PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT INTERCHANGE_FORMAT = ASCII PUBLICATION_DATE = 2020-03-24 NOTE = "This file describes the files in the EXTRAS/MK directory of this archive." END_OBJECT = TEXT END Meta-kernels for the Venus Express mission ========================================== This directory contains the meta-kernel files (a.k.a "furnsh" files) that provide lists of the archived kernels included in this data set suitable for loading into a SPICE-based application via the high level SPICE data loader routine FURNSH. Using these meta-kernels makes it easy to load with one call a comprehensive SPICE data collection for a given period. Like the text kernels archived in this data set, these meta-kernels are UNIX text files that have lines terminated with a line feed character, LF (ASCII 10). The names of the meta-kernels provided in this directory follow this pattern: VEX_Vvv.TM where ``vv'' is the file version. Multiple versions of a meta-kernel for the data set may exist if new kernels were added to the archive in a later release and the meta-kernel had to be updated to incorporate them. The reasons for adding new kernels include (but are not limited to) adding new kinds of kernels, adding new versions of existing kernels containing more complete or more accurate data, and adding new versions of existing kernels superseding the existing kernels that had errors. If more than one meta-kernel file is present, then the file with the latest version number supersedes all earlier versions. Although the meta-kernels were created such that on a UNIX workstation they can be loaded into a SPICE-based application directly from the root directory of the data set -- because the PATH_VALUES keyword is set to './DATA' and '/' is used as the path delimiter -- it is recommended that users make local copies of these files and update the PATH_VALUES keyword in each of them to point to the actual location of the data set's 'data' directory on their system. Additional changes including replacing '/' and '\' in all path specifications and converting UNIX line terminator to terminators native to the user's system may be required to use these meta-kernels on non-UNIX workstation. The following guidelines were followed to pick and set priority -- determined by the order in which the kernel files are listed, with the latest one taking precedence -- for the kernel files included in these MKs (in the file name patterns below "?" represents one character): LSKs: - the latest archived generic LSK (NAIF????.TLS) SCLKs: - the latest archived VEX SCLK (VEX_??????_STEP.TSC) PCKs: - the latest archived generic PCK (PCK?????.TPC) - the DE 403 masses PCK (DE403_MASSES.TPC) - the latest archived high-precision Earth orientation binary PCK (EARTH_??????_??????_??????.BPC) FKs: - the EARTH_FIXED-to-ITRF93 mapping FK (EARTHFIXEDITRF93.TF) - the latest archived DSN station topocentric frames FK (EARTH_TOPO_??????.TF) - the latest archived ESA station topocentric frames FK (ESTRACK_V??.TF) - the latest archived ESA dynamic frames FK (RSSD????.TF) - the latest archived project FK (VEX_V??.TF) IKs: - the latest archived IK for each of the instruments (VEX_*_V??.TI) SPKs: - the DE405 planetary ephemeris SPK (DE405.BSP) - the latest archived outer planet centers SPK (OUTERPLANETS_V????.BSP) - the latest archived ITRF93 DSN station locations SPK (EARTHSTNS_ITRF93_??????.BSP) - the latest archived ESA station locations SPK (ESTRACK_V??.BSP) - the latest archived VEX orbiter complete mission SPK (ORVM_T19___________?????.BSP, lower priority) - the latest archived VEX spacecraft structures SPK (VEX_STRUCT_V??.BSP) CKs: - the latest archived VEX ASPERA orientation CK (VEX_ASPERA_SAF_051109_??.BC) - the latest archived VEX boom orientation CK (VEX_BOOM_V??.BC) - the latest archived VEX Solar Arrays orientation yearly CKs, multiple files to provide complete coverage (VEX_SA_????_V????.BC) - the latest archived VIRTIS orientation CKs, multiple files to provide complete coverage (VEX_VIRTIS_????_V??.BC) - the latest archived VEX predicted orientation CK (ATNV_T6_P051109051109_?????.BC, lower priority) - the latest archived VEX measured orientation CK, provided by the onboard AOCS system. The coverage is not continuous (ATNV_MEASURED_????_V??.BC) The following kernels were intentionally not included in the meta-kernels: EKs: - No EK files are included in the metakernel, its usage depends on the user (VEX_HGA_RAD_V??.BES). DSKs: - No DSK files were listed in MKs because SPICE Toolkits N0065 or earlier cannot load MKs with DSKs.