SPICE Data Catalog

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A “SPICE data” catalog file specifies all the SPICE kernels that need to be loaded to run a visualization for a particular mission. This is an example of a SPICE data catalog file listing  CASSINI SPICE data:

{
   "version": "1.0",
   "name": "Cosmographia CASSINI Example",
   "spiceKernels": [
      "kernels/cas_1997_v15.tm",
      "kernels/cas_1998_v15.tm",
      "kernels/cas_1999_v15.tm",
      "kernels/cas_2000_v17.tm",
      "kernels/cas_2001_v18.tm",
      "kernels/cas_2002_v17.tm",
      "kernels/cas_2003_v17.tm",
      "kernels/cas_2004_v17.tm",
      "kernels/cas_2005_v18.tm",
      "kernels/cas_2006_v17.tm",
      "kernels/cas_2007_v15.tm",
      "kernels/cas_2008_v13.tm",
      "kernels/cas_2009_v10.tm",
      "kernels/cas_2010_v09.tm",
      "kernels/cas_2011_v08.tm",
      "kernels/cas_2012_v05.tm",
      "kernels/cas_2013_v02.tm"
   ]
}
Note that SPICE data catalogs can load SPICE meta-kernels, as shown in this example, as well as individual SPICE kernels.
The version and name attributes are set to the current version of Cosmographia and the internal name of the catalog file.
The spiceKernels attribute lists the names of the SPICE kernels and/or meta-kernels to be used for the mission of interest. The total number of SPICE kernels is limited only by SPICE capabilities. Loading a large number of SPICE kernels (hundreds or thousands) lengthens loading time but normally does not affect visualization speed. Note the following:
  • Use and maintenance of this kind of catalog file tends to be easier with the use of SPICE meta-kernels rather than individual SPICE files.
  • Multiple kernel/meta-kernel names in the list must be separated by commas (this follows the catalog convention for an array).
  • Individual kernels and meta-kernels provided in the list must be loadable from the directory in which the catalog file resides. For meta-kernels this means that kernels included in them must use correct relative and/or absolute paths.
  • When using SPICE data from the PDS’ NAIF Node archive, multiple meta-kernel versions for a mission, or for each year of a mission, may exist. In this case, use only the latest version meta-kernel for the mission or for a given year.
A more detailed description of some of the parameters in this catalog file is provided in the “CATALOG FILE SETTING UP USE OF SPICE DATA” section of the Cosmographia-SPICE User’s Guide.