共查询到17条相似文献，搜索用时 109 毫秒
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海底表层底质分布信息的准确获取在构建海洋基础地理数据库中发挥着重要作用。目前,多波束是实现大范围海底底质分类的有效手段之一,基于多波束测深和反向散射强度数据所派生的声学特征被广泛应用于底质分类建模。然而,随着特征维度的增加,特征空间中存在的无关和冗余特征严重影响底质分类精度。为了定量评估声学特征对底质类别的表征能力,并消除无效特征对分类结果的干扰,本文提出了基于多维度声学特征优选的海底底质分类方法。首先,结合实际底质样本的物理属性对多维特征进行排序和优选,排除冗余和无关特征。其次,分别应用支持向量机、随机森林和深度信念网络构建海底底质监督分类模型。通过利用爱尔兰海南部多波束调查数据和实地取样信息进行试验,结果表明提出方法对海底底质的总体分类精度和Kappa系数分别最高达到了86.20%和0.834,相较于主成分分析和熵指标特征选择方法有明显提高,突出了该方法在海底底质探测及制图的应用潜力。 相似文献
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济州岛南部海域海底声呐图像分析与声学底质分类 总被引：2，自引：2，他引：0
东海北部外陆架靠近济州岛南部海域,是黄海槽向冲绳海槽延伸的部分,属于黑潮分支黄海暖流的通道入口,分布着脊槽相间的海底底形,对其海底声呐图像的处理分析及声学底质分类的分析研究,有助于了解该通道海底底形表层纹理特征及沉积物分布规律。基于在济州岛南部海域获取的多波束声呐数据,应用图像处理技术和方法,对数据进行了处理,获得了海底声呐影像图,并对其表层纹理特征进行了描述和分析;同时,基于多波束反向散射强度数据,结合19组海底地质取样数据,建立研究区海底反向散射强度与沉积物粒度特征之间的统计关系模型,并以改进的学习向量量化神经网络方法,实现对海底粉砂质砂、黏土质砂以及砂-粉砂-黏土3种底质类型的快速自动分类识别。 相似文献
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针对目前海底底质分类要素单一造成的底质分类类别不够细致和底质信息获取效率低等问题,提出一种顾及声图纹理特征的海底底质分类方法,综合利用海底底质来源、地理等属性以及声图纹理特征等分类要素,进一步细化海底底质类别,解决了海底底质分类信息混淆或表达不充分等问题。实例数据分析表明,该分类方法克服了传统方法单一考虑底质粒度信息的缺点,可以真实反映海底底质的时空变化特性以及一定范围内的表面起伏特征,并且所包含的海底底质分类信息量更全面,从而可以为用户提供直接形象的海底底质信息。 相似文献
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针对现有以常规波束形成技术为基础的多波束测深算法中存在空间分辨率不足的问题,将子空间类高分辨算法MUSIC应用到国产多波束测深系统中,探索提高多波束系统空间分辨力的方法。对MUSIC算法原理进行了数学表达式推导和性能分析,并通过计算机仿真、湖上试验数据处理验证了本算法能降低回波到达角度的估计误差,有效地提高了空间方位估计精度,具有实际应用的可行性。 相似文献
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多波束声呐记录的海底后向散射片段(Snippet)数据处理成角度响应曲线和地理编码(Mosaic)图像可以
帮助识别海底底质类型和反映地貌形态,这一过程包括辐射校正、角度响应改正(AVG)和几何地理编码,但不同的多波束系统硬件在辐射校正和角度响应改正方法上存在差异且传统处理方法忽略了声呐系统本身的指向性模型随时间变化的事实。以声呐方程为基础,针对Kongsberg EM 多波束系统提出了一套完整的Snippet数据处理流程,并分析了各步骤中存在的可变性,给出了每一步的处理建议,最后将此方法应用于EM2040浅水多波束实测数据,并验证了该方法的有效性和实用性。 相似文献
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Cholwek Gary Bonde John Li Xing Richards Carl Yin Karen 《Marine Geophysical Researches》2000,21(5):409-421
To categorize spawning and nursery habitat for lake trout in Minnesota's near shore waters of Lake Superior, data was collected with a single beam echo sounder coupled with a RoxAnn bottom classification sensor. Test areas representative of the different bottom surficial substrates were sampled. The collected data consisted of acoustic signals which showed both depth and substrate type. The location of the signals was tagged in real-time with a DGPS. All data was imported into a GIS database. To better interpret the output signal from the RoxAnn, several pattern classifiers were developed by multivariate statistical method. From the data a detailed and accurate map of lake bed bathymetry and surficial substrate types was produced. This map will be of great value to fishery and other natural resource managers. 相似文献
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ABSTRACTThis paper details a new boresight calibration method for multibeam echo sounder systems This method is based on an automatic data selection algorithm, followed by a boresight least squares adjustment This method, called MIBAC (MultiBeam-IMU Boresight Automatic Calibration), takes in input overlapping survey strips following a simple line pattern over a regular slope. We first construct a boresight error observability criterion, used to select automatically the most sensitive soundings to boresight errors. From these soundings, we perform a 3D adjustment of the boresight angle, thus taking into account the coupling between angles. From a statistical analysis of the adjustment results, we derive the boresight angle precision. Numerical results obtained with four different multibeam echo sounder systems are presented and compared to those of a patch test calibration method. Finally, we demonstrate the performances of MIBAC through a standard deviation along the surface normal approach computed by principal component analysis. 相似文献
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Rosa Freitas Ana Maria Rodrigues Edward Morris Jose Lucas Perez-Llorens Victor Quintino 《Estuarine, Coastal and Shelf Science》2008,78(4):613-622
The single-beam acoustic ground discrimination system QTC View, Series V, was used in the Bay of Cadiz, Southwest Spain, for the identification and mapping of the bottom acoustic diversity. The acoustic data were obtained through two successive surveys, each conducted with one of the following echo sounder frequencies: 50 kHz and 200 kHz. The performance of each survey frequency for the identification of the sedimentary gradients was analyzed. The surveys were conducted during high tide given that the majority of the surveyed area is shallower than 5 m, although depth may occasionally reach 20 m in specific areas located in a navigation channel. The acoustic data obtained at the two different frequencies were, individually, submitted to manual clustering and a final solution consisting of three acoustic classes was reached for both datasets. However, only the geographical distribution of the acoustic classes obtained with 50 kHz echo sounder frequency was coincident with the spatial distribution of the superficial sediment groups (silty medium sand, very silty fine sand and mud), identified through multivariate analysis of the grain-size data of ground-truth sediment samples. The results obtained with the 200 kHz echo sounder frequency did not match the sedimentary gradients obtained for the area surveyed, not even the separation of muddy and sandy areas. 相似文献
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深水多波束声呐测深数据精度评估 总被引：1，自引：0，他引：1
多波束测深精度评估是水深测量质量控制的重要方面，静态精度评估与交叉测线动态精度评估能够从不同角度表征测深精度，估计测量样本的综合误差。在实际调查作业过程中，由于缺少水深真值，在进行精度估计时缺少可操作性。本文利用Kongsberg EM120型深水多波束系统的测深数据，基于某一区域的重复测量数据，应用中央波束的水深数据进行静态精度分析；通过引入网格化方法，进行动态水深精度评估分析，并通过偏差分析揭示测量样本的误差分布特征。结果表明，中央波束水深数据静态精度评估与基于网格化方法的动态精度评估具有实际可操作性，其结果能够有效估计测深的综合误差；重复测量数据的偏差分析能够有效展示误差的分布特征。 相似文献