A modified imaging formation algorithm for bistatic SAR based on GPS-L5 signal

Comparing with the traditional global navigation satellite system (GNSS) based Bistatic SAR (GNSS-based BiSAR), the BiSAR based on GPS-L5 signal plays a superior role in remote sensing applications, as for its feature of stronger power and larger bandwidth. In applying this method, the consequent problems, yet, such as long dwell time and large range cell migration (RCM) are inevitably leading the traditional image processing algorithm non-applicable. Therefore, a refined imaging formation algorithm for this BiSAR data imagery was proposed. Firstly, a modified bulk RCM correction (RCMC) was presented based on a fifth-order two-dimensional point target spectrum. After bulk RCMC processing, the phase resulted from RCM and range-azimuth coupling at the reference range was removed. Then, as the bulk RCMC dramatically changed the echo's range history, a refined hybrid correlation operation emerged to compensate the residual phase errors. Finally, the simulation and imaging results measures the validity and accuracy of the proposed method.