Research On Detection Of Underwater Vehicle Based On Infrared Characteristics Of Hot Wake

In recent years,friction between countries has become more frequent at sea,and submarines have received more and more attention due to their excellent concealment performance and powerful assault capability.The warm seawater discharged by the submarine movement can form a hot wake on the sea surface.With the development of infrared detection technology,the minimum temperature resolution of the infrared detection system can reach 0.001 K,which is enough to detect the abnormal temperature of the sea surface and identify the underwater vehicle's position,speed and direction.Therefore,it is necessary to study the hot wake of the sea from the perspective of infrared radiation.In this paper,the "wave class" nuclear submarine was taken as the research target.Based on the floating wake problem of the hot wake,the "flow method" was used to simulate the floating development law of the submarine hot wake in different seawater environments.Through the comparison of multiple sets of working conditions,the effects of different submarine speeds,different circulating water discharge flows and different circulating water discharge temperatures on the development of hot wake and the hot wake of sea surface were obtained.The obtained sea surface temperature distribution law shows that the development of hot wake is divided into four stage: initial stage,rapid cooling stage,slow cooling stage and steady temperature stage.The temperature change and the rising law of each stage are different.There are three main factors affect the temperature and the rising law of the hot wake: submarine sailing speed,circulating water discharge temperature and circulating water discharge flow rate.When the sea water temperature is uneven,the difficulty of lifting is significantly harder than when the sea water temperature is uniform.According to the infrared ranging problem of sea surface,the infrared radiation model of sea surface was established according to the sea surface temperature.The relationship between infrared radiation characteristics and wind speed and detector angle was analyzed,and the emissivity under different sea conditions was established.According to the principle of atmospheric radiation transmission,the variation law and influencing factors of infrared radiation in atmospheric transmission were studied.The infrared detection distance of sea surface's hot wake under different atmospheric conditions was calculated.The result shows that when the detection probability is less than 0.9,the relationship between the two shows a linear change.When the meteorological condition and the detection condition are fixed,the difference between the discovery distance and the recognition distance is large.When the meteorological condition or the detection angle changes,the discovery distance also changes,and the recognition distance hardly change.On this basis,aiming at the infrared imaging problem of sea surface's hot wake,the spatial simulation mapping model and the infrared simulation imaging model were used to process the infrared simulation image through noise processing,image enhancement and edge detection process to obtain a realistic and imaging effect.According to the results,different infrared imaging conditions and climatic conditions will affect the imaging effect.Different image processing methods have different effects when processing simulated images.