Numerical calculation and characteristic analysis of multiple-beam laser reflection on random and rough sea surface

Abstract

Laser reflection characteristics from the random and rough sea surface are significant for laser detection on the sea surface, and most investigations of which used single-beam laser. However, the single-beam laser spot covers a small area on the sea surface, so that the detection result is influenced seriously by fluctuant sea surface. The application of multiple-beam laser would help to increase the efficiency of laser detection on the sea surface. In this paper, the multiple beams are generated by a single Gaussian beam with the beam splitter. Therefore, all the beams are Gaussian beams and have the same divergence angle with different incident angles and distances. This paper investigates the multiple-beam laser characteristics from the random rough sea surface with geometrical optics method. At first, the fractal method is used to simulate random and rough sea surface. Based on the fractal rough sea surface, the reflection characteristics of each laser beam are calculated with Gaussian beam reflection model on two-dimensional random and rough sea surface, which is derived with geometrical optics method. And then, synthesizing all of the single beam laser reflection characteristics, the multiple-beam laser characteristics from the random rough sea surface can be obtained. With this method, laser reflection characteristics from sea surface of different laser beams are numerical calculated and the comparative analysis of the results is given. Finally, the discussion of some parameters have affections on multiple-beam laser characteristics is also given.