NASA's L-Band Imaging Scatterometer

摘要

The NASA RADSTAR instrument is a compact scatterometer-radiometer system designed for airborne and space remote sensing of Earth surface properties such as soil moisture and sea surface salinity. In this paper we describe the active portion of RADSTAR, the L-band Imaging Scatterometer (LIS). The system employs electronic steering and digital beamforming techniques to generate multiple, low-sidelobe beams over a scan range of +/-50 degrees below an aircraft. We discuss the design and testing of LIS, and the planned merging of the scatterometer with the radiometric components of the final instrument. In its final configuration, RadSTAR will employ a single broadband antenna to efficiently support simultaneous scatterometer (LIS) and radiometer measurements in airborne and spaceborne applications. LIS is currently being flown along with the ESTAR synthetic aperture radiometer aboard the NASA P-3 aircraft in order to prove the concept of coregistered data, setting the path for future spaceborne, single aperture, electronically scanned, radar/radiometer systems.