Study On The Forward-looking Imaging Techniques For Airborne Radar

In recent years,forward-looking radar imaging techniques are growing more and more important and there are many applications in civil and military fields.Forward-looking imaging techniques are indispensable for aircrafts landing,marine search,precise guiding of missiles,and fighter reconnaissance,but the development of forward-looking imaging techniques are not mature.In the article,firstly,we discussed monopulse forward-looking imaging technique and deconvolution forward-looking imaging technique;and then we analyzed the imaging principle of them.The main research contents are as follows:1 The technique of monopulse forward-looking imaging is studied.Based on the monopulse angle measurement technique,the azimuth resolution of the forward-looking imaging is improved and the performance of monopulse angle measurement is analyzed.The simulation results show that this technique can improve the azimuth resolution effectively,but the improvement of the azimuth resolution is a non-uniform improvement.2.The multi-targets discrimination algorithm of monopulse forward-looking imaging is studied.It is difficult to discriminate multiple targets in the same range bin for monopulse angle measurement.Based on sum-channel and diff-channel Sinc function pulse compression,a maximum likelihood model in terms of azimuth angle,horizontal angles and range parameter is established to realize multi-targets discrimination.The simulation results show the correctness and the effectiveness of the proposed method.3.The deconvolution forward-looking imaging technique based on regularization is studied.The cause of ill-posedness in the deconvolution algorithm is analyzed,and the regularized deconvolution method is introduced.The theoretical analysis proved the feasibility of the regularization method to suppress the ill-posedness characteristics.Then,several main regularized deconvolution methods are studied,and the performance is estimated in terms of SNR.We applied the method to the actual forward-looking imaging process,and the forward-looking point image and forward-looking scene image of regularization-based method is obtained by simulation.The simulation results show that the regularization-based forward-looking imaging method can suppress the noise effectively.