Research On Jamming Theory And Effective Jamming Method To High Resolution SAR

As an important military reconnaissance means, high-resolution synthetic aperture radar (SAR) plays an increasingly prominent role in modern wars. Therefore, the research on high-resolution SAR jamming has become an important topic in the field of military electronic countermeasure.Though lots of SAR jamming methods have been proposed, none of them is based on the characteristics of high-resolution SAR. What's more, they all lack of theoretical innovations. Supported by the National "973" Project, researches are conducted in this dissertation as follows:1. Research on the jamming theory of high-resolution SAR based on the similarityies of signal characteristicsThe difficulties of high-resolution SAR jamming are revealed, based on the analysis on the high-resolution SAR system, and followed by researches on the scattering mechanism, echo model and RCS statistical characteristics of high-resolution SAR in detail. The similarity measurement is defined, and a new SAR jamming theory is proposed based on the similarity characteristics of SAR echoes.2. Analysis on the conventional SAR jamming methodsThe deficiencies of conventional methods are pointed out, through the analysis on conventional SAR jamming. Lacking of the similarities of SAR signals, high jamming power is needed in power jamming, so effective jamming is difficult to achieve. While cheating jamming is difficult to realize for its intolerably perplex structure and high precision of the system parameters.3. Research on anti-jamming methods based on signal differenceAccording to the similarity measurement of the conventional SAR jamming methods , the anti-jamming theory based on signal characteristics difference is proposed. On this basis, the author researches several anti-jamming methods and proposes a new technique to separate noise jamming signals based on the Independent Component Analysis (ICA) technique. And the author finds out that using the differences between the jamming signal and the high-resolution SAR echo in the multidimensional characteristics, signal forms and scattering statistical characteristics respectively, the jamming signal can be suppressed or removed.4. Research on a new jamming method—Similar Clutter Jamming Method A new jamming method - Similar Clutter Jamming Method (SCJM) - is presentedbased on the similarity theory of signal characteristic. The characteristic of jamming signal generated by this method is similar to that of high-resolution SAR echoes in the multidimensional spaces. Compared with other methods, SCJM has simpler structure using multidimensional modulation techniques. The experimental results indicate that this new method can be utilized in the high-resolution SAR processing gain and reduce the jamming energy greatly. Compared with cheat jamming, it can reduce the requirement for the estimation precision of the SAR system parameters, so it is easier to realize.5. Research on the wideband jamming signal generation technologyTwo wideband jamming signal generation techniques are researched in this dissertation. One is the baseband jamming signal modulation technique using the anti-deslope local frequency source to generate wideband jamming signal. The other uses narrowband signals to synthesize wideband jamming signal. The results and conclusions of the wideband jamming signal generation technique have been applied in the realization of high-resolution SAR jamming system.