============================================================================= MEX CK Files ============================================================================= Last update: 10 NOV 2004 This "aareadme.txt" file describes the contents of the KERNELS/CK directory of the MEX SPICE data server. It also provides the file naming conventions used for the MEX CK kernels, and it provides identification of the most current version of each kind of CK file. All these CK files are produced by an automated system located at ESTEC, operated by the MEX Project Science Team (PST). We have chosen to use the ESOC naming convention for CK files, which are converted from ESOC's DDID Attitude files. Although this convention doesn't seem very descriptive and holds some redundant information, it could be useful to use the same name style for the sake of consistency. Also, data handling performed by the PST automated system will be easier and faster. There is an exception to the above mentioned. RECONSTITUTED data in ESOC's DDID format are converted to CK files using the Auxiliary Data Conversion System (ADCS) tool at ESTEC. Then the new CK files are appended to the existing "Reconstituted Data kernel file". The comment area of this kernel is updated every time new data are appended. This process is executed manually. The contents and time span covered by any CK file may be easily determined using the "brief" utility program available in all copies of the SPICE Toolkit. Examples of usage: %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 an 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 copies of the SPICE Toolkit. Use the "-r" option to read the comments. Example: %commnt -r All binary CK files (*.BC) contained in this directory are unix binary files. These may be used as is (without format conversion) in a non-unix environment when using any recent version of the SPICE Toolkit (Version N0052 or later). [Ref 3b] Contact Jorge Diaz del Rio (jdiaz@rssd.esa.int) or Joe Zender (Joe.Zender@esa.int) if you have any questions. ============================================================================= References ============================================================================= 1. Data Delivery Interface Document (DDID) Appendix H - FD products Issue 1.3 (MEX-ESC-IF-5003) 2. CK Required Reading. NAIF Document No. 174.08 05 Sep 2002 3. Selected SPICE Tutorials from the NAIF server: ftp://naif.jpl.nasa.gov/pub/naif/toolkit_docs/Tutorials/office/individual_docs a) CK Tutorial 15_ck.ppt b) Porting Kernels Tutorial 09_porting_kernels.ppt 4. NAIF IDs Required Reading. NAIF Document No. 219.12 30 Jul 2003 ============================================================================= Mars Express CK Directory Structure ============================================================================= aareadme.txt Text file describing the directory structure, the naming conventions for the CKs, and the current version(s) of each CK type. former_versions Subdirectory that contains obsolete versions of the CK files that have been updated in the Current CK Kernels Set. ============================================================================= MEX Spacecraft CK Naming Covention ffff_yYYMMDDhhmmss_vvvvv.ee ============================================================================= token description ------------ -------------------------------------------------- ffff Source Product Type Identifier: ATNM -- Predicted S/C attitude y Data Type Identifier P -- Predicted data YYMMDDhhmmss Coverage start time of the data contained in the ATNM file. vvvv version number ee NAIF File Name Extension -- "BC" (binary C kernel) ============================================================================= MEX "Planning CK" Naming Covention ffff_PTRvvvvv_YYMMDD_xxx.ee ============================================================================= token description ------------ -------------------------------------------------- ffff Source Product Type Identifier: ATNM -- Predicted S/C attitude vvvvv PTR version number YYMMDD Coverage start time of the data contained in the ATNM file. xxx file version number ee NAIF File Name Extension -- "BC" (binary C kernel) ============================================================================= Current CK Kernels Set ============================================================================= Name Comments -------------------------------- ------------------------------------- ATNM_PYYMMDDhhmmss_xxxxx.BC Contains Mars Express predicted attitude information covering the time span starting at the date YYMMDDhhmmss. This attitude information corresponds to the ESOC attitude file named: ATNM_FDLMMA_DAPYYMMDDhhmmss_xxxxx.MEX where xxxxx designates the version number. ATNM_PTRvvvvv_YYMMDD_xxx.BC Contains Mars Express predicted attitude information covering the time span starting at the date YYMMDD. This attitude information corresponds to the PTR file version vvvvv delivered from POS to ESOC and it is intended for the Teams to check the pointings. The final attitude file is fixed after iterating the PTR and it may differ from this "planning C-Kernel". ATNM_RECONSTITUTED_xxxxx.BC Contains Mars Express RECONSTITUTED attitude information. This attitude information corresponds to all reconstituted attitude files delivered from ESOC to PST. This file is updated every time new reconstituted data are available. The file contains gaps between data segments. Extensive documentation specifying valid interpolation intervals (periods with no data gaps) is provided in the comment area. Please refer to text above for information about using the COMMNT utility.