Research On Algorithms Of High Resolution Radar Targets

Nowadays,with the development of shipping industry,Marine navigation radar is widely used on the modes of sea surface target identification,collision,communication and navigation.The required resolution of radar target precision is higher and higher.Because of the limitation of environment and technical conditions,the method which depends on the bandwidth and radar antenna beam width to improve distance and azimuth resolution,is unable to achieve the ideal resolution.Therefore,the research of the radar target high resolution algorithm is more valuable.The performance of the radar resolution target mainly investigates from two aspects,namely the radar azimuth resolution and range resolution.Azimuth resolution is the minimum interval of radar distinguishing two target bearings on the same distance unit.And range resolution is the minimum distance interval of two targets which can be divided at the same bearing unit.In order to improve the radar azimuth and range resolution,two high resolution algorithms are proposed in this paper.They are deconvolution algorithms based on wiener filtering and exponential processing algorithm based on wavelet transform.Firstly,the paper expounds the principles of wiener filtering and deconvolution theory,analyzes the existing deconvolution methods,and puts forward the deconvolution algorithm based on wiener filtering.The paper selects single target echo model to simulate and verify the effectiveness of the algorithm.Furthermore the algorithm is applied to multi-objective echo models,obtaining the ideal target echoes.Afterwards,the paper quantitatively analyzes and compares the width of echoes before and after the wave,and determines the improved resolution ratio deconvolution times.After discussing the influences of signal-to-noise ratio to deconvolution effect,the result shows that the algorithm has higher requirement for signal-to-noise ratio over 30 db.The real radar signal is processed comparing with the image before to confirm that the result is effective.Secondly,with target normalization processing and wavelet transform theory,the author puts forward the power processing algorithm based on wavelet transform.Single target echo models are selected to detect backscatter of peaks and troughs using wavelet transform.Then the paper takes power process to normalize signals after normalization process,and achieves the high resolution after doing multiplication with waveform.To take multiple target echo model,the normalized signal is changed.The jumps are eliminated using the curve smoothing technology.As a result,the robustness of the algorithm is improved.To prove the feasibility of the algorithm,the paper takes process with the real radar images,and gets the high resolution effects.Finally,the paper transforms.m files into separate executable files,creates MFC window functions to display this topic research results using VC++ and MATLAB methods.