Publication Abstracts

Stiles et al. 2008

Stiles, B.W., R.L. Kirk, R.D. Lorenz, S. Hensley, E. Lee, S.J. Ostro, M.D. Allison, P.S. Callahan, Y. Gim, L. Iess, P. Perci del Marmo, G. Hamilton, W.T.K. Johnson, R.D. West, and Cassini RADAR Team, 2008: Determining Titan's spin state from Cassini RADAR images. Astron. J., 135, 1669-1680, doi:10.1088/0004-6256/135/5/1669.

For some 19 areas of Titan's surface, the Cassini RADAR instrument has obtained synthetic aperture radar (SAR) images during two different flybys. The time interval between flybys varies from several weeks to two years. We have used the apparent misregistration (by 10-30 km) of features between separate flybys to construct a refined model of Titan's spin state, estimating six parameters: north pole right ascension and declination, spin rate, and these quantities' first time derivatives We determine a pole location with right ascension of 39.48 degrees and declination of 83.43 degrees corresponding to a 0.3 degree obliquity. We determine the spin rate to be 22.5781 deg/day or 0.001 deg/day faster than the synchronous spin rate. Our estimated corrections to the pole and spin rate exceed their corresponding standard errors by factors of 80 and 8, respectively. We also found that the rate of change in the pole right ascension is -30 deg/century, ten times faster than right ascension rate of change for the orbit normal. The spin rate is increasing at a rate of 0.05 deg/day per century. We observed no significant change in pole declination over the period for which we have data. Applying our pole correction reduces the feature misregistration from tens of km to 3 km. Applying the spin rate and derivative corrections further reduces the misregistration to 1.2 km.

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BibTeX Citation

@article{st03710v,
  author={Stiles, B. W. and Kirk, R. L. and Lorenz, R. D. and Hensley, S. and Lee, E. and Ostro, S. J. and Allison, M. D. and Callahan, P. S. and Gim, Y. and Iess, L. and Perci del Marmo, P. and Hamilton, G. and Johnson, W. T. K. and West, R. D. and Cassini RADAR Team},
  title={Determining Titan's spin state from Cassini RADAR images},
  year={2008},
  journal={Astronomical Journal},
  volume={135},
  pages={1669--1680},
  doi={10.1088/0004-6256/135/5/1669},
}

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RIS Citation

TY  - JOUR
ID  - st03710v
AU  - Stiles, B. W.
AU  - Kirk, R. L.
AU  - Lorenz, R. D.
AU  - Hensley, S.
AU  - Lee, E.
AU  - Ostro, S. J.
AU  - Allison, M. D.
AU  - Callahan, P. S.
AU  - Gim, Y.
AU  - Iess, L.
AU  - Perci del Marmo, P.
AU  - Hamilton, G.
AU  - Johnson, W. T. K.
AU  - West, R. D.
AU  - Cassini RADAR Team
PY  - 2008
TI  - Determining Titan's spin state from Cassini RADAR images
JA  - Astron. J.
JO  - Astronomical Journal
VL  - 135
SP  - 1669
EP  - 1680
DO  - 10.1088/0004-6256/135/5/1669
ER  -

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