Sea-Surface Specular Multipath for Surface-Level Antennas: Phase 1

Abstract

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. A. A. Beex Virginia TechApproved for public release; distribution is unlimited. SSC San DiegoSan Diego, CA 92152-5001 Executive SummaryThis document describes a specular multipath simulation for antennas located close to a sea surface. The antennas are circularly polarized but the ray-trace implementation readily accommodates any other polarizations. The transmitted signal s T (t) arrives at the receiver's antenna along the direct path and from multiple re°ections o® the sea surface. The surface-level antenna turns the multipath into multiplicative noise|assuming the receiver is narrow band. Under this narrow-band assumption, the received signal s R (t) is approximated by modulating the transmitted signal s T (t) with this multiplicative noise:The multiplicative noise fa(t)g is determined by the sea surface, the elevation angle of the transmitted signal path, and the receiver's antenna. By sweeping over various realizations of the sea surfaces, elevation angles, and various antenna heights and speeds, the systems engineer can estimate sea-surface specular multipath e®ects on the surface-to-satellite link.iii