Airborne 3-D forward looking SAR imaging via chirp scaling algorithm

Because of the influence of large range walk and geometrical distortion, traditional synthetic aperture radar (SAR) imaging algorithms, such as range doppler (RD) etc., cannot be used for three demensional (3-D) forward looking SAR (F-SAR) imaging directly. In this paper, we first derive the chirp scaling algorithm (CSA) for 3-D F-SAR. Next, we analyze the geometrical distortion analytically and provide an effective approach to reconstruct the scatters to their exact positions without interpolation. Moreover, we briefly discuss the point spread function´s isosurface shape and how geometrical distortion correction (GDC) influence on it. Finally, the simulation experiments about single point and multipoint verify the algorithm´s validity.