Filling out the SPICE Kernel Files Class

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The SPICE_Kernel_Files class is used to cite the specific SPICE kernel files used in calculating the associated geometry. Since SPICE kernels are also archivable products, they will usually be referenced by their PDS logical identifier and version ID by the time (i.e., LIDVID) by the time the associated data are archived. If referencing by LIDVID presents a problem, you should let PDS node consultant know ASAP, and use the various names and IDs that are included optionally in this class to help link early mission data to its final SPICE kernels after the fact.

<SPICE_Kernel_Identification>

REQUIRED

You are required to identify at least one SPICE kernel in your <SPICE_Kernel_Files> class. You will repeat this class for each kernel file you need to reference.

Note that if you reference a meta-kernel, you do not need to reference all the kernel files that the meta-kernel references. Make sure you include the appropriate version ID in the kernel reference, though.

<kernel_type>

REQUIRED

This is the standard NAIF/SPICE abbreviation used to identify kernels in that toolkit. It must have one of the following values:

  • CK
  • DBK
  • DSK
  • EK
  • FK
  • IK
  • LSK
  • MK
  • PCK
  • SCLK
  • SPK

<file_name>

OPTIONAL


<frame_spice_id>

OPTIONAL

<frame_spice_name>

OPTIONAL

<body_spice_id>

OPTIONAL

<body_spice_name>

OPTIONAL

<local_spice_kernel_name>

OPTIONAL

<Internal_Reference>

OPTIONAL

The preferred method for referencing your SPICE kernels is by their PDS URI (LIDVID, in particular), because this allows the kernels to be programmatically linked to this data product.

Note, however, that the elements in this class are considered to be in the PDS4 core namespace, not the geometry dictionary namespace. So you will need to provide the PDS4 core namespace reference when using the elements. There are two ways to do that: by using a pre-defined namespace prefix, or by specifying the PDS4 core namespace URI via an xmlns XML-attribute in each of the tags. For this page, we're using the namespace abbreviation as a prefix on the tag.

If that all sounds like gibberish to you, you might want to check the Namespace Reference topic on the "Schema Referencing" page on this wiki.

<pds:lid_reference> or <pds:livid_reference>

REQUIRED

One or the other of these is required to be present. In most cases, version matters and you should reference your SPICE kernel products by LIDVID rather than just LID.

<pds:reference_type>

REQUIRED

This must have a value of geometry_to_spice_kernel.

<pds:comment>

OPTIONAL

If you have anything else you'd like to say about the particular kernel product being referenced, here would be the place to do it.

<comment>

OPTIONAL

If you have any additional comments to make about the SPICE kernels you've referenced, this is the place to do it.