This letter proposes a novel approach for compensating target height data in 2D seabed mosaicking for low-visibility underwater perception. Acoustic cameras are effective sensors for sensing the marine environments due to their high-resolution imaging capabilities and robustness to darkness and turbidity. However, the loss of elevation angle during the imaging process results in a lack of target height information in the original acoustic camera images, leading to a simplistic 2D representation of the seabed mosaicking. In perceiving cluttered and unexplored marine environments, target height data is crucial for avoiding collisions with marine robots. This study proposes a novel approach for estimating seabed target height using a single acoustic camera and integrates height data into 2D seabed mosaicking to compensate for the missing 3D dimension of seabed targets. Unlike classic methods that model the loss of elevation angle to achieve seabed 3D reconstruction, this study focuses on utilizing available acoustic cast shadow clues and simple sensor motion to quickly estimate target height. The feasibility of our proposal is verified through a water tank experiment and a simulation experiment.

翻译：本文提出了一种新颖的方法，用于在低能见度水下感知中对二维海底拼接中的目标高度数据进行补偿。声学相机因其高分辨率成像能力以及对黑暗和浑浊环境的鲁棒性，成为感知海洋环境的有效传感器。然而，成像过程中俯仰角的缺失导致原始声学相机图像缺乏目标高度信息，使得海底拼接仅呈现简化的二维表示。在感知杂乱且未经探索的海洋环境时，目标高度数据对于避免与海洋机器人发生碰撞至关重要。本研究提出了一种利用单一声学相机估计海底目标高度的新方法，并将高度数据整合到二维海底拼接中，以补偿海底目标缺失的三维维度。与经典方法通过建模俯仰角缺失来实现海底三维重建不同，本研究侧重于利用可用的声学投射阴影线索和简单的传感器运动来快速估计目标高度。我们通过水箱实验和仿真实验验证了所提方法的可行性。