Research Of Time-delay And Phase-shift Beamforming Technology

Sonar is a kind of important electronic equipment.It is an acoustic equipment that can detect, orientate,track and recognize the target underwater,and it also can communicate,navigate,control and guide, command weapon'shot and counterwork by using sound wave.Not only in the active sonar but also in the passive sonar beamforming system is the most important part of modem sonar.Beamforming system is the basement that makes sonar have good strategic capabilities and technical capabilities. We can acquire enough SNR and high precision of target distinguiment.The purpose of sonar beamforming is making many gusts of basic matrix that the unit forms get at directivity fixing in advance the direction through suitable handle.Beamforming technology is a method that forms space directivity via dealt with various export of basic matrix ranged of certainly geometry shape.The purpose of the article is discussing several methods of beamforming,and give the emulations of time-delay beamforming,phase-shift beamforrning,DFT beamforming, interpolate beamforming, side band-shift beamforming and time delay-phase shift hybrid beamforming.The advantages and disadvantages and applicable range of those bemforming methods can be get by study,contrast them and by compare the influence of beamforming quality that changed with all kinds of parameters.To the digital beamforming method,it need a bigger sampling rate if it want to get a definite precision.But the high sampling rate brings more higher demand of hardwares of ADC,inpute data's transmission, memorizer etc.,and it also adds cost.Using digital interpolate can ensure the precision of beamforming that do not have to increase signal sampling rate.This article emphasize the method of digital interpolate combined with time delay-phase shift mixed beamforming.And analyse the errors that produced by this method.