共查询到14条相似文献,搜索用时 62 毫秒
1.
溢油污染不仅会造成巨大的经济损失,而且给生态环境带来难以修复的破坏。准确、高效地监测海面溢油仍是当前亟需解决的问题。紫外传感器对油膜非常敏感,可快速发现,但存在误判;而SAR(SyntheticApertureRadar)溢油探测的精度较高,两者相结合可准确探测溢油。无人机平台可低成本地实现溢油快速应急响应,无人机载SAR和紫外传感器的载荷重量小,可同时集成于无人机上开展联合溢油探测,以满足业务化监测需求,此方面的研究尚未见有相关报道。本文拟研究溢油不同种类、厚度、在不同海洋环境条件下的紫外图像特征和SAR纹理特征、形状特征、散射特征,构建溢油特征数据库,并建立一种基于特征组合的溢油SAR与紫外联合探测方法;在此基础上研究对无人机数据获取模式和控制单元等的改造方案,进而实现溢油SAR和紫外图像的高效获取。 相似文献
2.
全极化SAR图像中溢油极化特征研究 总被引:1,自引:1,他引:1
相比于单极化SAR图像,全极化SAR图像不仅能体现海面目标的几何特征、后向散射特征,还能体现目标的极化特征。因此,在溢油检测方面,极化SAR更具优势。特征提取作为溢油检测的关键步骤,直接影响到溢油检测的精度。在本文中,我们分析了全极化SAR图像中海面溢油的极化特征,如极化散射熵、平均散射角等。并提出了新的极化特征P,该特征参数能够反映海面目标电磁散射过程中布拉格散射机制和镜面散射机制的比例。为了研究极化特征溢油检测的能力,本文基于SIR-C/X-SAR和Radarsat-2全极化SAR图像开展了相关实验,并对比分析了溢油的多种极化特征。实验结果显示,在中低风速情况下,C波段溢油探测效果优于L波段;本文提出的极化特征P对海面散射机制敏感;基准高度和特征参数P在C波段比其他极化特征更适于溢油检测。 相似文献
3.
4.
为提高海上溢油轮廓SAR提取精度,验证了FCM(Fuzzy C-Means Algorithm)与DRLSE(Distance Regularized Level Set Evolution)模型结合的方法提取SAR溢油信息的有效性;鉴于其无法避免细小噪音的影响以及薄油膜提取效果不好的问题,提出了阈值和DRLSE模型结合的溢油信息提取方法,通过阈值构建溢油区域初始轮廓,克服了图像细小噪声对溢油提取的影响,更有利于提取薄油膜信息,溢油提取精度优于H/A/alpha-Wishart非监督分类方法和FCM与DRLSE模型结合的方法。 相似文献
5.
海洋溢油对海洋生态和人类生活带来严重的影响。由于合成孔径雷达(Synthetic Aperture Radar,SAR)具有全天时全天候的工作能力,在海洋溢油检测中发挥重要作用。目前,极化SAR是SAR探测技术的先进手段。本文利用6个极化特征进行溢油检测,通过对比分析这些特征对不同溢油的检测能力,得出单一极化特征在溢油检测中存在不足。通过J-M特征优选方法,提取出溢油检测识别度较高的特征影像,并利用遗传算法优化的小波神经网络(Genetic Algorithm-Wavelet Neural Network,GA-WNN)进行溢油检测。利用2套Radarsat-2全极化数据进行了方法验证,结果表明,该方法优于其他检测方法,溢油检测精度分别达到90.31%和95.42%。 相似文献
6.
The SAR(Synthetic Aperture Radar) has the capabilities for all-weather day and night use. In the case of determining the effects of oil spill dumping, the oil spills areas are shown as dark spots in the SAR images.Therefore, using SAR data to detect oil spills is becoming progressively popular in operational monitoring, which is useful for oceanic environmental protection and hazard reduction. Research has been conducted on the polarization decomposition and scattering characteristics of oil spills from a scattering matrix using allpolarization of the SAR data, calculation of the polarization parameters, and utilization of the CPD(Co-polarized Phase Difference) of the oil and the sea, in order to extract the oil spill information. This method proves to be effective by combining polarization parameters with the characteristics of oil spill. The results show that when using Bragg, the oil spill backscattering machine with Enopy and a mean scatter α parameter. The oil spill can be successfully identified. However, the parameter mechanism of the oil spill remains unclear. The use of CPD can easily extract oil spill information from the ocean, and the polarization research provides a base for oil spill remote sensing detection. 相似文献
7.
8.
针对海洋表面SAR影像的特点,采用基于灰度共生矩阵的纹理特征方法是提取海面溢油信息的常用方法,但实际海洋表面复杂的信息使得SAR图像上产生类似溢油现象的暗斑区域,这导致在利用纹理特征方法提取溢油信息时存在虚警率,降低了溢油信息的提取精度。基于RADARSAT-2 SAR四极化影像,本文提出基于SAR极化比影像的纹理特征识别方法对海面油膜进行识别提取。结果显示,基于SAR极化比影像的纹理特征识别方法可以有效且准确地提取海面溢油信息,相比于VV极化影像的纹理特征识别方法,溢油监测过程中的虚警率降低了17.96%,溢油监测总体精度达到96.83%。 相似文献
9.
10.
雷达波段对多极化SAR海面溢油检测极化特征参数的影响 总被引:1,自引:1,他引:0
多极化SAR数据海面溢油检测研究日益受到重视。本文研究不同波段极化SAR数据的海面溢油检测能力,为最大程度减小观测条件、环境因素等的影响,选取准同步获取的SIR-C/X多极化SAR数据。针对海面油膜、生物油膜和低风区疑似溢油现象,研究L波段和C波段的共极化相位差、一致性系数、极化熵、各向异性和平均散射角等极化特征对海面油膜以及不同海面暗斑现象的检测能力。研究结果表明:在海面溢油检测以及探测不同暗斑现象间差异方面,C波段总体优于L波段;L波段,极化分解特征各向异性参数优于共极化相位差和一致性系数;C波段,共极化相位差、一致性系数特征优于极化分解特征各向异性和极化熵,结合平均散射角特征有助于滤除生物油膜和低风区。 相似文献
11.
Polarimetric synthetic aperture radar(SAR) oil spill detection parameters conformity coefficient(μ), Muller matrix parameters(|C|, B_0), the eigenvalues of simplified coherency matrix(λ_(nos)) and the influence of SAR observing parameters, ocean environment and noise level are investigated. Radarsat-2 data are used to make systematic analysis of polarimetric parameters for different incidences, wind speeds, noise levels and the ocean phenomena(oil slick and look likes). The influence of the SAR observing parameters, the ocean environment and the noise level on the typical polarimetric SAR parameter conformity coefficient has been analyzed. The results indicate that conformity coefficient cannot be simply used for oil spill detection, which represents the image signal to the noise level to some extent. When the signals are below the noise level for the oil slick and the look likes, the conformity coefficients are negative; while the signals above the noise level corresponds to positive conformity coefficients. For dark patches(low wind and biogenic slick) with the signal below the noise,polarization features such as conformity coefficient cannot separate them with oil slick. For the signal above the noise, the oil slick, the look likes(low wind and biogenic slick) and clean sea all have positive conformity coefficients, among which, the oil slick has the smallest conformity coefficient, the look likes the second, and the clean sea the largest value. For polarimetric SAR data oil spill detection, the noise plays a significant role. So the polarimetric SAR data oil spill detection should be carried out on the basis of noise consideration. 相似文献
12.
SAR(synthetic aperture radar)图像溢油暗斑准确识别对海上溢油应急工作具有重要的意义。为减少SAR图像特征提取、特征选择过程中人为因素对溢油检测精度的影响,本文将Faster R-CNN卷积神经网络模型引入SAR图像溢油检测并进行了改进。针对溢油暗斑形状多样及SAR图像背景复杂的特点,选用结构一致且实用性强的VGG16卷积网络获取图像特征,并使用软化非极大值抑制算法(Soft-NMS)进行优化。同时基于相同的数据集,提取常用的SAR图像几何特征、灰度特征和纹理特征,构建反向传播(backpropagation,BP)人工神经网络溢油检测方法并与Faster R-CNN方法进行对比。实验结果表明,基于改进Faster-RCNN模型的溢油检测方法溢油检测率达到0.78,且溢油检测虚警率低于0.25,相比BP人工神经网络溢油检测方法样本识别率、溢油检测率分别提高了4%和5%,溢油虚警率降低了5%。 相似文献
13.
Compared to single-polarization synthetic aperture radar(SAR) data, fully polarimetric SAR data can provide more detailed information of the sea surface, which is important for applications such as shallow sea topography detection. The Gaofen-3 satellite provides abundant polarimetric SAR data for ocean research. In this paper, a shallow sea topography detection method was proposed based on fully polarimetric Gaofen-3 SAR data. This method considers swell patterns and only requires SAR data and ... 相似文献