Research On Laser Active Polarization Imaging Of UAV Wreckage In Complex Environments

In complex environments,unmanned aerial vehicle(UAV)detection is applied more and more frequently.In unknown environments,UAV often encounters unpredictable problems or faults.How to quickly and accurately search for the wreckage of UAV in complex environments is an important question.Polarization imaging technology has a wide range of applications.It can not only obtain the intensity information of the imaging target,but also the polarization information that cannot be obtained by traditional intensity imaging.Polarization imaging detection technology can improve the target recognition rate in complex environments.In order to find the the wreckage of UAV effectively in complex environments,a search method based on laser active polarization imaging is proposed and experimented.The main research contents and work are as follows:(1)The fundamental theory of polarization imaging technology is researched;In advance,a degree of polarization(DOP)measurement experiment is performed on the drone rotor,fuselage carbon tube,grass and sand at the same angle of incidence by using a polarimeter.The experiment verifies the particularity of the UAV material’s polarization characteristic in complex environments and the effect of surface structure on polarization characteristic.(2)Based on the polarization imaging detection theory,a laser active polarization imaging system is set up,and polarization imaging experiments are performed on UAV components under three conditions(without background,in grass background,and in sand background)to obtain the polarization images and intensity images of the targets.By writing software of the upper computer,the polarization degree images of the target are calculated and compared with the intensity images.And the edge characteristic values are calculated respectively.The experimental results show that the total edge intensity of the polarization degree images obtained in the complex environments are 6.6228 times that of the traditional intensity images on average,indicating that this system has improved the edge characteristic of the drone wreckage images in the complex environments.(3)Aiming at the problem that laser images are susceptible to speckle noise,median filtering,homomorphic mean filtering and improved enhanced Lee filtering are used to filter the polarization degree images.The filtering experiment results show that compared with the other two filtering algorithms,the improved enhanced Lee filtering algorithm not only significantly suppresses speckle noise,but also effectively maintains the edge information of the images.In conclusion,the improved enhanced Lee filtering algorithm has more advantages in processing the polarization degree images obtained by the method of this article.