建立了后向散射光在二维光敏面上能量分布的理论模型,结合典型水下激光成像系统,提出用像面表观衬比度来评价系统极限探测距离的方法,并推导了计算公式;通过选取水下激光成像系统的典型参量进行模拟计算,进一步讨论了系统主要组成部分的相对位置对像面表观衬比度分布的影响;得到像面表观衬比度与目标距离的关系曲线以及系统极限探测距离随海水衰减系数的变化曲线,从而估算出不同水质条件下系统的极限探测距离。模拟仿真数据与实际实验结果基本一致。

A theoretic model was built about the distribution of optical backscattering energy on the two dimensional photosensitive surface. Then, applied to typical underwater laser imaging system, a method was proposed to calculate the maximum detecting distance according to the apparent contrast. The theoretic calculations were programmed, and the variances of the apparent contrast were discussed when changing the relative position of some components. The relationship curve between the apparent contrast and the target distance as well as the curve between the maximum detecting distance and the attenuation coefficient were obtained, so that the maximum detecting distances could be estimated in different kinds of water quality, which are consistent with the actual experimental results.