Study on the System Design Scheme for Wide-Swath Spaceborne SAR Operating in the Frequency-Scanning Mode

Utilizing the frequency-dependent beam pointing characteristics of phased array antenna, frequency scanning (F-SCAN) spaceborne SAR can realize the smooth beam scanning from the far to the near edge of the observation scene. This property could enhance the wide-swath imaging performance in terms of signal-to-noise ratio (SNR) and side lobe suppression. Besides, it can achieve the constant and high image quality independent of target position within the scene. In this paper, we make a thorough investigation into this novel operation mode and present the overall and detailed system design procedure. In addition, the system performance evaluation approach is also given and its differences from that of conventional spaceborne SAR are emphasized. At last, an exemplary spaceborne SAR system operating in F-SCAN mode is brought forward and corresponding simulation results validate the effectiveness of our system design scheme as well as advantages of F-SCAN SAR.