, 4.0 ) INS-41120_FRAME = 'MEX_ASPERA_ELS' INS-41120_SECTOR_DIRECTIONS = ( 0.00000000 0.19509032 0.98078528 0.00000000 0.55557023 0.83146961 0.00000000 0.83146961 0.55557023 0.00000000 0.98078528 0.19509032 0.00000000 0.98078528 -0.19509032 0.00000000 0.83146961 -0.55557023 0.00000000 0.55557023 -0.83146961 0.00000000 0.19509032 -0.98078528 0.00000000 -0.19509032 -0.98078528 0.00000000 -0.55557023 -0.83146961 0.00000000 -0.83146961 -0.55557023 0.00000000 -0.98078528 -0.19509032 0.00000000 -0.98078528 0.19509032 0.00000000 -0.83146961 0.55557023 0.00000000 -0.55557023 0.83146961 0.00000000 -0.19509032 0.98078528 ) \begintext NPI Detector Layout The NPI's 360.0 x 9.0 degrees FOV is split into 32 sectors. While each sector's aperture is 18.0 x 9.0 degrees, the sector view directions are only 11.25 degrees apart. All sector view directions are assumed to be equally spaced within the YZ plane of the MEX_ASPERA_NPI frame. The boundary between sectors 1 and 32 is assumed to be coincident with the frame's Z axis, thus the "first" sector view direction is 5.625 degrees off the +Z axis. \begindata INS-41130_NUMBER_OF_SECTORS = ( 32, 1 ) INS-41130_SECTOR_SIZE = ( 18.0, 9.0 ) INS-41130_FRAME = 'MEX_ASPERA_NPI' INS-41130_SECTOR_DIRECTIONS = ( 0.00000000 0.09801714 0.99518473 0.00000000 0.29028468 0.95694034 0.00000000 0.47139674 0.88192126 0.00000000 0.63439328 0.77301045 0.00000000 0.77301045 0.63439328 0.00000000 0.88192126 0.47139674 0.00000000 0.95694034 0.29028468 0.00000000 0.99518473 0.09801714 0.00000000 0.99518473 -0.09801714 0.00000000 0.95694034 -0.29028468 0.00000000 0.88192126 -0.47139674 0.00000000 0.77301045 -0.63439328 0.00000000 0.63439328 -0.77301045 0.00000000 0.47139674 -0.88192126 0.00000000 0.29028468 -0.95694034 0.00000000 0.09801714 -0.99518473 0.00000000 -0.09801714 -0.99518473 0.00000000 -0.29028468 -0.95694034 0.00000000 -0.47139674 -0.88192126 0.00000000 -0.63439328 -0.77301045 0.00000000 -0.77301045 -0.63439328 0.00000000 -0.88192126 -0.47139674 0.00000000 -0.95694034 -0.29028468 0.00000000 -0.99518473 -0.09801714 0.00000000 -0.99518473 0.09801714 0.00000000 -0.95694034 0.29028468 0.00000000 -0.88192126 0.47139674 0.00000000 -0.77301045 0.63439328 0.00000000 -0.63439328 0.77301045 0.00000000 -0.47139674 0.88192126 0.00000000 -0.29028468 0.95694034 0.00000000 -0.09801714 0.99518473 ) \begintext NPD Detector Layout The NPD's 180.0 x 9.0 degrees FOV is split into 6 sectors that are 30 degrees apart. Each sector's aperture is 30.0 x 9.0 degrees. All sector view directions are assumed to be equally spaced in the +Z half of the YZ plane of the MEX_ASPERA_NPD frame. The boundary between sectors 1 and 6 is assumed to be coincident with the frame's Z axis, thus the "first" sector view direction is 15.0 degrees off the +Z axis. \begindata INS-41140_NUMBER_OF_SECTORS = ( 6, 1 ) INS-41140_SECTOR_SIZE = ( 30.0, 9.0 ) INS-41140_FRAME = 'MEX_ASPERA_NPD' INS-41140_SECTOR_DIRECTIONS = ( 0.00000000 0.25881905 0.96592583 0.00000000 0.70710678 0.70710678 0.00000000 0.96592583 0.25881905 0.00000000 -0.96592583 0.25881905 0.00000000 -0.70710678 0.70710678 0.00000000 -0.25881905 0.96592583 ) \begintext IMA Detector Layout The IMA's 360.0 x 90.0 degrees FOV is split into 320 sectors -- 16 (in-plane) by 20 (cross-pane) -- 22.5 x 4.5 degrees each. The "in-plane" sector view directions are assumed to be equally spaced in the YZ plane of the MEX_ASPERA_IMA frame. The boundary between sectors 1 and 16 is assumed to be coincident with the frame's Z axis, thus the "first" sector view direction is 11.25 degrees off the +Z axis. \begindata INS-41150_NUMBER_OF_SECTORS = ( 16, 20 ) INS-41150_SECTOR_SIZE = ( 22.5, 4.5 ) INS-41150_FRAME = 'MEX_ASPERA_IMA' INS-41150_SECTOR_DIRECTIONS = ( 0.00000000 0.19509032 0.98078528 0.00000000 0.55557023 0.83146961 0.00000000 0.83146961 0.55557023 0.00000000 0.98078528 0.19509032 0.00000000 0.98078528 -0.19509032 0.00000000 0.83146961 -0.55557023 0.00000000 0.55557023 -0.83146961 0.00000000 0.19509032 -0.98078528 0.00000000 -0.19509032 -0.98078528 0.00000000 -0.55557023 -0.83146961 0.00000000 -0.83146961 -0.55557023 0.00000000 -0.98078528 -0.19509032 0.00000000 -0.98078528 0.19509032 0.00000000 -0.83146961 0.55557023 0.00000000 -0.55557023 0.83146961 0.00000000 -0.19509032 0.98078528 ) \begintext Scanner Characteristics -------------------------------------------------------- The following essential parameters of the ASPERA main unit scanner are taken from [3]: ----------------------------- ----------- ------- Parameter name Value Unit ----------------------------- ----------- ------- maximum angle of rotation +/-100.00 deg angular position resolution 0.05 deg operational rotation rate 1.0/3.0/6.0 deg/sec maximum rotation rate 25.0 deg/sec ----------------------------- ----------- ------- The parameters are provided in the assignments below using the same units as in the table. \begindata INS-41111_ROTATION_RANGE = ( -100, 100 ) INS-41111_POSITION_ACCURACY = ( 0.05 ) INS-41111_ROTATION_RATE = ( 1.0, 3.0, 6.0 ) INS-41111_ROTATION_RATE_MAX = ( 25.0 ) \begintext Platform ID --------------------------------------------------------------------------- This number is the NAIF instrument ID of the platform on which the different parts of the instrument are mounted. ASPERA as a whole, its base, and IMA are mounted on the spacecraft; the scanner is attached to the base; the other three detectors -- NPI, NPD, and ELS -- are attached to the scanner. \begindata INS-41100_PLATFORM_ID = ( -41000 ) INS-41110_PLATFORM_ID = ( -41000 ) INS-41150_PLATFORM_ID = ( -41000 ) INS-41111_PLATFORM_ID = ( -41110 ) INS-41120_PLATFORM_ID = ( -41111 ) INS-41130_PLATFORM_ID = ( -41111 ) INS-41140_PLATFORM_ID = ( -41111 ) \begintext