DATA_OBJECT_TYPE = SPICE_I-KERNEL MISSION_ID = 1 SPACECRAFT_NAME = GALILEO SPACECRAFT_NUMBER = 77 INSTRUMENT_ID = 28 PROCESS_TIME = 1990-11-08T12:00:00 HIC I-KERNEL =========================================================================== This I-kernel contains instrument pointing information for the Heavy Ion Counter (HIC) instrument on board the Galileo spacecraft. The HIC instrument consists of two basic detector telescopes labled Low Energy Telescope E (LET E) and Low Energy Telescope B (LET B). An array of solid-state detectors are contained in each 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. ``Galileo Orbiter Flight Equipment: Energetic Particle Detector Subsystem'' in GALILEO FUNCTIONAL REQUIREMENTS BOOK, JPL Document GLL-4-2028A. 5. ``Galileo HIC Specifications'', by Jim Willet, NAIF Document number 208.0. 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 the 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 ( 'GLL28001.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 HIC 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 maximum acceptance angle for the LET B telescope is specified by INS-77028_MAX_ACCEP_ANG_B 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. DATA -------------------------------------------------------- Both of the telescopes are single ended. The boresight vectors for the two telescopes are given with respect to the spacecraft rotor Xr, Yr, and Zr axes. \begindata INS-77028_LET_B_BORESIGHT = ( 0.68, 0.68, -0.26 ) INS-77028_LET_E_BORESIGHT = ( 0.68, 0.68, -0.26 ) \begintext The LET B telescope contains 4 detectors: LB1, LB2, LB3, and LB4. The geometry of LB2 and LB3 limit the maximum acceptance angle to 25 degrees off axis. \begindata INS-77028_LET_B_ACCEP_ANG = ( 25.0 ) \begintext The LET E telescope contains five detectors: LE1, LE2, LE3, LE4, and LE 5. The LE1 and LE2 detectors define a 50 degree viewing cone (maximum acceptance angle of 25 degrees off axis) while the LE2 and LE5 define a 92 degrees viewing cone (maximum acceptance angle of 46 degrees off axis). \begindata INS-77028_LET_E_ACCEP_ANG = ( 25.0, 46.0 ) \begintext Date on which the above data was entered into this I-kernel. \begindata INS-77028_DATA_ENTRY_DATE = ( @19-OCT-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-77028_VERSION = ( 1.0 )