A non-invasive, low-cost and easy-to-operate underwater terrain monitoring method

A fast, reliable, through water and non-intrusive bed-profile measurement technique that is economical and easy to use in a wide range of laboratory experiments involving sediment transport is proposed. A consumer-grade 3-D range sensing technology which by its low cost, easy operation and relatively good accuracy is becoming an attractive alternative to expensive 3-D laser scanners. The Microsoft XBOX 360 kinect sensor 2.0 is a low-cost and highly popular depth camera, which can be used to scan 3D surface terrain of dynamic objects and has the potential to scan terrain below and above water. Through the software matching of kinect 2.0, a data storage and analysis system are formed, which makes it has the ability to obtain underwater terrain data. In addition, the correction model of water refraction error is established, which can eliminate the measurement error caused by water refraction. Up to four different water conditions, kinect 2.0 is tested. Finally, the influences of water depth, suspend load volume concentration and moving flow velocity on the measurement accuracy of kinect 2.0 are explored, and the compensation methods of measurement error caused by the above factors are given. The results of this paper can provide reference for underwater topographic survey.