多重分形方法在涡旋遥感信息处理提取中的应用研究

目前提取遥感影像中的涡旋信息主要用边缘探测技术,例如Canny算子和Hough算子等,然而由于涡旋信息和遥感影像本身的复杂性和模糊性,用传统的方法不能取得理想的提取结果.基于多重分形技术,利用海洋涡旋信息的物理特征时空形态的自相似性来提取涡旋,用NASA MODIS,Sea WiFS和NOAA在典型海区如边界流的卫星影像进行试验,研究结果表明,用多重分形方法获取的涡旋信息非常有利于对海洋涡旋的深刻认识和分析研究.     

Multifractal filtering method for extraction of ocean eddies from remotely sensed imagery

1 IntroductionCurrently, the ocean eddy plays an important rolein energy flowand matter exchange in ocean. The ex-traction and analysisof the oceaneddave beeninves-tigated bylots of people in pastdecades. Currentmeth-ods to deal with the ocean eddy include static and dy-namic methods. The static method is to analyze indi-rectly ocean eddies using the spatial feature distribu-tion, change, growthand decline of the watermass (Suet al., 1996; Guo et al., 1995; Guo and Ge, 1997);the dynamic meth…     

An analysis on the error structure and mechanism of soil moisture and ocean salinity remotely sensed sea surface salinity products

For the application of soil moisture and ocean salinity（SMOS） remotely sensed sea surface salinity（SSS） products,SMOS SSS global maps and error characteristics have been investigated based on quality control information.The results show that the errors of SMOS SSS products are distributed zonally,i.e.,relatively small in the tropical oceans,but much greater in the southern oceans in the Southern Hemisphere（negative bias） and along the southern,northern and some other oceanic margins（positive or negative bias）.The physical elements responsible for these errors include wind,temperature,and coastal terrain and so on.Errors in the southern oceans are due to the bias in an SSS retrieval algorithm caused by the coexisting high wind speed and low temperature; errors along the oceanic margins are due to the bias in a brightness temperature（TB） reconstruction caused by the high contrast between L-band emissivities from ice or land and from ocean; in addition,some other systematic errors are due to the bias in TB observation caused by a radio frequency interference and a radiometer receivers drift,etc.The findings will contribute to the scientific correction and appropriate application of the SMOS SSS products.     

遥感海表盐度分析产品的有效分辨率研究

针对SMOS和Aquarius海表盐度误差分析没有区分不同空间频谱信噪特征的问题,基于6种主要的遥感盐度分析产品,根据定性图像、纬向波数谱、均方根误差等指标,分析产品的有效分辨率并探讨其原因机制。研究表明:CATDS-0.25°分析产品所描述的盐度场中小尺度结构失真,其较高谱能量密度在热带海域以噪音为主,而在西边界流等海域以信号为主;BEC-L3-0.25°有着较小的均方根误差、清晰的盐度图像、显著的中尺度能量,最适于描绘中尺度(25~100 km)盐度特征;BEC-L4-0.25°被奇异谱分析方法过度平滑了盐度场;Aquarius-V2-1.00°通过局部平滑处理,在描述大尺度(＞100 km)盐度现象方面表现较好;Aquarius-CAP-1.00°通过主动-被动联合算法(CAP)减小了均方根误差,但图像中卫星轨道形态明显;CATDS-1.00°的图像形态、能量分布和误差特征与Aquarius-V2-1.00°相当。这些结论可为用户正确使用产品进行地球物理学研究提供参考。     

基于大涡模拟和局部滤波同化方法的海洋环流模式

结合最小二乘法极值原理,提出了一种基于局部谱展开的滤波同化方法,把测量数据和数值计算过程中出现的高频短波滤掉,并将高度计数据同化到了求解过程中.结果既增加了数值稳定性,又提高了数值模拟的准确性.针对在海洋环流问题中水平的流动性质和垂直的不同的特点,我们还将大涡模拟的思想和直接涡黏的思想分别应用于水平方向和垂直方向,给出的方法是一种适用于海洋环流和浅水环流问题的大涡模拟湍流模式.对热带和北太平洋一年四季非定常季风作用下环流的数值模拟表明,提出的方法非常有效,数值结果与实际相当吻合.     

Separation of ocean features from multifrequency full-polarization SAR imagery

Different ocean features usually appear in synthetic aperture radar (SAR) images simultaneously. This makes the image compli- cated and hard to understand. Because of lower signal-to-noise rate , it is much more difficult to separate different ocean features than to separate different land features. A completely novel method is presented to separate ocean features from multifrequency po- larimetric SAR imagery. AIRSAR data from Jet Propulsion Laboratory (JPL), National Aeronautics and Space Administration (NASA) are used in the case studies and good results are achieved.     

A simulation of radiation imagery for ocean color satellite

The ocean color satellite is mainly applied to measure the water constituents such as chlorophyll, suspended material and yellow substance. The leaving water radiance is very small part of the total radiance arrival at the sensor about 3%-15%,and depends on the properties of the orbit and sensor. Before the satellite is launched on the orbit, it needs to simulate the radiation imagery in order to evaluate the quality and availability of the satellite data.
If the parameters of satellite orbit, the properties of sensor as well as the characteristics of the atmosphere and water have been known, the radiation scattered by air molecule and aerosol, reflected solar radiation, water leaving and total radiation arriving at the sensor can be simulated by the models of radiation transfer in the atmosphere, air/water and subsurface water. In this paper, the mechanism, models and procedures of the radiation simulation are first discussed and employed to simulate a series of imageries for the Chinese satellites FY-lA, FY-1B, and ROCSAT-1 (Taiwan, China), and American satellite Ses STAR. Their results show that the solar irradiance arrived at water surface and the sun glitter mainly affect the quality and availability of satellite data, which depend on the orbit properties. Finally, some suggestions are proposed to improve the quality and availability of a:ean color satellite data.     

面向拓扑分析的海洋流场临界点提取算法研究

临界点是海洋流场拓扑结构中的重要构成要素,基于临界点的特征提取对于揭示海洋流场拓扑特征、开展海洋流场拓扑分析具有重要意义。本文基于临界点理论和Sperner引理,综合改进后的双线性插值算法和Sperner完全标号法,对海洋流场数据进行了临界点特征提取。首先,在双线性插值算法中添加滑动窗口处理,筛选临界点的候选网格单元,并采用聚合思想通过降低网格分辨率解决了网格插值中的二义性问题,同时考虑了0值网格存在的9种情形,通过迭代聚合思想滑动筛选候选网格单元,解决了插值网格均为0的情况。其次,提出了基于Sperner完全标号的最小值法临界点提取规则,将速度向量模最小的网格中心作为临界点,解决了实际流场物理场景中非0值的临界点提取。对两次提取结果进行合并、去重等处理,可以得到较为全面的临界点提取与分类结果。最后,通过对多个海域、不同深度流场数据的实验结果分析,证明了综合后的临界点提取方法的有效性及可行性。     

支持海洋遥感信息提取技术的可视化建模系统流程设计

根据海洋遥感信息提取可视化建模应用需求,以用户可视化模型建立及流程设计实现为目标,采用统一建模语言UML面向对象分析方法,设计海洋遥感信息提取可视化建模系统软件结构、用户需求用例(use case)结构、类(class)结构及流程图表示法,同时完成流程定义器、流程调度的设计和实现.结果表明,可视化用户建模系统可以使广大海洋用户在使用遥感数据时无须在数据预处理及转换工作上花费较多的时间,也不要学习很多遥感信息处理专业知识即可适应和使用组件式海洋遥感数据处理和信息提取通用软件,并且在该软件平台上进行他们的研究和应用开发工作.     

基于中值滤波加权修正的多波束声呐测深数据趋势面滤波方法

针对传统趋势面滤波方法中多项式拟合曲面系数向量的求取和作为阈值的均方根误差的求取都受到异常数据的影响,使该方法在异常测深数据较多的情况下滤波效果不佳的问题,提出了一种中值滤波加权修正的改进方法。在构造趋势面之前,对水深数据进行加权修正,以前后两次修正后数据的拟合优度的变化量作为是否进行下一步水深修正的依据,利用最终修正后的水深数据求取多项式拟合曲面系数向量和均方根误差,大幅降低了异常数据的影响,具有很强的抗差性。经仿真模拟数据和多波束实测数据滤波试验,该方法在异常数据较多的情况下依然良好,能够保持良好的滤波效果,明显优于传统趋势面滤波;同时,该方法能够保持较高的运算效率,适用于海量多波束测深数据的自动滤波。     

基于光流法的X波段雷达浪向反演研究

浪向代表着海浪传播方向,它是海上交通安全以及海岸资源管理的重要海洋环境参数之一。本文针对X波段测波雷达对海杂波的连续成像,提出了一种基于光流法的海浪传播方向反演新方法。该方法利用X波段测波雷达接收的海面回波图像序列直接进行光流运动估计,将得到的每个像素点的运动矢量进行加权平均,最后得到实际的海浪传播方向。与传统基于频域的X波段测波雷达浪向反演方法相比,本文提出的方法直接从时域来进行回波信号处理,无需提前得到调制传递函数以及精确的海流,减少了由于海流估算的不准确以及调制传递函数选取的误差而给雷达浪向反演带来的影响。同时,该方法简单高效,占用资源少,将其应用至仿真雷达回波以及现场实测数据来进行浪向反演,反演得到的浪向与仿真设定浪向值以及浮标实时观测浪向结果都有很好的吻合度,变化趋势也完全一致,进而验证了该方法的有效性以及准确性。     

全球海洋治理视域下海洋资源资产负债表探析

全球海洋治理背景下,以国家为主体的海洋资源资产负债表能够宣示国家海洋主权,服务海洋开发决策,监管人类海洋行为。海洋资源资产负债表按照海洋资源类型进行核算,海洋资源负债按性质分为政府负债和使用权人负债。在计量上要审慎乐观,采用实物计量和货币计量,不宜低估海洋资源资产,也不宜高估海洋资源负债。海洋资源资产负债表体系以海洋资源资产负债表为主表,海洋资源资产和负债变动表为副表,各类海洋资源明细表为子表。国家应协调好海洋资源与陆地资源核算的范围,近海资源由沿海基层政府核算上报,其他海洋资源由自然资源部统一核算,最终汇总为国家海洋资源资产负债表。     

采用射线追踪法的天然气水合物海底地震观测系统设计

射线追踪法是以建立的地下地质模型为基础,研究不同的激发点发出的射线经地下地质界面反射后可以被接收到的信息,从而了解不同的观测系统对于特定地质条件地震资料采集的效果,对于海上地震采集相关参数的确定十分关键.在天然气水合物地震勘探中,丰富的多波勘探信息对于查清水合物内部速度结构、提高地层的分辨率具有重要意义.本文在分析国外天然气水合物海底地震仪(OBS,ocean bottom seismometer)勘探的应用成果基础上,采用射线追踪法理论计算和海上实验,实现了针对天然气水合物的海底地震观测系统设计,试验获得了转换横波记录,取得了良好的应用效果.     

利用浅水地形及其SAR影像确定海面风向的一种方法

利用浅水地形的SAR影像以及基于浅水地形SAR仿真模型计算得到的仿真SAR影像,基于仿真SAR影像与真实SAR影像之间的相关性提出了一种确定海面风向的方法——最大相关系数法.以南沙双子礁海域为例,利用最大相关系数法确定出了一幅RADARSAT SAR影像成像时刻的海面风向,通过对结果的比较分析可以看出对于包含浅水地形的SAR影像应用该方法探测海面风向是可行的.     

龙须菜琼胶的提取方法研究

采用多种方法提取了龙须菜(Gracilaria lemaneiformis)中的琼胶,并研究了碱处理、微波处理、超声波处理等方法对龙须菜的琼胶提取率、硫酸基质量分数和多糖质量分数的影响。结果表明:当碱质量分数由2.5%增加到10%时,琼胶产率由15%降低到9.8%,硫酸基质量分数由2.66%降低到2.06%,同时,多糖质量分数由98.3%增加到102.6%;微波和超声波处理在不同程度上增加了琼胶的提取率和多糖质量分数,同时降低了硫酸基质量分数。另外,还从宏观和微观两个角度考察了龙须菜碱处理前后藻体的变化。     

Scaling of motion and governing equations for baroclinic large-scale motions in equatorial ocean

PROPOSALOFPROBLEMTheequatorialoceanicdynamicsintightconnectionwiththeEINinoeventshasbeenthefocusoftheoceanographer'sattention.Asabasisofequatorialoceanicdynamics,theconventionaltheoryoftheequatoriallytrappedwaves,whichwerefertothetrappedwavetheoryinextensiveliteratureuptodate(Matsuno,1966;Blandford,1966;MunkandMoors,1968;WunschandGill,1976;MoorsandPhilandet,1977;Eriksen,1985;Pedlosky,1987),hasbeenprogressivelydevelopedandemployed.However,thedetailedinvestigationsrevealthattheproper…     

Improved dithiocarbamate/oxine solvent extraction method for the preconcentration of trace metals from seawater using metal exchange back-extraction

A rapid single extraction procedure using dithiocarbamate complexing agent, a di-isobutyl ketone (DIBK) organic phase and Hg exchange back-extraction is described for the simultaneous quantitative preconcentration of Cd, Co, Cu, Fe, Ni, Pb and Zn in seawater. An 8-hydroxyquinoline (oxine) extraction technique is also presented for the subsequent determination of Mn using the same reagents and operating system. The proposed method gave quantitative spike recoveries for all metals and was in excellent agreement with the certified results for CASS-3 marine reference seawater. Blanks and detection limits are in the low ppt range. The method gives a preconcentration factor of 72 for an 80-ml sample, facilitating the analysis of pristine seawater samples.     

利用监督分类快速提取分层设色图件中数据的方法

为了快速将分层设色图件中象元的颜色值转化为具有实际意义的属性标识或物理、化学参数值,从而提取分层设色图件中包含的数据,作者提出了根据不同颜色分量(RGB)构建颜色特征空间,基于最小距离监督分类方法快速提取分层设色图件中数据的方法。使用该方法对东半球海域海面水汽分布数据进行提取,取得了良好的效果。该方法可以广泛应用于物理海洋、环境科学、地质调查、地理信息系统建库等多个行业领域的数据提取工作中。     

Species richness of the genus Molgolaimus (Nematoda) from local to ocean scale along continental slopes

This study investigated the distribution of Molgolaimus species (Nematoda) at different hierarchical spatial scales and observed the turnover of species along bathymetrical transects and among transects in two separate geographical regions. Samples from six transects (200–2000 m) from the Southern Oceans (SO) and four bathymetric transects (50–2000 m) from the Western Indian Ocean (WIO) were compared. Of the 30 species recorded, only one was common to both regions. WIO had higher local species richness than the SO. In both regions, the local scale was the greatest contributor to the total species richness. In the SO, there was no difference between species turnover at the different spatial scales, however, in the WIO, the turnover along bathymetrical transects was higher than among separated transects. For the particular genus studied, the evidence suggests that the study area in WIO has more widespread species and was better sampled, while the SO has many restricted species and it is most probably characterized by different biogeographical provinces. At the ocean scale (i.e. WIO versus SO), evolutionary histories may have strongly influenced nematodes species composition, while at local and regional scales, ecological processes are probably promoting species co‐existence and speciation. The high co‐existence of certain species at local scale is partially explained by species preference for different sediment layers.