KPL/FK Frame (FK) SPICE kernel file for Ramses science operations frames =============================================================================== This frames kernel defines a number of frames used by the Ramses science operations centre to perform mission analysis and attitude dependent science opportunity identification. These frames can be used stand-alone, i.e. referring directly to them and assuming they correspond to the Ramses spacecraft reference frame, or in combination with the Ramses spacecraft frames. The latter will allow the user to use the existing alignments and instrument frame definitions to perform instrument specific mission analysis and attitude dependent science opportunity identification. Please refer to the section ``Using these frames'' for further details. Version and Date ------------------------------------------------------------------------------- Version 0.0 -- March 28, 2025 -- Alfredo Escalante Lopez, ESAC/ESA Initial version. References ------------------------------------------------------------------------------- [1] "Frames Required Reading" [2] "Kernel Pool Required Reading" Contact Information ----------------------------------------------------------------------------- If you have any questions regarding this file contact the ESA SPICE Service at ESAC: Alfredo Escalante Lopez (+34) 91-8131-429 spice@sciops.esa.int or NAIF at JPL: Boris Semenov +1 (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 frame kernel must "load" the kernel normally during program initialization. Loading the kernel associates the data items with their names in a data structure called the "kernel pool". The SPICELIB routine FURNSH loads a kernel into the pool 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' ) PYTHON: (SPICEYPY)* furnsh( frame_kernel_name ) In order for a program or routine to extract data from the pool, the SPICELIB routines GDPOOL, GIPOOL, and GCPOOL are used. See [2] for more details. This file was created and may be updated with a text editor or word processor. * SPICEPY is a non-official, community developed Python wrapper for the NAIF SPICE toolkit. Its development is managed on Github. It is available at: https://github.com/AndrewAnnex/SpiceyPy Ramses Science Operations frame names and NAIF ID Codes ------------------------------------------------------------------------------- The following frame is defined in this kernel file: SPICE Frame Name Long-name ------------------------ --------------------------------------------- RAMSES_APOPHIS_NPO Ramses Apophis Nadir power-optimized pointing These frame has the following centers, frame class and NAIF ID: SPICE Frame Name Center Class NAIF ID ------------------------ --------------------- ------- --------- RAMSES_APOPHIS_NPO RAMSES DYNAMIC -92912 General Notes About This File ------------------------------------------------------------------------------- About Required Data: -------------------- All the dynamic frames defined in this file require at least one of the following kernel types to be loaded prior to their evaluation, normally during program initialization: - Planetary and Satellite ephemeris data (SPK), i.e. de432, de405, etc; - Spacecraft ephemeris data (SPK); Note that loading different kernels will lead to different orientations of the same frame at a given epoch, providing different results from each other, in terms of state vectors referred to these frames. Using these frames ------------------ These frames have been implemented to define the different pointing profiles for the Ramses spacecraft. These pointing profiles can be used in two different ways: [1] ``As is'' for analysis of offsets between the spacecraft attitude defined in the corresponding CK and a given pointing profile. Loading this kernel in combination with any Ramses CK will allow the user to perform this comparison between the RAMSES_SPACECRAFT frame and any of the different frames defined within this kernel. [2] In combination with the Ramses Frames kernel, to define a default pointing profile for the whole duration of the mission together with the spacecraft and instrument frames defined in the Ramses FK. In this way, instrument-specific mission analysis activities, for which a particular pointing profile and knowledge of the instruments is required, can be conducted without the need for a spacecraft CK. In order to define such default pointing profile, the latest Ramses frames kernel and this file shall be loaded before the selected ``Ramses spacecraft frame overwrite'' frame kernel. As an example, imagine that the desired default pointing profile is "Nadir power optimized with respect to Apophis", then the furnish (metakernel) file should contain the following sequence of frames kernels, in the following order: ... $DATA/fk/ramses_v00.tf $DATA/fk/ramses_ops_v00.tf $DATA/fk/ramses_sc_apophis_npo_v00.tf ... (*) the example presents version 0.0 of the Ramses frames and Ramses Science Operations frames kernels. Newer versions of these files will produce the same results. By loading the ``ramses_sc_apophis_npo_vNN.tf'' frames kernel last, the spacecraft frame RAMSES_SPACECRAFT, which is defined as a CK-based frame in the ``Ramses frames kernel'', will be overwritten as a type-4 fixed offset frame, mapping the RAMSES_SPACECRAFT frame to the RAMSES_APOPHIS_NPO frame defined in the ``Ramses Science Operations Frames Kernel'' (this) file. Ramses Science Operations Frame Definitions ------------------------------------------------------------------------------- This section contains the definition of the Ramses science operations frames. Ramses Apophis Nadir power-optimized pointing frame (RAMSES_APOPHIS_NPO) --------------------------------------------------------------------- Definition: ----------- The Ramses Apophis Nadir power-optimized pointing frame is defined as follows: - +Z axis is the primary vector and points from Ramses to the center of Apophis (Nadir direction); - +X axis is the secondary vector and points from Ramses to the Sun; - +Y axis completes the right-handed system; - the original of this frame is the spacecraft's center of mass. All vectors are geometric: no corrections are used. Required Data: -------------- This frame is defined as a two-vector frame. Both the primary and the secondary vector are defined as an 'observer-target position' vectors, therefore, the ephemeris data required to compute both the Ramses-Apophis position and the Ramses-Sun position in J2000 frame have to be loaded before using this frame. Remarks: -------- Since the primary and secondary vectors of this frame are defined based on the Ramses-Apophis position and Ramses-Sun position vectors, the usage of different ephemerides to compute these vectors may lead to different frame orientation at given time. \begindata FRAME_RAMSES_APOPHIS_NPO = -92912 FRAME_-92912_NAME = 'RAMSES_APOPHIS_NPO' FRAME_-92912_CLASS = 5 FRAME_-92912_CLASS_ID = -92912 FRAME_-92912_CENTER = -92 FRAME_-92912_RELATIVE = 'J2000' FRAME_-92912_DEF_STYLE = 'PARAMETERIZED' FRAME_-92912_FAMILY = 'TWO-VECTOR' FRAME_-92912_PRI_AXIS = 'Z' FRAME_-92912_PRI_VECTOR_DEF = 'OBSERVER_TARGET_POSITION' FRAME_-92912_PRI_OBSERVER = 'RAMSES' FRAME_-92912_PRI_TARGET = 'APOPHIS' FRAME_-92912_PRI_ABCORR = 'NONE' FRAME_-92912_SEC_AXIS = 'X' FRAME_-92912_SEC_VECTOR_DEF = 'OBSERVER_TARGET_POSITION' FRAME_-92912_SEC_OBSERVER = 'RAMSES' FRAME_-92912_SEC_TARGET = 'SUN' FRAME_-92912_SEC_ABCORR = 'NONE' FRAME_-92912_SEC_FRAME = 'J2000' \begintext End of FK file.