HR: 0800h
AN: P41B-0941    [Abstracts]
TI: Modeling Backscatter From the Venusian Surface Using Composite Scattering Laws, and Their Equivalent Fractal-Based Representations
AU: * Sultan Salem, A K
EM: salatino@stanford.edu
AF: Stanford University, 350 Serra Mall Packard Electrical Engineering, Stanford, CA 94305
AU: Tyler, L
EM: len.tyler@stanford.edu
AF: Stanford University, 350 Serra Mall Packard Electrical Engineering, Stanford, CA 94305
AB: As is evident from processing Magellan altimeter backscatter data, quasi-specular scattering from some locations on the surface of Venus exhibits a sharp increase in magnitude at near-zero angles. Modeling the radar cross section observations by use of a single scattering law, such as the Hagfors, Gaussian, and exponential laws, does not capture this scattering behavior. On the other hand, a linear superposition of scattering laws, such as Gaussian plus Gaussian or Gaussian plus exponential, enables accurate modeling of the surface scattering observations. Such composite scattering laws, from the geometric-optics point of view, imply that the distribution of slopes within the radar resolution cells is a superposition of a number of distributions having the same functional form as the corresponding scattering laws. This may reflect, for example, the effects of the different geophysical processes shaping the surface. The use of the classical or standard laws gives some insight into surface condition by providing a measure of the root-mean square (RMS) slope, but fails to connect slope with horizontal scale. An equivalent fractal-based interpretation, applicable to both individual and linear superposition of scattering laws, has the advantage of producing scale-explicit RMS slope estimates. That is, the inferred RMS slope is a function of the horizontal scale on which the RMS slope is estimated and the electromagnetic wavelength used to probe the surface.
DE: 5464 Remote sensing
DE: 5470 Surface materials and properties
DE: 6295 Venus
SC: Planetary Sciences [P]
MN: Fall Meeting 2005