High-resolution shape model of Ceres from stereophotoclinometry using Dawn Imaging Data

We present a high-resolution global shape model of Ceres determined using the stereophotoclinometry technique developed at the Jet Propulsion Laboratory by processing Dawn's Framing Camera data acquired during Approach to post-Low Altitude Mapping Orbit (LAMO) phases of the mission. A total of about 38,000 images were processed with pixel resolutions ranging from 35.6 km/pixel to 35 m/pixel and the final global shape model was produced with 100-m grid spacing. The final SPC-derived topography was computed relative to the (482 km, 482 km, 446 km) mean ellipsoid, which ranges from -7.3 km to 9.5 km. For the purpose of validation, we performed various error analyses to assess and quantify realistic uncertainties in the derived topography, such as dividing the data into different subsets and re-computing the entire topography. Based on these studies, we show that the average total height error of the final global topography model is 10.2 m and 88.9% of the surface has the total height error below 20 m. We also provide improved estimates of several physical parameters of Ceres. The resulting GM estimate is (62.62905 +/- 0.00035) km(3)/s(2), or the mass value of (938.392 +/- 0.005) x 10(18) kg. The volume estimate is (434.13 +/- 0.50) x 10(6) km(3) with a volumetric mean radius of 469.72 km. Combined with the mass estimate, the resulting bulk density is (2161.6 +/- 2.5) kg/m(3). Other improved parameters include the pole right ascension, alpha(o) = (291.42763 +/- 0.0002)degrees , pole declination, delta(0) = (66.76033 +/- 0.0002)degrees, and prime meridian and rotation rate of (W-0 = 170.309 +/- 0.011)degrees and (dW/dt = 952.1532635 +/- 0.000002) deg/day, respectively. Also, for geophysical and geological studies, we provide spherical harmonic coefficients and a gravitational slope map derived from the global shape model.