﻿ SAR技术在舰船海面溢油监测系统的应用
 舰船科学技术  2023, Vol. 45 Issue (10): 139-142    DOI: 10.3404/j.issn.1672-7649.2023.10.027 PDF
SAR技术在舰船海面溢油监测系统的应用

Application of SAR technology in marine oil spill monitoring system
SUN Jian-ming, WANG Ren-qiang, LIU Chang-hua
School of Navigation Technology, Jiangsu Maritime Institute, Nanjing 211170, China
Abstract: Because of the devastating damage of oil spills to the marine ecosystem, it is necessary to monitor the sea surface all day and all weather, however, the current oil spill monitoring system has some disadvantages, such as small monitoring range, limited monitoring time and high cost. In this paper, an oil spill monitoring system based on synthetic aperture radar is constructed. The principle of oil film imaging, image interpretation and the performance of the system are studied, the system can not only monitor the sea surface all day and all weather, but also distinguish oil film types and estimate oil film characteristics. The maximum detection rate can reach about 91% .
Key words: oil spill     remote sensing technique     SAR
0 引　言

1 合成孔径雷达及工作原理

SAR的工作原理如图1所示，天线沿垂直于平台的方向进行匀速运动，并对斜下方的目标进行观测。在此过程中，每隔一段时间，SAR会向地面或海面发射脉冲信号，并在不同的位置接收、记录、存储目标返回的信号（包括回波信号的强度和时间延迟），再对这些不同位置上接收到的信号进行合成处理，生成SAR数据[2]

 图 1 SAR的工作原理示意图 Fig. 1 Schematic diagram of SAR working principle

SAR以速度 ${v_a}$ 沿 $X$ 方向进行匀速直线飞行，飞行高度为 $h$ ${\theta _r}$ 表示垂直波束角， ${\theta _\alpha }$ 为航向波束角， $W$ 为测绘带宽， ${L_{\max }}$ ${L_{\min }}$ 分别表示最大合成孔径长度和最小合成孔径长度。被测目标可以视为一理想点 $p$ ${R_0}$ $p$ 与航线 $X$ 间的垂直斜距。

 $R = \sqrt {{R_0}^2 + {{({x_a} - {x_p})}^2}} \text{。}$

 $R = \sqrt {{R_0}^2 + {{({x_a} - {x_p})}^2}} \cong {R_0} + \frac{{{{({x_a} - {x_p})}^2}}}{{2{R_0}}} \text{，}$

 $W = {R_f} - {R_n} \text{。}$

 ${R_f} = h \cdot \tan \Bigg(\theta + \frac{{{\theta _r}}}{2}\Bigg) \text{，} {R_n} = h \cdot \tan \Bigg(\theta - \frac{{{\theta _r}}}{2}\Bigg) \text{。}$

2 海面溢油监测系统 2.1 系统整体设计

 图 2 基于SAR的海面溢油监测系统示意图 Fig. 2 Schematic diagram of oil spill monitoring system based on SAR

2.2 油膜成像原理

 图 3 油膜成像原理示意图 Fig. 3 Schematic diagram of oil film imaging principle
2.3 图像处理方法

 图 4 各滤波器平滑指数SI对比 Fig. 4 Comparison of filter smoothness index SI

2.4 油膜厚度和面积估算和漂移模型

 $h = \frac{{{\rho _{oT}}}}{{\left( {{\rho _w} - {\rho _{oT}}} \right)s}}{\left( {\frac{{ - 179{W^{{\raise0.5ex\hbox{$\scriptstyle 4$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 3$}}}}t + \sqrt {{{\left( {179{W^{{\raise0.5ex\hbox{$\scriptstyle 4$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 3$}}}}t} \right)}^2}} + 30940{t^{{\raise0.5ex\hbox{$\scriptstyle 1$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 2$}}}}S}}{{15\;470{t^{{\raise0.5ex\hbox{$\scriptstyle 1$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 2$}}}}}}} \right)^3} \text{。}$

2.5 实验结果

 图 5 SAR溢油监测系统输出图像 Fig. 5 SAR oil spill monitoring system output image

 图 6 溢油监测探测率 Fig. 6 Oil spill monitoring detection rate

3 结　语

 [1] 于秋则. 合成孔径雷达(SAR)图像匹配导航技术研究[D]. 武汉. 华中科技大学, 2004. [2] 牛莹. 基于纹理特征的星载SAR溢油监测研究[D]. 大连. 大连海事大学, 2009. [3] 石立坚. SAR及MODIS数据海面溢油监测方法研究[D]. 青岛. 中国海洋大学, 2008. [4] 蒋旭惠, 张汉德, 董梁, 等. 机载SAR在海冰航空监测中的应用研究[J]. 海洋开发与管理, 2014, 31(5): 44-47. JIANG Xu-hui, ZHANG Han-de, DONG Liang, et al. Application of airborne SAR in sea ice aerial monitoring[J]. Ocean Development and Management, 2014, 31(5): 44-47. DOI:10.3969/j.issn.1005-9857.2014.05.011 [5] 吴晓丹, 宋金明, 李学刚, 等. 海上溢油量获取的技术方法[J]. 海洋技术, 2011, 30(2): 50-54+58. WU Xiao-dan, SONG Jin-ming, LI Xue-gang, et al. Technical methods for marine oil spill quantity capture[J]. Ocean Technology, 2011, 30(2): 50-54+58. [6] 陈彦彤, 李雨阳, 吕石立, 等. 基于深度语义分割的多源遥感图像海面溢油监测[J]. 光学精密工程, 2020, 28(5): 1165-1176. CHEN Yan-tong, LI Yu-yang, LV Shi-li, et al. Research on oil spill monitoring of multi-source remote sensing image based on deep semantic segmentation[J]. Optics and Precision Engineering, 2020, 28(5): 1165-1176. [7] 覃睿, 闫玲, 陈子健. 无人机海上溢油跟踪监测系统设计及仿真[J]. 海洋通报, 2021, 40(6): 709-715. QIN Rui, YAN Ling, CHEN Zi-jian. Design and simulation of UAV oil spill tracking and monitoring system[J]. Marine Science Bulletin, 2021, 40(6): 709-715. DOI:10.11840/j.issn.1001-6392.2021.06.011