A Two-Dimensional Frequency Modulation Deception Jamming Against ISAR

This paper proposes a false target jamming method for countering ISAR based on two-dimensional frequency modulation. The target template is created according to the ISAR image of a true target. Then the range modulation signal, of which the frequency relates to each range cell of the template, is generated using direct digital synthesizer. The creation of modulation signal can be implemented parallel to accelerate the algorithm. All the range modulation signals are added up after amplitude adjustment and Doppler phase modulation. At last the jamming signal is derived from the multiplication between the intercepted radar signal and the modulation signal. Using the property of linear frequency modulated signal and frequency modulation, the jamming signal creates a false target of high fidelity after ISAR imaging. The proposed method is real-time when producing a false target with simple structure. For a template consists of a great many scatterers, the jamming algorithm is separated into real-time stage and off-line stage, which fulfills the generation of modulation signal after obtaining the radar parameters. The jamming effect on ISAR is presented through simulation results and the validity of the method is verified.