The Mechanism And Experimental Research On Passive Terahertz Radiation Detection Of Aerial Targets

In the current complex international environment and national defense security threats,passive detection of aerial stealth targets is particularly important.In order to be better applied to military environment,this paper studies the mechanism of passive detection of aerial targets,constructs passive detection models of aerial targets suitable for different weather and different environments,and measures the radiation characteristics of typical targets and landforms.The focus is on the relationship between the important parameters(reflectivity,scattering rate)of the target(and landform)radiation characteristics and its material,polarization,and roughness.In order to estimate the detection distance more accurately,the atmospheric transmission characteristics of terahertz and millimeter wave signals are also analyzed in detail,the sky background brightness temperature under different weather conditions(sunny,fog,and rain)are compared.The corresponding atmospheric attenuation coefficient and refractive index are analyzed.Finally,a complete terahertz/millimeter wave frequency band passive detection radiation brightness temperature simulation system for aerial targets was built,and the brightness temperature of different weather,different landforms,and different altitudes were simulated,and the radiation characteristics and the appearance of the target were compared and analyzed.The relationship between materials,etc.,and the maximum distance of passive detection under different frequency bands are evaluated.In the analysis process,the classical principles of electromagnetics and the MPM weather model are used.In the end,a radiation detection model for aerial targets was constructed and simulated,and a measurement scheme to achieve high-precision,large-range,and long-distance detection of aerial targets was given.Based on the experimental conditions,the voltage method was selected to measure the radiation characteristics of the target on the spot,and the results were compared with the simulation results.The establishment of the air target detection model and the study of its mechanism are of great significance to the overall construction of a millimeterwave air target imaging system that can quickly determine the presence or absence of a target and perform target recognition.