X-SAR specification, design, and performance modeling

The detailed design and development phase of the X-SAR 9.6-GHz vertical polarization segment of the Shuttle Radar Lab (SRL) mission, started in Spring 1987, is discussed. The design incorporates a planar array antenna based on metallized carbon-fiber-reinforced plastic technology, a traveling-wave-tube amplifier, and a dual-channel receiver using surface acoustic wave devices. Several radar parameters are controllable from ground to achieve high performance over a wide range of measurement geometries. Definitions of image performance parameters and modeling algorithms developed in support of instrument specification and performance monitoring during hardware development are presented. The algorithms have been implemented as a software tool to perform sensitivity analysis and generate interesting graphical results to support top-level instrument verification