Research On Infrared Radiation Characteristics Of Naval Vessel Target In The Sea Background

With the widely application of infrared detection and guidance technology in the military field, the research on radiation characteristics of target have become the key issues in the field of infrared radiation both in China and abroad. In recent years, various countries attach great importance to the issue of sovereignty over territorial waters, while the powerful backing to safeguard the national interests is to enhanced naval forces. The naval vessel has become the focus of the study as the main tool in the sea battle. The research on infrared radiation characteristics of naval vessel can offer characteristic parameters for detecting it, meanwhile it also can provide theoretical basis for their own protection, which has become a hot topic in States Navy and the defense sector with its strong demand and application of practical military background.In this paper, a type of naval vessel is chosen to analysis the infrared radiation characteristics. First, according to the geometric dimensions and temperature estimates build simplified geometric model naval vessel reasonably and complete the grid division of it. And then calculated surface temperature distribution of naval vessel through numerical method before analyzing the characteristics of heat transfer model, simplifing the internal heat reasonably and reasonable boundary conditions and radiation models is chosen. The results show that the major infrared radiation source of a moving naval vessel including exhaust chimney, power cabin site and phased array radar surface. The highest temperature appears in the chimney flue outlet, is about 450 K. On the basis of the temperature distribution we prepare the program calculates the radiation characteristics in different naval vessel detection direction with the use of Monte Carlo ray tracing method. We workout the effect of duration of sunshine obtained, navigation direction and detection band on radiation characteristics of the naval vessel.In addition, naval vessel can not exist out of the sea background as the specific target in it, therefore it’s needed to establish an appropriate model to analyze sea surface infrared radiation characteristics. In this paper, reflection characteristics of sea surface is calculated by using Cox-Munk rough sea surface model, masking functions and programming combined with Monte Carlo method. It calculates the trends of sea surface radiance over the detect angle under different angles of incidence, different wind and different infrared wavelengths,combined with the bidirectional reflectance distribution function of rough sea surface,furthermore calculated and measured values are compared, the error does not exceed 15%.Infrared thermal imaging can visually analyze the contrast characteristics of the target and background, it also can identify the feature site for its recognition. From project demands, infrared image of sea background and naval vessel targets are simulated separately based on the coordinate transformation, projection rules and the attenuation of atmospheric transport. Then, fuse the infrared image of target and background and analysis of the infrared thermal imaging of naval vessel targets under sea background with different working condition. The results show that, due to the effects of atmospheric attenuation, as detection range increases, the maximum radiation brightness reducing naval vessel. Vertical is the best detection angle during the different detection zenith.