Combining a subaperture and chirp scaling approach for real-time SAR processing

This paper presents an efficient approach for realtime SAR processing which consists basically of a combination of the chirp scaling algorithm and a subaperture algorithm. The proposed approach, which is denoted as extended chirp scaling (ECS), combines the accuracy of the chirp scaling with the flexibility of the subaperture processing for the update of the Doppler parameters. In addition, the memory requirements are reduced by the use of subaperture processing and the variations of the Doppler centroid in range and azimuth are accurately incorporated by the extended chirp scaling approach, The paper presents also some preliminary results obtained by the real-time SAR processor for the airborne SAR system of DLR.