Title of Paper: Spaceborne Microwave Instrument for High
Resolution Remote Sensing of the Earth’s Surface Using a Large-Aperture Mesh
Antenna
Principal Author: Dr. Eni Njoku
Abstract: A study has been performed of a large-aperture,
lightweight, deployable mesh antenna concept for radiometer and radar remote
sensing of the Earth from space. The study focused on an instrument system to
measure ocean salinity and soil moisture. These measurements are not currently
available from space but are of critical importance in improving the knowledge
and prediction of key ocean and land surface processes. Deployable mesh
antennas are a new technology for remote sensing with potential applications in
many disciplines that require microwave observations at high spatial
resolution. Significant implementation challenges exist, however, that have
required careful study. The baseline concept described here features a rotating
6-m-diameter deployable-mesh antenna with radiometer and radar sensors to
measure microwave emission and backscatter from the Earth’s surface. The
sensors operate at L and S bands, with multiple polarizations and a constant
incidence angle, scanning across a wide swath. The key technology is the
low-mass, low-cost deployable mesh reflector antenna. This paper summarizes the
results of the system feasibility study, including the science requirements,
reflector and feedhorn design and performance, mesh microwave emissivity
measurements, lightweight radar electronics design, launch vehicle
accommodations, rotational dynamics, and attitude control issues associated
with the antenna and spacecraft. The goal of the study was to advance the
technology readiness of the instrument concept to a level appropriate for an
ESSP-class science mission.