Concept of an X-Band Synthetic Aperture Radar for Earth-Observing Satellites

This paper presents a technical concept for an X-band phased array synthetic aperture radar mounted on a polar orbiting satellite. The interdependency of various parameters, such as geometric resolution, swath width and off-nadir angle, is shown as well as their influence on the sensitivity of the system. A description is given of the layout of the phased array system with a new dual polarized slotted waveguide array and attached GaAs transmit/receive modules. The antenna pattern is investigated for specified scanning ranges in elevation and azimuth direction. Descriptions are given of a possible high resolution mode (azimuth look steering mode) and a survey mode (scan SAR). Future SAR systems require a high stability in their system parameters or, at least, the possibility of calibrating their performance in an operational mode. External and internal radiometric calibration procedures are discussed. A method which monitors 64 sub-arrays and can be relatively easily implemented is suggested for internal c...