Research On Laser Underwater Target Polarization Imaging Technology Based On Focal Plane Method

Underwater target detection is an important research area in military direction.As an emerging target detection technology,polarization spectral imaging technology has the advantages of polarization imaging and spectral imaging.Its target image contains the characteristic information of polarization and spectrum.Compared with the conventional intensity or spectral target image,it can suppress background noise.Improve underwater target detection capabilities.Based on the principle of polarization spectrum detection,an underwater polarization spectrum imaging system based on the defocus plane method is established in this paper.The system is mainly composed of laser,polarizer,quarter-wave plate,liquid crystal tunable filter(LCTF),and focal plane polarization.The camera is composed of polarized images of underwater objects at multiple angles at the same time,and polarized detection of three bands of red(R),green(G),and blue(B)can be achieved by tuning liquid crystal tunable filters.Then,by extracting the polarization and spectral information of the target image,the image is subjected to polarization spectrum fusion processing to improve the detection ability of the underwater target,realize the detection of the underwater target,and obtain the expected image.The results show that compared with the traditional light intensity image,the fusion image obtained in this paper has a significant improvement in image contrast and quality.In addition,through underwater detection experiments,the effects of factors such as sediment concentration in water,underwater target materials,and underwater targets in different bands on the underwater target polarization spectrum imaging were studied.The experimental results show that compared with the traditional light intensity detection results,the underwater polarization spectrum imaging system based on the defocus plane method proposed in this paper can better obtain the relevant information of underwater targets;the effect of sediment concentration in water on the acquisition of polarized images is relatively small.but the approximate outline of the target object can still be obtained when the sediment concentration is low;Under clearer water environment,the imaging effect of underwater targets in green(G)and blue(B)bands is better;This article selects metal,ceramics and plastics.Studies have shown that ceramics have the best imaging effect,followed by metals,and finally plastics.