DATA_OBJECT_TYPE = SPICE_I-KERNEL MISSION_ID = 1 SPACECRAFT_NAME = GALILEO SPACECRAFT_NUMBER = 77 INSTRUMENT_ID = 37 PROCESS_TIME = 1990-11-12T12:00:00 NIMS I-kernel =========================================================================== This I-kernel contains Near Infrared Mapping Spectrometer (NIMS) instrument pointing information. The NIMS instrument consists of a gregorian telescope, a grating spectrometer, and an array of detectors in the focal plane. The instrument has a 5.0 x 0.25 mrad (0.0145 x 0.287 deg) FOV. The following instrument data is contained in this file. -- An offset of the NIMS boresight from the spacecraft L vector. -- Mirror position tables in cone and cross-cone for the various NIMS mirror states. -- Mode RIM tables which point to the correct mirror position table for each 1/2 minor frame (2/3 seconds) in a RIM (60 2/3 seconds). -- The focal length of the telescope. References -------------------------------------------------------- 1. ``Preliminary I-kernel Specification,'' (NAIF document number 177.0), by Ian Underwood, 1/19/90. 2. KERNEL ``Required Reading'' file. 3. ``Galileo Orbiter Flight Equipment: Configuration'' in GALILEO FUNCTIONAL REQUIREMENTS BOOK, JPL Document GLL-3-180C, 28 APR 1989. 4. ``The I-kernel Itself,'' JPL IOM, by R. Mehlman, 6/27/90 5. ``NIMS I-kernel Corrections,'' JPL IOM, by W. Smythe, 11/5/90 The two documents [4] and [5] comprise NAIF document number 207.0. Implementation Notes -------------------------------------------------------- This file is used by the SPICE system as follows: programs that make use of the I-kernel must `load' the kernel, normally during program initialization. Loading a kernel associates data items with their names in a data structure called the `kernel pool'. The SPICELIB routine LDPOOL loads a kernel file into the pool as shown below. CALL LDPOOL ( 'GLL37001.TI' ) In order for a program or subroutine to extract data from the pool, the SPICELIB routine RTPOOL is used. See [2] for more details. Naming Conventions -------------------------------------------------------- All names referencing values in this I kernel start with the characters `INS' followed by the NAIF NIMS instrument number ('-77' followed by the instrument subsystem reference number). This naming scheme is standard for all I-kernel files and was instituted to distinguish I-kernel data from other types of data that may also be loaded in the kernel pool. The remainder of the name is an underscore character, followed by the unique name of the data item. For example, the boresight cone offset for the NIMS instrument is specified by INS-77037_BORESIGHT_CONE_OFFSET The upper bound on the length of the name of any data item is 32 characters. If the same item is included in more then one file, or if the same item appears more than once within a single file, the latest value supersedes any earlier values. NIMS Assumptions -------------------------------------------------------- 1. NIMS boresight lies between MP 9 and 10 (MP 0-19) Presently defined to be 9.5. 2. NIMS boresight is displaced from the L vector (SSI boresight) by approximately 0.25 milliradians in both cone and cross-cone. There is an uncertainty in the sign of this displacement, therefore, this I-kernel assumes a value of zero in both directions. 3. The timing of the acquisition of data for a given mirror position assumes the end points are at the beginning of two minor frames. There are two pauses, one after mirror position 19 and one after mirror position 39. The ratios given are the fractional distance in time between the two end points. The first end point (0.0) is at the start of the first minor frame and the second end point (1.0) is at the start of the next minor frame. An example interpolation is shown for interpolating right ascension for a given mirror position: RAINT=RA(1)+(RA(2)-RA(1))*RATIO(MP+1) 4. The mirror is assumed to move in increments of pure cross cone. This I-kernel, however, does allow lookup for cone displacement - now assumed to be 0. 5. Each mirror displacement is 0.5283 milliradians. This is reflected in the cross-cone displacement table. 6. The mirror displacements are assumed to be independent of temperature. 7. The first mirror motion direction is down. Data -------------------------------------------------------- The NIMS boresight offset from the L vector has two values in milliradians: cone and cross cone. \begindata INS-77037_BORESIGHT_XCONE_OFFSET = 0.00 INS-77037_BORESIGHT_CONE_OFFSET = 0.00 \begintext The mirror position tables have 20 values each and cover the time interval of 1/2 minor frame. The tables give the mirror cross cone and cone offsets from the NIMS nominal boresight in milliradians. The nominal increment in cross cone is 0.5283 milliradians. The nominal increment in cone is 0.0 milliradians. The mirror position tables consist of the following (for both cone and cross-cone). Table 1 - SCAN DOWN Table 2 - SCAN UP Table 3 - WAIT Table 4 - STOP The boresight position is assumed to be 9.5. \begindata INS-77037_BORESIGHT_POSITION = ( 9.5 ) \begintext Mirror position table #1 ------------------------ \begindata INS-77037_POS_TBL_XCONE_DOWN = ( -5.019, -4.491, -3.962, -3.434, -2.906, -2.377, -1.849, -1.321, -0.792, -0.264, 0.264, 0.792, 1.321, 1.849, 2.377, 2.906, 3.434, 3.962, 4.491, 5.019 ) INS-77037_POS_TBL_CONE_DOWN = ( 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000 ) \begintext Mirror position table #2 ------------------------ \begindata INS-77037_POS_TBL_XCONE_UP = ( 5.019, 4.491, 3.962, 3.434, 2.906, 2.377, 1.849, 1.321, 0.792, 0.264, -0.264, -0.792, -1.321, -1.849, -2.377, -2.906, -3.434, -3.962, -4.491, -5.019 ) INS-77037_POS_TBL_CONE_UP = ( 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000 ) \begintext Mirror position table #3 ------------------------ \begindata INS-77037_POS_TBL_XCONE_WAIT = ( -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019, -5.019 ) INS-77037_POS_TBL_CONE_WAIT = ( 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000 ) \begintext Mirror position table #4 ------------------------ \begindata INS-77037_POS_TBL_XCONE_STOP = ( 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000 ) INS-77037_POS_TBL_CONE_STOP = ( 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000 ) \begintext Mirror sample timing table Assume the end points are at the beginning of two minor frames. There are two pauses, one after mirror position 19 and one after mirror position 39. The ratios given are the fractional distance in time between the two end points. The first end point (0.0) is at the start of the first minor frame and the second end point (1.0) is at the start of the next minor frame. An example interpolation is shown for interpolating right ascension for a given mirror position: RAINT=RA(1)+(RA(2)-RA(1))*RATIO(MP+1) \begindata INS-77037_TIME_TABLE = ( 0.00000000, 0.02380952, 0.04761905, 0.07142857, 0.09523810, 0.11904762, 0.14285715, 0.16666667, 0.19047619, 0.21428572, 0.23809524, 0.26190478, 0.28571430, 0.30952382, 0.33333334, 0.35714287, 0.38095239, 0.40476191, 0.42857143, 0.45238096, 0.50000000, 0.52380955, 0.54761904, 0.57142860, 0.59523809, 0.61904764, 0.64285713, 0.66666669, 0.69047618, 0.71428573, 0.73809522, 0.76190478, 0.78571427, 0.80952382, 0.83333331, 0.85714287, 0.88095236, 0.90476191, 0.92857140, 0.95238096 ) \begintext Mode RIM tables contain 182 entries corresponding to the mirror state for a given mode in a given 1/2 minor frame within a RIM. These tables merely point to the correct mirror position table for a given mode. These RIM tables are: LONG MAP FULL MAP SHORT MAP FIXED BANDEDGE SPECTROMETER (Valid for all grating cycle modes.) \begindata INS-77037_LONG_MAP = ( 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,3,3, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,3,3, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,3,3, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,3,3, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,3,3, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,3,3, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,3,3 ) INS-77037_FULL_MAP = ( 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3 ) INS-77037_SHORT_MAP = ( 1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3, 1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3, 1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3, 1,2,1,2,1,2,3, 1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3, 1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3, 1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3,1,2,1,2,1,2,3, 1,2,1,2,1,2,3 ) INS-77037_FIXED_MAP = ( 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3, 1,2,1,2,1,2,1,2,1,2,1,2,3,1,2,1,2,1,2,1,2,1,2,1,2,3 ) INS-77037_BANDEDGE_MAP = ( 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2, 1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2 ) INS-77037_SPECTROMETER_MAP = ( 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4 ) \begintext e. The focal length of the NIMS telescope is nominally 800 millimeters. \begindata INS-77037_FOCAL_LENGTH = 800.0 \begintext Date on which the above data was entered into this I-kernel: \begindata INS-77037_DATA_ENTRY_DATE = @05-NOV-1990 \begintext Version The version number is always positive and given in the form V.X. V and X are incremented by following these rules: -- V is incremented by 1 when there is a structural change to an I-kernel. A structural change to an instrument kernel would be adding or deleting data items or changing the number of values associated with an existing data item. A structural change would also be assigning different units to values or changing the name of a data item. -- X is incremented by 1 only if pre-existing values are changed. \begindata INS-77037_VERSION = 1.0