Modeling the martian surface using bistatic radar at high incidence angles

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Abstract/Contents

Abstract
A bistatic radar system uses a transmitter and receiver in two separate locations to measure electromagnetic wave reflections at a distance. Such systems have been used since the 1960s to probe planetary surfaces, yielding information on their physical and electrical properties. Here we report the first successful uplink-geometry planetary bistatic radar observations. In 2005, the planet Mars was illuminated 56 times for 20 minutes each by an unmodulated 75-cm wavelength circularly polarized wave transmitted from the SRI International 46-m antenna in the Stanford foothills. The direct signal and a Martian surface echo, separated by differential Doppler frequency shifts, were received simultaneously by the one-bit receiver on board the Mars Odyssey orbiter. The surface echoes exhibit both fluctuating amplitude and varying spectral width, which are responses to surface reflectivity and roughness variations along the surface track. We analyze the echo data using quasi-specular scattering theory and exploit high-resolution Mars Orbiter Laser Altimeter topographic maps to better model the scattering surface in three dimensions at positions along the specular track of the echo. Assuming a two-scale classical scattering model, we infer surface roughness in the form of rms surface slopes. The results are important for evaluating landing safety for Mars exploration spacecraft, because the radar is sensitive to slopes on the order of a wavelength in size and larger. Most recently our results were used by NASA for the 2007 Phoenix Mars Lander landing site selection.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Copyright date 2010
Publication date 2009, c2010; 2009
Issuance monographic
Language English

Creators/Contributors

Associated with Gunnarsdottir, Hrefna Marin
Associated with Stanford University, Department of Electrical Engineering.
Primary advisor Linscott, Ivan
Primary advisor Zebker, Howard A
Thesis advisor Linscott, Ivan
Thesis advisor Zebker, Howard A
Thesis advisor Fraser-Smith, A. C. (Antony C.)
Advisor Fraser-Smith, A. C. (Antony C.)

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Hrefna Marin Gunnarsdottir.
Note Submitted to the Department of Electrical Engineering.
Thesis Thesis (Ph.D.)--Stanford University, 2010.
Location electronic resource

Access conditions

Copyright
© 2010 by Hrefna Marin Gunnarsdottir
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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