Data Set Overview : This shape model of Phoebe is based on 208 Cassini Imaging Science Subsystem narrow and wide angle camera (ISSNA and ISSWA) images. The shape model was prepared by Robert Gaskell on July 7, 2010.  The geometrical coordinate system of this model is defined by the planetary constants file cpck13Sep2010.tpc (available in PDS from the NAIF node) with an updated pole from Thomas: RA:356.90 DEC:77.88 PM:178.58 W:939.639 (deg/da).  To find the file in PDS, go to the NAIF SPICE archive at http://naif.jpl.nasa.gov/naif/data_archived.html. In the table of data links, select the volume FTP link for the Cassini Orbiter mission. Within the volume, go to the data/pck directory, and download the desired file (cpck13Sep2010.tpc).  The parameters of the model are as follows:  Number of landmarks: 522 Formal position uncertainty: 150 m/component Number of images: 208 Pointing uncertainty: .032 mrad S/C position uncertainty: N/A (tight a prioris) Pointing residuals (relative to CK): 0.275 mrad Range residuals: N/A Number of measurement pairs 22555 Number of measurements per landmark: 131 RMS LMK location residual: 183 m/component   The models were originally prepared in the Implicitly Connected Quadrilateral (ICQ) format. Vertex-facet format versions, derived from the ICQ versions, are also provided. The filenames are phoebe_quad512q.tab and phoebe_ver512q.tab, where 512 is the value of Q (an indicator of the resolution). See below for the full definition of Q and the ICQ format.  The file 'phoebeimagelist.tab' is a list of the Cassini ISSNA and ISSWA images used to generate this model.  A text file, 'icqmodel.asc' is provided in the 'document' directory which describes the ICQ format and the derivation of the vertex-facet versions.

Confidence Level Overview : Note that the vertex-facet versions of the model have some duplicate vertices on the edges and corners of the cube. The duplicate vertices are not used in the facet table, resulting in the presence of some vertices in the vertex table which do not appear in the facet table. This does not affect the correctness of the vertex-facet version.