A Comparative Study of Bilinear Time–Frequency Transforms of ISAR Signals for Air Target Imaging

  • G. E. Boultadakis National Technical University of Athens
  • G. K. Kalognomos National Technical University of Athens
  • A. V. Karakasiliotis National Technical University of Athens
  • P. V. Frangos National Technical University of Athens
  • L. K. Stergioulas Brunel University


In this paper a comparative study of bilinear time-frequency (TF) transforms for Inverse Synthetic Aperture Radar (ISAR) imaging is presented. Following a concise presentation of the ISAR imaging method used in this work, as well as of the theory of the bilinear TF transforms involved in our numerical simulations, extended numerical results are presented for a reference simulated radar target and for various noise conditions. The constructed ISAR images are presented and analyzed quantitatively using an entropy cost function criterion, while corresponding run-time considerations have also been taken into account. As a result, it appears that the Smoothed Pseudo Wigner-Ville (SPWV) distribution provides us with images of superior quality. Furthermore, the analysis of the results demonstrates the usefulness of bilinear TF methods in ISAR imaging and showcases the relative performance advantages and disadvantages of the various distributions. Ill. 7, bibl. 22 (in English; summaries in English, Russian and Lithuanian).