基于导航X波段雷达图像的海岸线检测方法研究  

Study on the Method to Detect Coastline from Navigation X-band Radar Images

作　　者：范仲珏 何宜军 陈忠彪 FAN Zhongjüe;HE Yijun;CHEN Zhongbiao(School of Marine Sciences,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学海洋科学学院,江苏南京210044

出　　处：《遥感技术与应用》2023年第3期739-751,共13页Remote Sensing Technology and Application

基　　金：国家自然科学基金面上项目(41977302);江苏省海洋科技创新专项项目(HY2018-12)。

摘　　要：海岸线的变化影响着沿海居民的生产生活和国家军事战略部署,快速、准确地检测海岸线变化有着重要意义。导航X波段雷达可以连续、实时检测近岸海洋环境,研究提出了一种利用导航X波段雷达图像检测海岸线的方法。首先,对导航X波段雷达图像进行平均、对比度增强和高斯滤波等预处理,降低海杂波噪声对雷达图像的影响;然后,将预处理后的图像与边缘检测算子进行卷积运算获得梯度图像,建立了基于直方图双峰法的自适应阈值估算方法,从梯度图像中自动提取出目标岛屿的边界;最后,利用边缘膨胀、空洞填充和去噪提取完整的岛屿,并估算岛屿的面积和周长等参数。利用实验观测的导航X波段雷达图像对提出的方法进行验证,与电子海图和Google Earth地图中的海岸线相比,根据Sobel算子和Prewitt算子提取的目标岛屿的边缘精度较高,提取岛屿的面积和周长随潮汐高度、海况等而变化。结果表明:导航X波段雷达能有效监测到岛屿海岸线的实时变化。The change of coastline affects the production and life of coastal residents and the national military strategic deployment.It is of great significance to detect the change of coastline quickly and accurately.Naviga⁃tion X-band radar can continuously and real-time detect the nearshore marine environment.This paper proposes a method to detect coastline using navigation X-band radar images.Firstly,the navigation X-band radar image is preprocessed by averaging,contrast enhancement and Gaussian filtering to reduce the impact of sea clutter on the radar image;Then,the preprocessed image and the edge detection operator are convolved to obtain the gra⁃dient image,and an adaptive threshold estimation method based on the histogram bimodal method is established to automatically extract the boundary of the target island from the gradient image;Finally,the edge expansion,cavity filling and denoising are used to extract the complete island,and the area and perimeter of the island are estimated.The proposed method is verified by using the navigation X-band radar images observed in the experi⁃ment.Compared with the coastline in the electronic chart and Google Earth map,the edge accuracy of the target island extracted by Sobel operator and Prewitt operator is higher,and the area and perimeter of the extracted is⁃land vary with the tide height,sea conditions,etc.The results show that the navigation X-band radar can effec⁃tively monitor the real-time changes of the island coastline.

关 键 词：X波段雷达 边缘提取算法 海岸线检测 

分 类 号：P71[天文地球—海洋科学]