Stardust: Shape Models of 81P/Wild 2 - Version 2

Status: Archived

This data set contains the shape models of comet 81P/Wild 2 as derived from the Stardust NAVCAM close approach images. There are two different models included:

1) a basic triaxial ellisoid that defines an envelope enclosing the entire surface observed by Stardust, and

2) the detailed topographic plate model that reproduces the surface features on the nucleus. Four versions of this model are included. The first two depict only the visible surface, in cartesian and planetocentric coordinates. The third and fourth depict the full surface, again in cartesian and planetocentric coordinates, with the non-visible portions represented by the best-fitting triaxial ellipsoid.

• ZIP file of the data set (1.8Mb, ~8Mb unzipped), for downloading.

An overview of the volume contents is provided in aareadme.txt.

Catalog Files

Catalog files contain the overview information and parameters used in loading the PDS central catalog, specifically, or for developing other interfaces to the data outside of PDS. The information they contain, particularly in their descriptive text fields, should be clear, complete, and understandable to a research user who is not necessarily an instrument specialist.

These files are located in the catalog/ subdirectory. The directory contents are described by the catinfo.txt file.

• Stardust Mission File
• Stardust spacecraft Catalog File
• Navcam Instrument Catalog File
• Data Set Catalog File
  
• 81P/Wild 2 Target Catalog File
• 5535 Annefrank Target Catalog File (Mentioned in Stardust catalog file)
• Reference list

Documentation Files

In addition to the small text files located throughout the volume to describe directory contents, there are specific documents provided to assist with understanding the data involved. The files are located in the document/ subdirectory. The directory contents are described by the docinfo.txt file.

• A short description of the triaxial ellipsoid model and how it was developed is given in the model_desc.txt document, which contains two figures.
  • Document model_desc.txt.
  • Label model_desc.lbl
  • figure1.png (PNG format) or figure1.pdf (PDF format)
  • figure2.png (PNG format) or figure2.pdf (PDF format)

• A description of the detailed plate model and how it was created is given in the plate_model_desc.txt document, which contains one figure.
  • Document plate_model_desc.txt.
  • Label plate_model_desc.lbl
  • plate_figure1.png (PNG format) or plate_figure1.pdf (PDF format)

• A description of the steps taken at the SBN to prepare the Wild 2 shape model for inclusion in the PDS.
  • Document model_prep.txt.
  • Label model_prep.lbl

Data Files

The data files are located in the data/ subdirectory. The PDS labels are in separate files from the data.

• wild2_shape.tab lists the basic triaxial ellipsoid shape model parameters.
  Label is wild2_shape.lbl

• wild2_cart_vis.tab contains the plate model of the visible portions of the nucleus in cartesian coordinates.
  Label is wild2_cart_vis.lbl

• wild2_plan_vis.tab contains the plate model of the visible portions of the nucleus in planetocentric coordinates.
  Label is wild2_plan_vis.lbl

• wild2_cart_full.tab contains the plate model of the full surface of the nucleus in cartesian coordinates (non-visible portions are represented by the best-fitting ellipsoid).
  Label is wild2_cart_full.lbl

• wild2_plan_full.tab contains the plate model of the full surface of the nucleus in planetocentric coordinates (non-visible portions are represented by the best-fitting ellipsoid).
  Label is wild2_plan_full.lbl

Browse Files

The browse/ subdirectory contains two VRML versions of the shape model. These can be viewed and manipulated with any standard VRML viewer. The model depicted in these files is the full version, with a triaxial ellipsoid used to fill in for parts of the surface that were not derived. The directory contents are described by the browseinfo.txt file.

The first version, wild2_shape_vrml_solar.wrl uses illumination conditions that approximate those at the time of encounter (PDS label)

The second version, wild2_shape_vrml_headl.wrl uses a headlight to fully illuminate the detailed structure. (PDS label)

Index Files

This directory contains an index into the data files included on this volume (in the data/ directory).

• indxinfo.txt describes the directory contents.
• index.lbl describes the contents of the index.tab file.