关键词: 水下地形, 分形布朗运动, 随机中点位移算法

Abstract: Due to the difficulty of obtaining water depth data，it is worthwhile to study the high-precision underwater terrain simulation with limited data.The fractional Brownian motion（fBm） model is used to compute fractal parameters of underwater terrain，and an interpolation algorithm combined with the random midpoint displacement method is implemented by Matlab.Furthermore，this paper studies the 3D underwater terrain simulation of Yangtze Estuary Deepwater Channel.The 3D terrain simulated is compared with those generated by Kriging and Inverse Distance Weighted（IDW）interpolation.And an isobath reconstruction method is employed to analyze their errors.The results show that the accuracy of fBm model is lower than that of Kriging，but higher than that of IDW.And the terrain generated by fBm model possesses rich surface detail and realistic visual effect，presents the complexity and irregularity of underwater terrain.

Key words: underwater terrain, fractional Brownian motion, random midpoint displacement algorithm