海洋激光雷达在探测水下目标时，其探测深度会受到波动水面的影响。对于光子在目标平面上的空间分布，已经成为研究的热点。而已有工作多集中在光子径向分布半径较小的情形，对于光子在目标平面大范围的扩散情形研究较少。基于蒙特卡罗方法，通过对比舍选抽样法和变换抽样法，光子径向分布半径较大的情形得以分析。结果显示，对于相同半径，光子径向相对能量分布与风速满足一定的规律。这说明，由于风速影响所产生的随机性并不是完全随机，也有一定的规律性。同时，舍选抽样法和变换抽样法的对比显示，变换抽样法作为一种近似，其结果没有舍选抽样法精确。

When oceanic lidar detects the underwater target, the detection depth will be influenced by the wavy surface. The spatial distribution of the photons on the target plane has already become the focus of the research. Most of the work that has been done is about radial distribution of photons in the small-radius region, while research about the photon diffusion on the target plane in wider region is very little. Based on Monte Carlo method, through the comparison between abandon and select sampling and transform sampling, the radial distribution of photons in big-radius region has been analyzed. The results show that, for the same radius, the radial distribution of the photons′ relative energy and the wind speed follow some rules. That means the randomness due to the wind speed is not completely random, there are some rules too. Meanwhile, the comparison between abandon and select sampling and transform sampling shows that transform sampling is only as an approximation, and its result is not as accurate as abandon and select sampling.