This project will enable more efficient use of a scarce resource, the radio spectrum. This project will have broad impact on the public by enabling increased efficiency in communications between citizens, while simultaneously shared use of the same frequency range for radar applications. The techniques developed will potentially reduce the impact by both accidental and intentional (jamming) interference. Students, who will carry out part of the research, will be better trained to join the US work force. Furthermore, their use of the research in the classroom presentations will lead to a keener appreciation of the use and issues faced by permitting widespread use of cognitive radio devices, devices that can change its wireless channel at will.This proposal explores the potential for Synthetic Aperture Radars to operate with other users of the spectrum. In particular it aims to explore the capacity for a Radar system to operate efficiently by recognizing and discarding false positive signals; in effect by using a variety schemes to identify and ignore interference. Their approach is unique in that it attempts to integrate the spectrum sharing into the fundamental operation of the radar.