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Research On Imaging And Anti-deception Jamming For Synthetic Aperture Radar Of Two Different Systems

Posted on:2013-04-12Degree:MasterType:Thesis
Country:ChinaCandidate:F GaoFull Text:PDF
GTID:2248330377458663Subject:Signal and Information Processing
Abstract/Summary:PDF Full Text Request
Synthetic aperture radar (SAR) is a type of high-resolution imaging radar. Most of thetraditional transmitted signal for SAR is Linear Frequency Modulation (LFM) signal, whichhas shortcomings in the complex electromagnetic environment. So the Frequency ModulatedContinuous Wave (FMCW) signal was considered as the transmitted signal for the studyingof imaging and anti-jamming methods of FMCW-SAR. This paper is mainly reflected in thefollowing areas:The first chapter introduced the history and research situation of the imaging andanti-jamming for SAR.Then it discussed the imaging geometry and two-dimensional model for SAR. The formof transmitting signals and the form of the echo signals of LFM-SAR and FMCW-SAR wereanalyzed respectively, based on which part of the system parameters were calculated. Theclassification, anti-jamming measures and the merits of SAR are discussed.The imaging algorithms were given for SAR with banding patterns and airborneplatforms: Range-Doppler (RD) algorithm and Chirp Scaling (CS) algorithm for squintLFM-SAR, and RD algorithm for squint FMCW-SAR. The simulation results testify that theLFM-SAR and the FMCW-SAR imaging can be achieved with the proper imaging algorithmsand geometric correction when the oblique angle was60°.Later on the anti-jamming methods for LFM-SAR and FMCW-SAR were studied. Theeffectiveness of the anti-jamming method of jittering chirp rate polarity combined withamplitude limitation after adding random initial phase into the transmitting signal forLFM-SAR was discussed. The simulation results show that the jamming signal ratio can beincreased to55dB by this method. After the pulse repetition frequency (PRF) is increased, theanti-jamming method of random initial phase combined with amplitude limitation forFMCW-SAR was proposed. The simulation results testify that the jamming signal ratio (J/S)can be increased to46dB by this method.The last chapter summarized the paper and pointed out the deficiencies.
Keywords/Search Tags:Synthetic aperture radar (SAR), Linear Frequency Modulation (LFM), Frequency Modulated Continuous Wave (FMCW), anti-jamming
PDF Full Text Request
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