Abstract
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.
Highlights
Inverse synthetic aperture radar (ISAR) has the ability to provide two-dimensional (2-D) images of the observation target
According to (5), the range size of false target is contained in the frequency of modulation signal, which is based on the estimating value of chirp rate γ
Most of the proposed deception methods focus on the generation of multiple false targets based on the assumption that the jamming signal is reflected again by the real target or the jammer could receive the target echo, which is really a hard task in the real scene
Summary
Inverse synthetic aperture radar (ISAR) has the ability to provide two-dimensional (2-D) images of the observation target. Active frequency selective surface (AFSS) can dynamically switch its scattering intensity and impose amplitude modulation onto the radar signal [16] This method can be treated as the passive implementation of the interrupted-sampling repeater jamming, capable of generating 3-5 false targets along the range or azimuth direction. In terms of point A, the relative distance between origin o and A is approximately equal to yA, so the frequency of range modulation signal is: fm(A). We need modulate different Doppler frequencies onto the range modulation signal according to the azimuth location of each scatterer. The target echo is the superposition of radar signal reflected by each scatterer (in different range cells, different azimuth cells) in space. The time length of I (t, ta) is determined by the fast-time t, which is usually equal to the pulse width of radar signal
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
