General information about SPICE C-kernels ========================================= In the SPICE system, pointing data for an instrument platform, or for a specific instrument, are stored in C-kernels. The pointing of a platform or an instrument is often expressed in terms of a transformation matrix from some standard inertial reference frame to a instrument-fixed frame. In the past, the instrument was often a camera, and the transformation was thus dubbed the ``C-matrix''; hence the choice of C as the name for the pointing kernel. CKs can be accessed by subroutines that are part of the SPICE library, the major component of the SPICE Toolkit. These subroutines can be integrated into user application programs. For information on the SPICE Toolkit and/or how to obtain it, please consult SPICE_INST.CAT and SOFT.CAT. To use C-kernels, a Spacecraft Clock Kernel (SCLK) is required. Also, for C-Kernels containing orientation of a project-defined frame, a Frame Definitions File (FK) is required. Refer to the CK.REQ and FRAMES.REQ documents provided with the Toolkit or available from the NAIF Node of PDS to get more information on how to access C-kernel data. ROSETTA C-Kernel Files ====================== This file describes the contents of the DATA/CK directory of the ROSETTA SPICE data set. The contents and time span covered by any CK file may be easily determined using the 'ckbrief' utility program available in all copies of the SPICE Toolkit. Example: %ckbrief This utility requires additionally a SCLK file and a LSK file; use the latest versions of these files. Descriptive information about how/why/when a CK file was created is usually available in the 'comment area' of the file. This may be viewed using the 'commnt' utility program available in all the SPICE Toolkits. Use the '-r' option to read the comments. Example: %commnt -r All binary CK files (*.BC) contained in this directory are little-endian (LTL-IEEE) binary files. Rosetta C-kernels contained on this data set ============================================ The following ROSETTA C-kernels are provided in this data set: Rosetta Orbiter Orientation CKs: RATT_DV_145_01_01____00216.BC RATT_DV_223_01_01____00302.BC RATT_DV_257_02_01____00344.BC RATT_DV_145_01_01_T6_00216.BC RATT_DV_223_01_01_T6_00302.BC RATT_DV_257_02_01_T6_00344.BC Contains the orientation of the Rosetta orbiter frame ('ROS_SPACECRAFT') during orbital operations, based on data provided by ESOC. ATNR_P040302093352_00046.BC ATNR_P040302093352_00096.BC ATNR_P040302093352_00109.BC ATNR_P040302093352_00127.BC ATNR_P040302093352_T6_00127.BC Contain the orientation of the Rosetta orbiter frame ('ROS_SPACECRAFT'), covering from launch to the comet rendezvous maneuver, based on data provided by ESOC. The file with the latest version supersedes all previous versions. ROS_ORBITER_EXTENSION_V2.BC Contains the orientation of the Rosetta orbiter frame ('ROS_SPACECRAFT') after end of mission with a constant attitude defined by the last datapoint of RATT_DV_257_02_01_T6_00344.BC. ROS_OSIRIS_V2.BC Contains the best estimate of the NAC and WAC frames ('ROS_OSIRIS_NAC' and 'ROS_OSIRIS_WAC') orientation created by ESA SPICE Service based on data from MPS. ROS_SC_MES_050501_060101_V03.BC ROS_SC_MES_060101_070101_V03.BC ROS_SC_MES_070101_080101_V03.BC ROS_SC_MES_080101_090101_V03.BC ROS_SC_MES_090101_100101_V03.BC ROS_SC_MES_100101_110101_V03.BC ROS_SC_MES_110101_110608_V03.BC ROS_SC_MES_140120_150101_V03.BC ROS_SC_MES_150101_160101_V03.BC ROS_SC_MES_160101_160930_V03.BC Contain the "measured" orientation of the Rosetta orbiter frame ('ROS_SPACECRAFT') obtained from Housekeeping Telemetry. ROS_SC_DLR_S4S_1408_1409_V1.BC This CK contains 251 Type 3 CK segments each covering a two-second interval corresponding to one of OSIRIS images taken in August-September 2014 and used in producing the SHAP4S shape model. ROS_SC_REC_140801_141231_V01.BC ROS_SC_REC_150101_151231_V01.BC ROS_SC_REC_160101_160601_V01.BC Contains Rosetta reconstructed attitude information. This attitude has been reconstruced by Bjoern Grieger using OSIRIS and NAVCAM images of the comet nucleus. Note that these CKs show a discrepancy of around 5 mdeg during slews with respect to the predicted CKs from Flight Dynamics. Rosetta Lander Orientation CKs: LATT_ROS2LDR_PRESEP_V1_0.BC Contains Rosetta Lander orientation before the Lander separation from the Rosetta Orbiter. The Rosetta Lander is attached to the Rosetta Orbiter. LATT_CFF2LDR_FSS_V2_0.BC Contains Rosetta Lander attitude for the First Science Sequence and beyond (until EOM). The data was provided by SONC-FD. LATT_EME2LDR_SDL_V1_0.BC Contains Rosetta Lander attitude for the Separation, Descent and First Landing as defined by the data was by SONC-FD. LATT_ROS2LDR_SDL_ROMAP_V1_0.BC Contains Rosetta Lander attitude for the Separation, Descent and First Landing as defined by the data was by ROMAP. Comet 67P/C-G Orientation CKs: CATT_DV_145_01_______00216.BC CATT_DV_145_02_______00216.BC CATT_DV_223_02_______00302.BC CATT_DV_257_03_______00344.BC Contains the orientation of the comet 67P/C-G body-fixed frame ('67P/C-G_CK'), based on data provided by ESOC. CATT_CHEOPS__110325_110326.BC Contains comet attitude, for a limited period of time as provided by the PCK that contains the "Cheops reference frame" orientation information. This kernel provides the comet attitude in the frame 67P/C-G_CK. VIRTIS-M Orientation CKs: ROS_VIRTIS_M_0403_1509_V1.BC ROS_VIRTIS_M_1509_1609_V1.BC Contains the actual orientation of the VIRTIS-M articulating frame ('ROS_VIRTIS-M_SCAN'), created by merging individual CKs produced by the VIRTIS team. ROS_VIRTIS_ZERO_V1.BC Contains the fictitious orientation of the VIRTIS-M articulating frame ('ROS_VIRTIS-M_SCAN') at "zero" position. This can be used only for applications for which assuming that VIRTIS-M mirror was at zero position is acceptable. High Gain Antenna Orientation CKs: ROS_HGA_2004_V0001.BC ROS_HGA_2004_V0002.BC ROS_HGA_2005_V0001.BC ROS_HGA_2005_V0002.BC ROS_HGA_2006_V0001.BC ROS_HGA_2006_V0002.BC ROS_HGA_2007_V0001.BC ROS_HGA_2007_V0002.BC ROS_HGA_2008_V0018.BC ROS_HGA_2008_V0019.BC ROS_HGA_2008_V0020.BC ROS_HGA_2009_V0051.BC ROS_HGA_2009_V0052.BC ROS_HGA_2009_V0053.BC ROS_HGA_2010_V0042.BC ROS_HGA_2010_V0046.BC ROS_HGA_2010_V0047.BC ROS_HGA_2011_V0018.BC ROS_HGA_2011_V0019.BC ROS_HGA_2014_V0044.BC ROS_HGA_2014_V0045.BC ROS_HGA_2015_V0038.BC ROS_HGA_2015_V0053.BC ROS_HGA_2015_V0054.BC ROS_HGA_2016_V0042.BC ROS_HGA_2016_V0043.BC Contain the orientation of the Rosetta High Gain Antenna frames ('ROS_HGA_EL' and 'ROS_HGA_AZ'), in yearly chunks. For each year, the file with the latest version supersedes all files with earlier versions. Solar Array Orientation CKs: ROS_SA_2004_V0001.BC ROS_SA_2004_V0002.BC ROS_SA_2005_V0001.BC ROS_SA_2005_V0002.BC ROS_SA_2006_V0001.BC ROS_SA_2006_V0002.BC ROS_SA_2007_V0001.BC ROS_SA_2007_V0002.BC ROS_SA_2008_V0038.BC ROS_SA_2008_V0039.BC ROS_SA_2009_V0054.BC ROS_SA_2009_V0055.BC ROS_SA_2010_V0043.BC ROS_SA_2010_V0052.BC ROS_SA_2010_V0053.BC ROS_SA_2011_V0020.BC ROS_SA_2011_V0021.BC ROS_SA_2014_V0047.BC ROS_SA_2014_V0048.BC ROS_SA_2015_V0037.BC ROS_SA_2015_V0042.BC ROS_SA_2015_V0043.BC ROS_SA_2016_V0041.BC ROS_SA_2016_V0042.BC Contain the orientation of the Rosetta Solar Arrays frames ('ROS_SA+Y' and 'ROS_SA-Y'), in yearly chunks. For each year, the file with the latest version supersedes all files with earlier versions. RPC Boom 2 Orientation CKs: ROS_LBOOM_V0.BC Contain the orientation of the RPC boom 2 frame ('ROS_RPC_BOOM2'). Kernel File Details =================== The most detailed description of the data in a binary CK file is provided in metadata included inside the comment area of the file. This information can be viewed using utility programs 'commnt' and 'spacit' included into the SPICE Toolkit. At least a basic knowledge of the SPICE system is needed in order to use these kernels. The SPICE Toolkit provides versions in Fortran (SPICELIB), C (CSPICE), IDL (Icy), Matlab (Mice), and Java (JNISpice) and the user can choose any one that suits him/her. The SPICE routine FURNSH can be used to load a kernel file into a SPICE-based application to make kernel data usable with SPICE APIs. In the case when two or more binary CK files contain data overlapping in time for a given object the file loaded last takes precedence. Please note that CKs that contain 'T6' in their filename indicate that they are Type 6 CKs as opposed to type 5. T6 CKs contain the same data as their non-T6 counterparts but they have precedence due to computational efficiency (although they require Toolkit version N0065 or higher).