一种无人机影像点云提取海岛自然岸线的方法

针对从机载激光点云中提取海岸线方法的不足,提出了一种基于无人机影像DSM点云数据,结合潮汐模型提取海岛自然岸线的方法。采用计算机视觉理论与方法处理高分辨率无人机影像,获取高分辨、高精度的DSM点云,并由DSM点云生成DEM;通过等值线追踪法自动提取基于平均大潮高潮面的海岛岸线。实验结果表明:该方法提取的海岛自然岸线精度满足海道测量规范相关要求。     

多源水深数据融合的近海数字水深模型构建

针对近海多源水深数据来源复杂,密度不均匀的特点,提出了构建近海数字水深模型的方法。首先选择合适的插值方法建立多分辨率的数字水深模型,然后采用叠加融合多分辨率网格的方法建立最终的高分辨率数字水深模型。以渤海海区的部分多波束、单波束数据为例,分别采用克里金法、连续曲率张力样条法和狄洛尼三角网法三种插值方法,结合模型融合建立高分辨率数字水深模型,评价了3种插值方法建立数字水深模型的精度,分析了影响数字水深模型建立的因素,并给出了多源数据构建数字水深模型的插值方法选取的合理化建议,以最大程度保证数字水深模型的精度,对我国目前近海的数字水深模型的建立具有实际应用价值。     

国际海道测量标准比较研究

为适应海道测量数据应用领域不断扩大和用户要求不断提高的需求,国际海道测量组织和世界海道测量技术发达国家相继发布了各自的新版海道测量规范和标准.将我国海道测量规范与国际海道测量标准在测量的分类与质量基准、水深测量技术要求以及其他测量标准等方面进行比较详细的分析比较,指出了我国海道测量规范的不足和需要改进的问题,旨在推进我...     

水深源数据不确定度在TIN水深建模中的传播规律分析

在确定水深源数据的水平和垂直不确定度的基础上,分析了水深源数据不确定度在三角网水深建模过程中的传递机制,推导了水深源数据不确定度对水深模型影响的公式。通过理论分析可得:水深源数据水平不确定度的传播会受区域内水深变化的影响,即区域水深变化越大,其对水深模型不确定度的影响就越大;水深源数据垂直不确定度的传播不受其他因素影响,其会直接传递到水深模型表面的各点上。     

基于多源数据融合的典型海岛三维形貌表征方法研究

随着海岛开发利用和基础设施建设的频繁,高效、精准地获取海岛形态基础数据就显得尤为迫切。三维地形地貌探测和构建技术的日臻完善,及时解决了海岛基础勘测时间长、效率低、精度小的问题。文章通过三维激光扫描和无人机航测手段,全覆盖扫描广西小庙墩(炮台口)海岛表面形态,结合RTK-DGPS实测验证和近景摄影测量,获取海岛实景,运用Geomagic Studio和Smart3D等软件,构建典型海岛三维数字高程模型(DEM),融合多源数据和海岛实景,还原海岛高精度仿真三维形态。为高精度勘测海岛提供有效手段,为海岛基础地理信息获取、地质灾害识别和生态环境修复提供基础数据支撑。     

风浪对众包测深数据的精度影响分析

针对当前众包测深数据精度难以掌控导致其难以应用的现状,通过构建船舶横摇姿态计算模型,分析了风浪这一重要海洋环境因素对众包测深数据精度的影响程度,得出了众包测深数据的推荐风浪条件和最低要求风浪条件。实验结果表明:①风浪等级增大,各测深点水深测量偏差随之加大,符合《海道测量规范》测深限差要求的测深点数量也随之减少,且在海底倾斜越严重的海域,表现更加明显;②3级风2级浪条件下的众包测深数据可满足限差要求;4级风3级浪时众包测深数据在不同海底倾斜程度下,满足限差要求的数据量不一样;5级以上风4级以上浪在海底倾斜程度超过7.5°时多数测深点不能满足限差要求。     

航空摄影测量技术在海岛礁测绘的应用

在完成海岛像控测量、野外调绘、空三加密、内业测图等航空摄影测量技术流程,测绘比例尺1:10000海岛地形图,制作相应的数字高程模型、正射影像图等产品的基础上,总结了航测技术应用于海岸、海岛地形测绘的技术方法、作业流程,并将航测成果与常规海岸地形测量成果进行比对,得出了航测成果精度能够满足<海道测量规范>要求,航测技术可...     

基于不同水位观测时长下的深度基准面精度分析

深度基准面是海图水深的起算面,其精度直接影响着真实水深的精度.《海道测量规范》中对深度基准的求解方法进行了规定,但是未对其求解精度进行要求.因此本文采用我国10个验潮站19a间水位观测数据,分析了各站点不同水位观测时长求解的平均海面精度和深度基准精度,实验结果表明,对于港航区域重要长期验潮站,海图深度基准的设定应该采用...     

海岛礁磁偏角测量原理与方法

如何在海岛礁上进行地磁测量是当前海洋测量领域面临的技术难题。基于较为成熟的陆上流动地磁测量模式,结合海岛礁磁偏角测量的特殊性,提出了较完整的海岛礁磁偏角测量技术流程,包括工作原理、测量仪器、数据采集和处理过程、指标要求等关键环节,初步构建了海岛礁地磁测量技术基础框架。     

基于RTK的测量艇实时姿态模型研究及应用

当前,小艇挂载单波束测深系统实施水深测量时,易受风、流、涌浪等复杂因素影响,导致水深测量精度偏低。为了探究船体姿态对水深测量数据精度影响机理,提升单波束水深测量精度,基于RTK实时测定船体三点的高程,结合小艇姿态改正模型,确定小艇实时姿态、航向、换能器动态吃水及升沉,重算深度及位置。通过在珠江口某海域设置不同姿态场景实测数据,计算实时小艇姿态等数据,分析不同船姿态对测深精度的影响规律,重算了水深及位置数据,有效地提高了单波束水深数据精度。     

Model of the post-Cenozoic evolution of the cryolithozone of the shelf of the western part of the Laptev Sea

The analysis of the structure of the cryolithozone, facies, and thicknesses of the Quaternary sediments and the results of the physicochemical mathematical modeling of the modern shelf of the western part of the Laptev Sea support the influence of the Late Pleistocene glaciations on the heat conditions and the distribution of the permafrost in the area. A ～200-m thick glacier formed under aerial conditions from atmospheric precipitation represented the metamorphosed snow cover. According to the modeling, the long-living (from 60?50 to 10?4 ky) glacier reduced the thickness of the permafrost rocks in the reviewed shelf area for 280–360 m. The Holocene marine transgression additionally decreased the thickness from 50–140 m on the inner shelf to 220–350 m on the outer shelf. The modern submarine cryolithozone 450-0 m thick is wide-spread in the studied region from the coast to the shelf boundary (isobaths of 130–140 m), where it pinches out at a distance of ～380 km from the coast at a depth of ～250 m above the sea level.     

Investigation of the mechanism of the long-term evolution of the carbon cycle in the ecosystem of the Sevastopol bay

We analyze the components of the carbon system of the Sevastopol bay waters and the balance of main sediment-forming substances using the data of field investigations in 1998–2008. The interannual variations of total inorganic carbon and the equilibrium partial pressure of carbon dioxide in the bay water are noted. An increase in the flux of carbon dioxide into the bay and in the content of organic carbon in bottom sediments is revealed, and an explanation of this phenomenon is given. The priority accumulation of organic carbon in the sediments of the bay is established. We assess the interannual variation in the relative abundances of organic and inorganic carbon as an index of the carbon cycle stability.     

Contemporary state of the investigation of the influence of the discharge of rivers on the hydrologic structure of the Black Sea

We generalize and analyze the state of investigations of the influence of river waters on the hydrologic structure of the Black Sea. Specific features of the water, regime and hydrography of rivers flowing into the sea, data on the discharge of rivers, and intrayear and interyear variability of the discharge are presented. We discuss and analyze works studying the transformation of river waters, routes of desalinized sea waters, and their influence on the thermohaline structure and dynamic regime of the sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Modelling of the ecosystem of the Black-Sea shelf zone near the estuary of the Danube

We analyze the results of numerical calculations performed according to the three-dimensional interdisciplinary model of an ecological system of the Black-Sea shelf zone near the estuary of the Danube. The complete system of equations of hydrothermodynamics is solved together with transport equations of the advection-diffusion-reaction type used to describe the transformation of a substance (nitrogen) between the components of the characteristic vectors of the ecosystem: plankton, detritus, and biogenic elements (nitrates). We describe the distinctive features of the circumcontinental distribution of components obtained as a result of numerical experiments and present arguments for the conclusion that the ecosystem of the Danube estuary water area plays the role of a buffer zone between the press of the Danubian biogenic pollutions and the neighbouring areas of the shelf zone and open sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

Relationship between the path of the Kuroshio in the south of Japan and the path of the Kuroshio Extension in the east

A relationship between paths of the Kuroshio and Kuroshio Extension (KE) is investigated, using the satellite-derived altimetry dataset of 1993–2008. When the Kuroshio takes the nearshore nonlarge meander path or typical large meander path and resultantly goes through the deeper channel (about 2500 m) of the Izu-Ogasawara Ridge, the KE path adopts a relatively stable state with the two quasi-stationary meanders. On the other hand, when the Kuroshio takes the offshore nonlarge meander path and then passes over the shallower part of the Ridge (about 1000 m), the KE path tends to be convoluted, i.e., an unstable state.     

Dynamics of the ice cover and peculiarities of the ice transportation of the sediments at the tidal flats of the Kandalaksha Gulf of the White Sea

Ten years of semistationary studies of the interaction of the ice cover and the coastal relief of the Kandalakhsa Gulf in the White Sea allowed us to reveal the peculiarities of these processes in the warm and cold years and the mechanisms of the origination of ice forms, including ice tents, which govern the character of the tidal flats. Three dynamic fast ice zones are distinguished by their geomorphological location, morphology, and ice dynamics. The dependence of the mechanisms and volumes of the enrichment of the fast ice in the sediments on the coastal zone??s relief was established. At the coast of the Kindo Peninsula (Velikaya Salma Strait), the ice mostly contains fine-sandy sediments. Coarser sediments, including boulders, are occasional and frozen into the ice at the contact of the fast ice and the bottom. At the expense of the ice??s spreading by 4?C6 times in the warm years and 2?C4 times in the cold years, several thousand tons of sediments mostly from the tidal flat??s surface (100?C700 m³ from 1 km of coast in the wide tidal flats and <50 m³ on the steep coasts) are delivered to the water area.     

Parameters of the sediments of the deep-water basin of the Black Sea

The methodology and the first results of the computations of the volumes, masses, and growth rates of the sedimentary body of the buried Black Sea basin are presented. Their temporal evolution reflects the regional paleogeodynamics, in particular, the reorientation of the vector of the relative movement of the Arabian and Eurasian lithospheric plates and the related intensification of their collision in the late Miocene-Pliocene.     

Variability of the nutrient runoff of the rivers of the Arctic Basin

The spatiotemporal variability of the hydrochemical composition of the riverine runoff in nearmouth areas is presented using the example of selected rivers of the Arctic Basin. The temporal dynamics of the riverine nutrient runoff are mainly determined by the seasonal and interseasonal variations in the drainage basins. The spatial variations in the chemical composition of riverine waters in the near-mouth areas are mainly caused by the dynamics of the water flow and the river bed relief and, to a lesser degree, by biochemical processes. It is shown that the variations in the nutrient composition of the waters in near-mouth areas are comparable in magnitude to those at the river-sea geochemical barriers.     

A model of the dynamics of the ecosystem of the Sea of Azov

We use many-year archival observations of hydrologic and hydrobiologic state of the Sea of Azov for the identification of the structure of a model of its ecosystem. The ecosystem model, supplemented with expert estimates of bioresource consumption (fish reserve), contamination level, and possible ecologic fines for violation of the sea natural state, is formalized by the method of system dynamics. Hereat, the major part of influence functions is found in terms of observational data with application of self-organization algorithms. We also present the results of simulated experiments with the model of the ecosystem, which enable us to analyse scenarios of its behaviour under the influence of various external factors (wind, river discharge, water exchange with the Black Sea, etc.). Translated by Peter V. Malyshev and Dmitry V. Malyshev     

On the Relationship between the Characteristics of the Annual Variations of the Virtual Height of the Ionospheric Sporadic E Layer with the Seasonal Rearrangements of the Stratomesospheric Circulation

Izvestiya, Atmospheric and Oceanic Physics - Analysis of the temporal variations of the virtual heights of the sporadic E layer (h?ES) determined from ionograms with increased accuracy (1...