KPL/IK RIME Instrument Kernel =============================================================================== This instrument kernel (I-kernel) contains the Radar for Icy Moon Exploration (RIME) radar field-of-view (FOV) paramters. Version and Date ------------------------------------------------------------------------------- Version 0.2 -- May 11, 2016 -- Jorge Diaz del Rio, ODC Space Added instrument description. Preliminary version. Pending review by the RIME instrument team. Version 0.1 -- April 25, 2016 -- Jorge Diaz del Rio, ODC Space Initial Release. Pending review by the RIME instrument and JUICE Science Operations Working Group teams. Version 0.0 -- July 24, 2013 -- Marc Costa Sitja, ISDEFE/ESA Initial Release. References ------------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading'' 2. ``C-kernel Required Reading'' 3. JUICE Frames Definition Kernel (FK), latest version. 4. ``JUICE - Jupiter Icy Moons Explorer. Exploring the emergence of habitable worlds around gas giants. Definition Study report,'' ESA/SRE(2014)1, September 2014 (JUICE Red book v1.0) 5. ``JUICE - Radar for Icy Moon Exploration (RIME) - Experiment Interface Document - Part B,'' JUI-UTR-RIM-EID-001 Issue 5.2, 01 December 2014 Contact Information ------------------------------------------------------------------------------- If you have any questions regarding this file contact SPICE support at ESAC: Marc Costa Sitja (+34) 91-8131-457 mcosta@sciops.esa.int, esa_spice@sciops.esa.int or NAIF at JPL: Boris Semenov (818) 354-8136 Boris.Semenov@jpl.nasa.gov Implementation Notes ------------------------------------------------------------------------------- Applications that need SPICE I-kernel data must ``load'' the I-kernel file, normally during program initialization. The SPICE routine FURNSH loads a kernel file into the pool as shown below. CALL FURNSH ( 'frame_kernel_name' ) -- FORTRAN furnsh_c ( "frame_kernel_name" ); -- C cspice_furnsh, frame_kernel_name -- IDL cspice_furnsh( 'frame_kernel_name' ) -- MATLAB 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''. Once the file has been loaded, the SPICE routine GETFOV (getfov_c in C, cspice_getfov in IDL and MATLAB) can be used to retrieve FOV parameters for a given instrument or structure. The application program may obtain the value(s) for any other IK data item using the SPICELIB routines GDPOOL, GIPOOL, GCPOOL (gdpool_c, gipool_c, gcpool_c in C, cspice_gdpool, cspice_gipool, cspice_gcpool in IDL and MATLAB). See [1] for details. This file was created with, and can be updated with a text editor or word processor. Naming Conventions and Conventions for Specifying Data ------------------------------------------------------------------------------- All names referencing values in this IK file start with the characters `INS' followed by the NAIF JUICE spacecraft ID number (-907) followed by a NAIF three digit ID code for the RIME instrument. This is the full list of names and IDs for the RIME instrument described by this IK file: Name NAIF ID --------------------- --------- JUICE_RIME -907600 The remainder of the keyword name is an underscore character followed by the unique name of the data item. For example, the RIME dipole boresight direction in the JUICE_RIME frame is specified by: INS-907600_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. Instrument Description and Overview ------------------------------------------------------------------------------- RIME instrument is optimised for the penetration of the Galilean icy moons, Ganymede, Europa and Callisto, up to a depth of 9 km (see [4]). RIME is a nadir-looking radar sounder instruments which transmits radio waves with the capability to penetrate deeply into the subsurface. When these radio waves travel through the subsurface, their reflected signal varies as they interact with subsurface horizons and structures with differing dielectric constants. These varying reflections are detected by the radar sounder and used to create a depth image of the subsurface (referred as radargram). The RIME central frequency is selected to be 9 MHz, which is an optimal choice for meeting the penetration requirements and for reducing the effect of clutter induced by the topography of Ganymede, Europa and Callisto surfaces. RIME is designed for achieving a maximum penetration depth of 9 km with two measurement modes that result in high vertical resolution (maximum of 50 m in ice with a chirp bandwidth of 3 MHz) or low vertical resolution (140 m in ice with a chirp bandwidth of 1 MHz). The RIME nominal data rate in the circular orbit phase around Ganymede is in the range 210-217 kbps depending on the measurement mode, whereas it is 2784 kbps during flybys. It is important to mention that within the high and low resolution modes, parameters can be adjusted to change the output data rate and obtain intermediate acquisition modes. The RIME antenna is a dipole with a tip-to-tip length of 16 m. The main parameters of RIME are shown in the following table: ---------------------------------------------------------- PARAMETER VALUE ------------------------------- ------------------------ Transmitted central frequency 9 MHz Antenna length 16 m Maximum penetration 9 km Cross-track resolution 2-10 km Along-track resolution 0.3-1.0 km Pulse repetition frequency 200-500Hz Chirp bandwidth 3, 1 MHz Vertical resolution in ice 50-140m Chirp length 50-100 microseconds Receiver window length 117-226 microseconds ---------------------------------------------------------- Two main operation scenarios are foreseen for RIME: flyby observations and orbital operations around Ganymede. Because flybys of Europa and Callisto provide unique scientific opportunities for RIME, it is considered desirable to downlink data in their simplest form, and to perform processing exclusively on the ground to achieve flexibility in the processing modes and thus to optimize science return. During the orbital phase at Ganymede, it is expected that the radar will routinely operate using modes employing on-board pre-summing for reducing the data rate. Mounting Alignment ------------------------------------------------------------------------------- Refer to the latest version of the JUICE Frames Definition Kernel (FK) [3] for the RIME reference frame definitions and mounting alignment information. RIME dipole Field of View Definition ------------------------------------------------------------------------------- The RIME dipole (JUICE_RIME) Field of View (FOV) is defined as a 40 degree half-angle cone centered on the +Z axis of the JUICE_RIME frame (see ref [5]). \begindata INS-907600_FOV_FRAME = 'JUICE_RIME' INS-907600_FOV_SHAPE = 'CIRCLE' INS-907600_BORESIGHT = ( 0.000, 0.000, 1.000 ) INS-907600_FOV_CLASS_SPEC = 'ANGLES' INS-907600_FOV_REF_VECTOR = ( 1.000, 0.000, 0.000 ) INS-907600_FOV_REF_ANGLE = ( 40.0 ) INS-907600_FOV_ANGLE_UNITS = 'DEGREES' \begintext