Paired echo suppression algorithm in helicopter‐borne SAR imaging

A helicopter may vibrate at high frequencies during its flight, which can give rise to paired echoes in the helicopter‐borne synthetic aperture radar (SAR) imagery. This phenomenon substantially degrades the quality of SAR images since it may generate unwanted ghost targets in the images. In this study, the authors propose a method consisting of three steps to suppress paired echoes in helicopter‐borne SAR imagery based on the characteristics of the helicopter vibration. The proposed method can suppress paired echoes with high efficiency and accuracy in the case of vibrations with varying amplitude. Furthermore, this method does not require the presence of isolated or strong points in a range cell. Both simulated and acquired data are processed to demonstrate the effectiveness of the proposed algorithm.