Data Set Overview :  This shape model of Tethys is based on 814 Cassini ISSNA and 6 Cassini ISSWA images taken in the years 2004-2010.  Coordinate system:  BODY603_POLE_RA : ( 40.66 -0.036 0. ) BODY603_POLE_DEC : ( +83.52 -0.004 0. ) BODY603_PM : ( 10.45 +190.6979085 0. ) BODY603_LONG_AXIS : ( 0. ) BODY603_NUT_PREC_RA : ( 0. 0. 0. +9.66 0. 0. 0. 0. 0. ) BODY603_NUT_PREC_DEC : ( 0. 0. 0. -1.09 0. 0. 0. 0. 0. ) BODY603_NUT_PREC_PM : ( 0. 0. 0. -9.60 +2.23 0. 0. 0. 0. )  (For help in interpreting the values of the SPICE assignments above, see the document 'PCK Required Reading' (PCK.REQ), available at NAIF and in the document directory of this data set.)  The parameters of the model are as follows:  Number of landmarks: 2457 RMS position uncertainty: 313 m/dof (degree of freedom) Pointing uncertainty: .431 mrad Pointing residual: .211 mrad Number of observations: 150361 Observations per landmark: 61.2 RMS landmark location residual: 618 m/dof  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 tethys_quad512q.tab and tethys_ver512q.tab, where 512 is the value of Q (an indicator of the resolution). Files with three selections of lower resolution are also provided for each format, with similar filenames but lower values of q.  The file 'tethysimagelist.tab' is a list of the Cassini ISSNA and ISSWA images used to generate this model. These images are archived in PDS under the data set ID CO-S-ISSNA/ISSWA-2-EDR-V1.0.  A text file, 'icqmodel.asc' is provided in the 'document' directory which describes the ICQ format and the derivation of the vertex-facet versions. For additional information about the shape models, see Gaskell et al. (2008).  References :  Gaskell, R.W., O.S. Barnouin-Jha, D.J. Scheeres, A.S. Konopliv, T. Mukai, S. Abe, J. Saito, M. Ishiguro, T. Kubota, T. Hashimoto, J. Kawaguchi, M. Yoshikawa, K. Shirakawa, T. Kominato, N. Hirata, and H. Demura, Characterizing and navigating small bodies with imaging data, Meteoritics and Planetary Science, vol. 43, Issue 6, p. 1049-1061, 2008.

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.