Underwater Complex Target Three-dimension Detection Using Gated Wavefront Sensing Technique

The 3D detection of underwater targets as a key technology has received extensive attention from governments of the world and scientific institutions in ocean exploration and development.It is used in many fields such as marine geodesy and cartography,underwater rescue.Due to the complexity of the underwater environment,it causes light disturbances during underwater transmission and makes the traditional three-dimensional detection method not suitable for underwater detection and reconstruction.Therefore,it has practical value for the 3D detection of the underwater complex targets.For various underwater reconstruction targets,underwater turbulence can be used as a representative underwater complex target due to its own characteristics of arbitrary shapes and high transients.And underwater turbulence testing can also be used as a derivative of target affects underwater target 3D detection.In this paper we combined wavefront sensing technique and range-gated technique,A underwater 3D detection system based on gated wavefront sensing technique was innovatively proposed.The complex turbulent three-dimensional surface is detected and reconstructed using Matlab.The three-dimensional detection performance of this method is verified by the reconstruction of different surface turbulences.First,we introduces the research status and principle of the three-dimensional detection of underwater targets.The gated wavefront sensing system is proposed.It can overcome the problem of low reconstruction accuracy caused by underwater scattering andn the process of 3D detection.According to the characteristics of underwater turbulence and the characteristics of surface features,the wavefront detection algorithm is used to threshold segmentation and denoise the acquired underwater target images.Then the working process of the gated wavefront sensing system is described in detail.Accurately control gated camera gating times by introducing time-of-flight technology(TOF),It can avoid the interference of underwater scattering light and other environmental factors,improve the detection accuracy of turbulent surface.Finally,a series of verification experiments were carried out for the method propose.Different types of turbulent targets are created by different depths and different flow rates.The performance of surface reconstruction of this method is demonstrated through reconstruction results.