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.