UAS-borne CWSF SAR imaging: evaluation and compensation of Doppler effect

Radar sensors based on Unmanned Aerial Systems (UAS) poses new challenges in the field of data processing. The fine compensation of Doppler effect is one of this, especially for continuous wave step-frequency (CWSF) radar that typically operates at low pulse repetition frequency (PRF). In this paper the implications of Doppler effect on synthetic aperture radar (SAR) imaging are theoretically investigated and a specific focusing algorithm is proposed. Experimental data, acquired in a controlled but realistic scenario, validate the method.