STANFORD UNIVERSITY
EE 350 RADIOSCIENCE SEMINAR
Professor Antony Fraser-Smith

Fall 2000-2001

Date: Wednesday, April 25, 2001
Time: 4:15-5:30 PM; Refreshments at 4:00 PM
Location: Bldg. 200, Rm. 34


Fresnel Reflectivity and its Application to Planetary Exploration

Dr. Richard Simpson
Space, Telecommunications, and Radioscience Laboratory, Stanford University

Abstract

Fresnel reflectivity is typically introduced in electromagnetics classes shortly after wave propagation. In its simplest form, it relates material properties and geometry to measured power reflected from an interface. . Investigations of Fresnel reflectivity are ideally suited to bistatic radar exploration of planetary surfaces where geometries other than backscatter are the norm.Fresnel principles were used to determine the dielectric constant of the lunar crust through detection of the Brewster angle in the 1960's with Explorer 35. More recently they have been used to infer a thin semiconducting coating on high peaks of Venus, where elemental tellurium provides a good match to measured material properties. In the past year, bistatic probing has been used to study the surface properties of Mars near where the Mars Polar Lander and Deep Space 2 probes mysteriously disappeared a year and a half ago. We will review past accomplishments using Fresnel techniques in planetary exploration, discuss some of the limitations, and look ahead to future opportunities.