侧扫声呐图像反演海底地形的一种线性算法

摘要

为弥补现有测深方法在获取海底微地形方面的不足,基于侧扫声呐高分辨率成像特点,提出一种侧扫声呐图像反演三维海底绝对地形的线性化算法.首先,根据侧扫声呐成像原理给出声波入射方向的估算模型,基于海底表面漫反射模型推导出一种线性化反演模型,并以同区域初始地形作为约束建立反演地形的约束模型,实现了反演地形向绝对地形的转变;在此基础上,给出完整的侧扫声呐图像反演三维海底绝对地形的流程以及精度评定方法;最后,借助实验对该方法进行了检验和验证.实验结果表明,该方法可以获得均方根误差优于15 cm、分辨率为初始地形170倍的海底地形.%To make up for the deficiencies of existing sounding method in obtaining the seabed microtopography,a linear algorithm to obtain three-dimensional sea topography using side scan sonar image based on its high resolution features is proposed.Firstly,the incident sound direction estimation model is given according to the side scan sonar imaging mechanism,and the linear inversion algorithm is derived from the seabed lambert model.Meanwhile,the constraint model is built using the initial terrain data of the same area,and the transform from inversion topography to real topography is completed.Based on the above,the inversion process and the accuracy evaluation method are finally achieved.Lastly,experiments are carried out to test and verify the given method.Experimental results show that this method can obtain the topography whose accuracy is better than 15 cm and whose resolution is about 170 times higher than that of the initial terrain.