An analysis of ISAR image distortions in multistatic passive radars for air surveillance

The paper presents an analysis of radar image distortions caused by using the Polar Formation Algorithm (PFA) for Inverse Synthetic Aperture Radar (ISAR) image creation in multistatic passive radar. The Passive ISAR technology is still in the development stage, and many challenges and limitations have to be overcome before it would be applied in the commercial operating passive coherent location (PCL) systems. One of such limitations is an image distortion caused by applying the simplified processing techniques for creating ISAR images. This particular topic is discussed in detail in this paper. A theoretical analysis verified by processing of simulated data is shown as well as results of both the ISAR image formation and the image distortions in multistatic passive radars are presented for different multistatic geometries. Finally, the authors discuss possible directions of further research in passive radar imaging utilizing the multistatic geometry.