Wide-band multi-look passive ISAR

Abstract

This chapter discusses the passive inverse synthetic aperture radar (SAR) (ISAR) (P-ISAR) technique. Radar imaging, and in particular P-ISAR, is a new feature for passive radars (PRs) made possible by the recent technological advances. This chapter presents the theory of the P-ISAR algorithm. It also discusses the issues related to the application of the ISAR technique to passive coherent location (PCL) systems and in particular the obtainable spatial resolutions. How to deal with this problem is also discussed in this chapter. Finally, results on real data from two different PCL systems are presented to demonstrate the feasibility and effectiveness of P-ISAR. This chapter is organized as follows. Section 4.1 introduces the P-ISAR concepts and its main 'ingredients'. Section 4.2 deals with the data preprocessing that includes all the steps necessary to obtain data suitable for the application of ISAR technique. Section 4.3 presents the ISAR image processing algorithm. It also proposes a method for handling incomplete data, particularly data with frequency ranges, that occurs when a full bandwidth signal is not available. Section 4.4 presents the results obtained by processing two datasets gathered with two different PCL systems. Main conclusions are finally drawn in Section 4.5.