Research On SAR Deception Jamming Key Technology

In recent years, SAR has made great progress and development with its excellent ability of information acquisition and researchers’ continuous efforts, which makes it more and more important in electronic warfare. With the development of SAR, interference and anti-interference technology for SAR has come into focus. Deceptive jamming technology has become the key point of SAR interference technology due to its feature of being deceptive and small power. The premise of deceptive jamming is that the interference signal needs to match accurately with the enemy’s relative parameters. So the non-cooperative SAR motion parameter estimation plays the most important role in achieving deception jamming.This thesis firstly introduces the SAR imaging principle and the principle of SAR deception jamming with emphasis on analyzing the influence of motion parameters on the results of SAR deception jamming. The obtaining of a similar linear frequency modulated signal of SAR is dependent on the Doppler Effect generated by the relative motion, a high azimuth resolution is obtained accordingly. Motion parameter estimation error will lead to the matched filter mismatch on azimuth, which will affect the imaging quality of deceptive jamming. Deriving from the pulse compression and the superposition of the same phase, it is concluded that the equation based on the deceptive jamming can be a criterion for the estimation of the motion parameters.Secondly, according to the feature of transmitting SAR in coherent pulse signal, motion parameter acquisition based on Doppler information is raised after taking account of the coherent signal. Doppler information requires pulse to cumulatively influence the real-time obtaining of motion parameters. In order to obtain the motion parameters of non-cooperative SAR in real time, we adopt the idea of passive location. The first way is to obtain the motion parameters by means of direction finding, and the second way is time difference measurement.At last, according to the idea of extended Kalman filter, joint with the direction finding and time difference locating method, we use direction finding and time difference as observation equation, using SAR uniform linear motion as the state equation, localizing and tracking by extended Kalman filter in order to obtain a higher accuracy of the position parameters and motion parameters. We verify the results of deceptive jamming based on motion parameter estimation, obtaining the motion parameters of the deception jamming.