Research Of Jamming On Pulse Compression Radar Based On Chaos

Radar is a key weapon in modern warfare. The performance stability of radar, especially under complex electromagnetic circumstances, will directly determine the results of warfare. In order to blind the enemy's radar and to protect the strategic facilities of our own, various approaches are required to interfere with the enemy's radar. Therefore, research on radar jamming is of importance in practice.With the increasing development of science and technology, more and more new radar systems emerge. This brings lots of troubles to radar jamming, so radar jamming needs new idea, new theory and new technology urgently. Fortunately, as a new branch of nonlinear science, chaos theory has attracted considerable attention in the world. Particularly, new explorations applying chaos theory in the radar systems are being developed, which originates from the finding of chaotic property of sea clutter. The achieved results show that there has a widely application prospect for chaos in the field of radar electronic countermeasure.This thesis focuses on radar jamming technology based on chaos. Two typical pulse compression radar systems, linear frequency modulation radar (LFM) and binary phase-coded radar (BC), are taken into account. The detailed contents of this thesis are listed in the following:At first of all, the basic principles and signal characteristics of LFM and BC have been analyzed, and the models of radar receiver have been established. The process of realizing pulse compression in LFM and BC has been introduced in detail. Then corresponding simulations have been carried out in computer.Secondly, the cheating jamming of LFM based on chaos has been investigated. It is difficult to jam LFM by noise. However, the signal of LFM has a strong coupling between frequency and time, which makes LFM can be jammed by shift-frequency jamming easily. On the basis of sensitivity to initial value and pseudo-random characteristics of chaos, chaotic shift-frequency jamming on LFM is studied, including chaotic velocity gate pull off jamming, chaotic Doppler-frequency-blinking jamming and chaotic false Doppler-frequency jamming. On the basis of characteristics of chaos and the principles of radar range cheating jamming, the method of chaotic pulse position modulation jamming on LFM is studied, includingchaotic pulse position modulation range gate pull off jamming and chaotic pulse position modulation range false target jamming. Each kind of principle of jamming method is expatiated respectively. Computer simulation experiments have been carried out to verify the jamming effect.Thirdly, the jamming technology of BC based on chaos has also been studied. Similar to LFM, BC has a strong power to resist noise jamming. On the basis of sensitivity to initial value and pseudo-random characteristics of chaos, chaotic pulse phase modulation jamming and chaotic pulse position modulation range cheating jamming are investigated. The principles of jamming, computer simulations and the associated jamming effect have been shown orderly.In conclusion, the research results indicate that it is feasible to use chaos to jam LFM and BC, moreover, the jamming effect is fairly well.