The Research Of SAR Imaging And Detection Of Foliage-concealed Target Based On P-band

Synthetic Aperture Radar(SAR)has great advantages in target detection,which is widely used in the military field.In order not to be detected easily,military targets are often hidden in forest areas.Because of the occlusion of trees,radar detection will be restricted.Compared with the short-wave band,the P-band electromagnetic wave has longer wavelength,less attenuation when penetrating the tree canopy,good penetration ability for foliage,and can obtain information of targets in the forest area.However,the strong echo of tree trunk will cause interference to the target detection.This thesis tries to solve the main problems faced by the P-band to detect the foliageconcealed target through theoretical analysis and practical verification.Firstly,the Penetration ability of P-band electromagnetic waves and the scattering characteristics of tree trunks and targets under the irradiation of P-band electromagnetic waves are analyzed.Based on the results,the detection method of foliage-concealed target is investigated.Finally,the research results are verified by simulation and actual data.The main research contents include:1.The penetration ability of P-band radar waves to soil and foliage is studied.First,from theoretical point of view,a quantitative expression of penetration characteristics of P-band is obtained.Then calculating its penetration ability using actual data,which shows the feasibility of P-band electromagnetic waves to detect targets concealed by foliage.2.The electromagnetic scattering characteristics of truck targets and tree trunks is researched.Firstly,the theoretical analysis of the scattering characteristics of them is carried out.Secondly,based on the penetration characteristics of the P-band,through modeling and simulation,the electromagnetic scattering characteristics of the tree and truck targets under the conditions of P-band electromagnetic wave are obtained.The difference between them is obtained too,which provides a theoretical basis for the research on the detection method of foliage-concealed targets.3.The improvement of traditional imaging algorithms under P-band conditions is researched.Compared with other radar bands,SAR imaging operating in the P-band faces more problems.Therefore,it needs to be improved on the basis of the traditional imaging method to make it more suitable for the P-band.This part provides support for the research of target detection methods.4.The detection method of foliage-concealed target based on P-band SAR is researched.Firstly,the feasibility of some existing traditional detection methods based on scattering intensity is verified,and the detection results are optimized through median filtering and morphological operations.Secondly,combined with the difference between the scattering characteristics of the truck target and the tree trunk,the detection method based on the spatial characteristics is studied.Finally,combined with the actual data and correlation principle,a new detection method based on correlation is proposed.