On Measuring Ship Height by Using Monocular Vision

With the growth of waterborne transportation and the increasing number of bridges, the risk of ship-bridge collisions has risen. This paper aims to design a ship height measurement system for practical scenarios. The system's hardware mainly consists of a monocular camera, an AIS receiver, and a phased array radar. Cameras are installed on the bridge to monitor ships, and the obtained data is uploaded to the server for processing. After preprocessing and fusion of the data, the system performs target detection and perspective transformation on the ships. Then, utilizing the pinhole imaging principle and data from various sensors, the system calculates the height and displays it on the user terminal. Both simulation experiments and field trials have confirmed the effectiveness of the proposed method for measuring ship height, meeting the necessary criteria. Moreover, the method exhibits low errors even at long measurement distances, enabling the system to issue alarms for ultra-tall ships from a distance. This paper presents a physical experiment, and the experimental results demonstrate that the measurement error is less than 0.6 m, thus confirming the effectiveness of the proposed algorithm.