The Thz-band Sar Imaging And Micro-doppler Target Detection And Separation Technology Research

Frequency range of THz waves is 0.1THz to 10THz.Compared with micro waves, SAR imaging with THz waves can reach high resolution and can work at any situation. Compared with optics,SAR imaging with THz waves has strong penetration.On the aspect of low speed target measurement,it is easy to fufill low speed target measurement due to obvious doppler effect of target with THz wave.So imaging of super resolution and target measurement of micro-doppler with THz wave are high value research.So we can forsee that THz Radar will be the important member of Radar system and will make significant effect.We have not seen about research on this aspect. Based on these,this dissertation has done some research on THz wave SAR imaging and micro-doppler target recognization.The contributions are calculated as following:1.Imaging of THz waves is compared with X waves.THz waves with RD using shorter synthetic aperture length can achieve the same azimuth resolution as X waves and range migration correction does not need for THz waves.2.Errors on SAR imaging with THz waves are researched.Models of relative errors of carrier frequency,motion errors of low frequency,and high frequency vibration are set up and we analyze their influences on THz imaging compared with X waves.High frequency vibration has more influence on THz waves compared with X waves.High frequency vibration becomes the key problem of THz SAR imaging.3.For high frequency vibration on THz SAR imaging,a parameter estimate method of high frequency vibration is presented.This dissertation set up SAR echo model with high frequency vibration.Based on this model,we combine DCFT with LFM decomposition and present a new parameter estimate method of high frequency vibration.Simulations demonstrating,this method can suppress influence of high frequency vibration effectively.4.Low speed target recognition methods of micro-doppler are researched. Simulations demonstrate that it is easy to use time-frequency analysis to measure low speed target and THz wave has more doppler effect compared with X wave. 5.Low speed target measurement methods of micro-doppler are researched.In this dissertation,Independent Component Analysis(ICA) is used for micro-doppler target recognization of THz waves.Simulations demonstrate that this method can recognize targets effectively.