DAWN CK files. =========================================================================== This ``aareadme.txt'' file describes contents of the kernels/ck directory of the DAWN SPICE data server. It was last modified on December 20, 2007. Contact Chuck Acton (818-354-3869, Chuck.Acton@jpl.nasa.gov) or Boris Semenov (818-354-8136, Boris.Semenov@jpl.nasa.gov) if you have any questions regarding this data. Brief summary -------------------------------------------------------- This directory contains the SPICE C-Kernel files for the DAWN spacecraft and its solar arrays. The following files are present in this directory. (Only file names are shown; the file name extensions of the binary CK files are always ``.bc'') Reconstructed CK files dawn_sc_YYMMDD_YYMMDD Regular weekly reconstructed DAWN spacecraft orientation CK files produced by NAIF/JPL. Each of these files covers seven days identified in the file name. The files are delivered weekly, three days after the end date of the file coverage. During mission phases with sparse DSN coverage each of these files is re-generated and replaced two times, 10 and 17 days after end date of the file coverage. dawn_sc_YYYY-MM-DD Regular daily reconstructed DAWN spacecraft orientation CK files produced by NAIF/JPL. Each of these files covers one day identified in the file name. The files are delivered daily with a two day delay. dawn_sa_YYMMDD_YYMMDD Regular weekly reconstructed DAWN solar array orientation CK files produced by NAIF/JPL. Each of these files covers seven days identified in the file name. The files are delivered weekly, three days after the end date of the file coverage. During mission phases with sparse DSN coverage each of these files is re-generated and replaced two times, 10 and 17 days after end date of the file coverage. dawn_sa_YYYY-MM-DD Regular daily reconstructed DAWN solar array orientation CK files produced by NAIF/JPL. Each of these files covers one day identified in the file name. The files are delivered daily with a two day delay. Predicted CK files None Test CK Files dawn_sc_TDS_ert_BEG_END Test DAWN spacecraft orientation CK files produced by NAIF/JPL. These files are produced only in special cases, in support of some tests, when requested by the science teams. They provide attitude data from test bed TDS identified by file name token TDS for the ERT time range from BEG to END, with BEG and END specified as YYMMDDHRMN. dawn_sa_TDS_ert_BEG_END Test DAWN solar arrays orientation CK files produced by NAIF/JPL. These files are produced only in special cases, in support of some tests, when requested by the science teams. They provide attitude data from test bed TDS identified by file name token TDS for the ERT time range from BEG to END, with BEG and END specified as YYMMDDHRMN. CK File Naming Schema. -------------------------------------------------------- The subsections below describe CK file naming schemes. Regular Reconstructed Weekly CK Files. The reconstructed spacecraft and solar array orientation weekly CK files are automatically created by NAIF from the spacecraft engineering telemetry (orientation quaternions, spacecraft angular rates and solar array gimbal angles) on a weekly basis during all mission phases. These files are automatically transferred to the server right after creation. These files are intended for OPS use and for archiving in PDS. The file names for these CKs have the following format: dawn_XXX_YYMMDD_yymmdd where XXX is the structure id: ``sc'' for spacecraft, ``sa'' for sa; YYMMDD is the first day covered by the file; yymmdd is the last day covered by the file; Regular Reconstructed Daily CK Files. The reconstructed spacecraft and solar array orientation daily CK files are automatically created by NAIF from the spacecraft engineering telemetry (orientation quaternions, spacecraft angular rates and solar array gimbal angles) on a daily basis only during mission phases with continuous or nearly continuous DSN coverage. These files are automatically transferred to the server right after creation. The file names for the regular reconstructed spacecraft and SA CKs have the following format: dawn_XXX_YYYY-MM-DD[_yyyy-mm-dd][_zzz] where XXX is the structure id: ``sc'' for spacecraft, ``sa'' for sa; YYYY-MM-DD is the (first) day covered by the file; yyyy-dd-dd is the last day covered by the file (usually omitted because nominally each file covers only one day); zzz is an optional identifier for CKs generated for special purposes; Test CK Files. The test CKs files are created by NAIF on as needed basis. The file names for the test CKs have the following format: dawn_XXX_TDS_TT_YYMMDDHRMN_yymmddhrmn where XXX is the structure id: ``sc'' for spacecraft, ``sa'' for sa; TB is the name of the test TDS from which the data was obtained. TT is the data query time type (``ert'' or ``scet''). YYMMDDHRMN is the data query begin time. yymmddhrmn is the data query end time.