基于回波相关性的三维成像声呐多帧积累方法  

Multi-frame Integration Method for 3D Imaging Sonar Based on Echo Correlation

作　　者：王硕[1,2,3] 刘纪元[1,2] WANG Shuo;LIU Jiyuan(Institute of Acoustics,Chinese Academy of Sciences,Beijing,100190,China;Key Laboratory of Science and Technology on Advanced Underwater Acoustic Signal Processing,Beijing,100190,China;University of Chinese Academy of Sciences,Beijing,100049,China)

机构地区：[1]中国科学院声学研究所,北京100190 [2]中国科学院先进水下信息技术重点实验室,北京100190 [3]中国科学院大学,北京100049

出　　处：《网络新媒体技术》2023年第4期32-41,57,共11页Network New Media Technology

摘　　要：三维成像声呐是一种用于拍摄水下三维场景的多波束声呐系统,在同一位置对场景多次观测后进行叠加,可以平滑图像噪声,提高信噪比。然而由于声速传播慢,且水下拍摄姿态容易受到环境扰动,成像设备无法在多个脉冲时间内保持姿态稳定,从而使得多帧数据无法有效积累。本文针对目标静止的场景,提出了一种声呐运动估计和补偿的方法,该方法首先利用2帧回波之间的相关性分别对时延和转动角度进行估计,根据运动参数对回波进行配准,将配准后的多帧声图进行非相干积累来提高声图质量。实验表明,该方法能够提升多帧积累的效果,多帧积累后的三维声图具有更低的图像信息熵,在相同的阈值设置下,补偿后获得的点云图像能够保留更完整的目标形态以及更少的背景噪点。3D imaging sonar is a multi-beam sonar system used to capture underwater 3D scenes,where multiple observations of the scene at the same location are superimposed to smooth out image noise and improve the signal-to-noise ratio.However,due to the slow propagation of sound velocity and the susceptibility of the underwater shooting attitude to environmental perturbations,the imaging device is unable to maintain a stable attitude over multiple pulse times,which in turn prevents the effective integration of multiple frames of data.In this paper,we propose a method for estimating and compensating sonar motion in a stationary target scenario.The method first uses the correlation between two echo frames to estimate the time delay and rotation angle respectively,then aligns the echoes according to the motion parameters,and accumulates the aligned multi-frame acoustic images in a non-coherent way to improve the acoustic image quality.Experiments show that the method can improve the effect of multi-frame integration,and the 3D acoustic image after multi-frame integration has lower image information entropy.Under the same threshold setting,the point cloud image obtained after compensation can retain more complete target shape and less background noise.

关 键 词：水声成像 三维声成像 运动估计 非相干积累 互相关 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] TB565[自动化与计算机技术—计算机科学与技术] U666.7[交通运输工程—水声工程]