Research On Electromagnetic Scatting And Infrared Radiation Characteristic Of The Kelvin Wake In Ocean Background

Sometimes it is difficult to detect the ship’s information directly. But the wake produced by the vessel is cannot eliminate as long as the ship is in motion. Through, through the detection of ship wake to obtain the specific parameters of ship is a practical method. In addition, the movement of waves will change the movement of the hull, thereby affecting the wake formation. The hull and wake has some influence on the wave also. The interaction between wave and ship wake is complex. For the convenience of calculation, sea surface and ship wake are superposed according to a certain proportion. There are many methods for detecting wake, the most common method are the electromagnetic and infrared detection.This paper briefly introduced some commonly used sea spectrum, such as PM spectrum Fung spectrum and Elh spectrum. The features of these kinds of sea spectrums are discussed. Monte Carlo method and double superposition method which are used to simulate the two-dimensional sea surface are studied in this paper.The author descripted and classified the wake of a ship traveling on the sea surface. The Kelvin wake and the internal wave are considered in ship wave simulation study, showing the three dimensional picture of wave height under different hull parameters and ship speed. The model of turbulence only shows the geometric model change with the distance from the stem, for there is no a concrete three dimensional model.Then this paper presented some frequently-used electromagnetic scatting calculation method including Kirchhoff approximation method, small perturbation method and two-scale method. The author was focus on the analysis of the two-scale method with the computing analysis. It is necessary for us to research the electromagnetic scatting of Kelvin wake which is the typical wave of vessels. The author researches the Elfouhaily sea spectrum and Kelvin wake model and establishes simulation models. In view of the characteristics of Kelvin wake and the E ocean, the author put forward modified Two-scale Method to study the electromagnetic scatting of the sea with Kelvin wake. The influences of wind direction, wind speed and ship’s speed on electromagneticscatting are also discussed in this paper, which are agreed with practical situation.Depending on the basic theory of infrared imaging, the define and experience formula of BRDF are also considered in this paper, then with the help of softer Mondtran4 the normalized infrared imaging of Kelvin wake and internal wake are presented under different parameters.