Analysis of two different implementations of the SPECAN algorithm for real-time range compression of SAR data

Two implementation methods of the range compression via the SPECAN approach are presented. The first method is the column exploitation method and uses only one deramping function for the signal demodulation. The look arrangement exploits the calculated data in frequency domain best possible by using the transformed values for different looks. The look number is determined by the system parameters and thus computed automatically. The second method is the multiple deramping method. In this method, the lengths of the reference functions used for deramping result from the required geometric resolution, while the look number is an input value chosen by the user. Both methods are compared in terms of impulse response function, geometric resolution, radiometric resolution and computational effort. An analysis of the results illustrates the possibilities and limits of the methods. This work has been done under ESA/ESTEC contract No. 12958/98/NL/PA in conjunction with Dornier Satellitensysteme, Ottobrunn.