Extended range migration algorithm for squinted spotlight SAR

Several algorithms are available for SAR data processing and it has been shown that they lead to acceptable results in standard situations. However, processing of SAR data is a very difficult task if high resolution is to be achieved in spotlight mode with a large squint angle. In this case the echoes of a scene span a wide range area and the storage in a rectangular data field is inefficient. This paper presents an extended range migration algorithm which solves the problem by an adaptation of the receiver range gate. Then, the signal can be described in modified range and wave number components leading to a reduction of the memory requirement. Because of the limitation of the processed data to the scene echoes the processing efficiency increases. Beside the theoretical presentation of the new method the applicability is shown using simulated data.