Planetary Radar 757
FIGURE 18 Mars Landersites and estimates of 3.5-cm rms slope and circular polarization ratio. The width
across the front of the image is about 3 m in the right column and about 2 m in the left column. (NASA/JPL,
courtesy of A. F. Haldemann.)and 8.3 mHz (0.15 mm s−^1 in radial velocity), placing thou-
sands of pixels on the asteroid. This data set provided phys-
ical and dynamical information that was unprecedented
for an Earth-crossing object. Extraction of the information
in this imaging data set required inversion with a much
more comprehensive physical model than in the analysis
of Castalia images; free parameters included the asteroid’s
shape and inertia matrix, initial conditions for the asteroid’s
spin and orientation, the radar scattering properties of the
surface, and the delay–Doppler trajectory of the center of
mass (see Fig. 19).
Toutatis has complex linear features as well as circu-
lar crater-like structures down to the several-decameter
resolution limit. The features suggest a complex interior