Large deployable-mesh antenna system for ocean salinity and soil moisture sensing

A concept has been studied for remote sensing of sea surface salinity and soil moisture from space using a large deployable mesh antenna system. The antenna has a 6-m-diameter offset-fed parabolic reflector with multichannel feedhorns operating at L and S bands. The antenna boresight is offset from nadir and the entire system rotates about the nadir axis, providing a conical scan with high-precision measurements across a wide swath at a spatial resolution of about 40 km from a 600-km orbit altitude. The study includes evaluation of deployable mesh antennas and preferred antenna, spacecraft, and launch vehicle configurations. Designs for compact, lightweight feedhorns and radiometer/radar electronics are being developed and evaluated. Laboratory measurements of the emissivity of mesh samples under simulated orbital conditions are being made to evaluate the suitability of current mesh designs for high-precision radiometric applications