Influence of Wavy Sea Surface on Laser Detection of Underwater Target with Monte Carlo Method

2012 ◽  
Vol 39 (7) ◽  
pp. 0702003
Author(s):  
章曦 Zhang Xi ◽  
李配军 Li Peijun ◽  
吴方平 Wu Fangping ◽  
吴王杰 Wu Wangjie ◽  
蒋敏 Jiang Min
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Sea Surface ◽  
Laser Detection ◽  
Underwater Target

scholarly journals Comparative Study on Numerical Calculation of 2-D Random Sea Surface Based on Fractal Method and Monte Carlo Method

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1871
Author(s):  
Gengkun Wu ◽  
Chuanxi Liu ◽  
Yongquan Liang
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Calculation Model ◽  
Sea Surface ◽  
Wave Direction ◽  
Fractal Function ◽  
Orthogonal Direction ◽  
Fractal Method ◽  
Numeric Calculation ◽  
Directional Distributions

Based on fifty one groups of data on direction distribution measured from buoy sites, several important spectrum parameters including distribution characteristics of the measured data’s spectrum, the Wen’s direction spectrum and the Donelan function are analyzed from the perspectives of standard deviation of directional distribution function and statistical results. Then, a numeric calculation model based on the Monte Carlo method is proposed in this work. At the same time—based on Weierstrass self-affine fractal function—numeric simulation of random sea surface is conducted by modifying the bilateral power law. The analysis of the numeric calculation results under different wind directions, speeds and fetches proves that both methods can be adopted for different water directional distributions and target spectrum models. In addition, this study compares the characteristic wave within different distribution frequency domains in the main wave direction and in its orthogonal direction. It is proved that the fractal method cannot fully reflect the anisotropy of gravity wave and tension wave in the superposition direction, however, it can maintain the similarity of overall energy part with the rough length of the waves. Moreover, there are still limitations of the fractal method in the numeric modeling of undeveloped sea surface.

Influence of Wavy Sea Surface on Airborne Lidar Underwater Beam Quality with Monte Carlo Method

2008 ◽  
Vol 35 (2) ◽  
pp. 178-182 ◽  
Author(s):  
夏珉 Xia Min ◽  
杨克成 Yang Kecheng ◽  
郑毅 Zheng Yi ◽  
饶炯辉 Rao Jionghui
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Beam Quality ◽  
Airborne Lidar ◽  
Sea Surface

Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
Author(s):  
Zdenek Sekanina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Interplanetary Space ◽  
Porous Matrix ◽  
Maximum Diameter ◽  
Expansion Velocity ◽  
Solid Constituent ◽  
Meteoric Material ◽  
Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

Structures and crystallization of vacuum-deposited amorphous Se and Sb films

1990 ◽  
Vol 48 (4) ◽  
pp. 140-141
Author(s):  
Makoto Shiojiri ◽  
Toshiyuki Isshiki ◽  
Tetsuya Fudaba ◽  
Yoshihiro Hirota
Keyword(s):  
Monte Carlo ◽  
Electron Microscope ◽  
Monte Carlo Method ◽  
Computer Program ◽  
Radial Distribution ◽  
Film Formation ◽  
Amorphous State ◽  
Two Dimensional ◽  
Amorphous Films ◽  
Binding Condition

In hexagonal Se crystal each atom is covalently bound to two others to form an endless spiral chain, and in Sb crystal each atom to three others to form an extended puckered sheet. Such chains and sheets may be regarded as one- and two- dimensional molecules, respectively. In this paper we investigate the structures in amorphous state of these elements and the crystallization.HRTEM and ED images of vacuum-deposited amorphous Se and Sb films were taken with a JEM-200CX electron microscope (Cs=1.2 mm). The structure models of amorphous films were constructed on a computer by Monte Carlo method. Generated atoms were subsequently deposited on a space of 2 nm×2 nm as they fulfiled the binding condition, to form a film 5 nm thick (Fig. 1a-1c). An improvement on a previous computer program has been made as to realize the actual film formation. Radial distribution fuction (RDF) curves, ED intensities and HRTEM images for the constructed structure models were calculated, and compared with the observed ones.

Sign in / Sign up

Export Citation Format

Share Document