Accuracy and precision of fish-count data from a "dual-frequency identification sonar" (DIDSON) imaging system     

Holmes  John A.; Cronkite  George M.W.; Enzenhofer  Hermann J.; Mulligan  Timothy J. 《ICES Journal of Marine Science》2006,63(3):543-555

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Estimation of gillnet and hook selectivity using log-linear models   总被引：5，自引：0，他引：5  

Millar  Russell B.; Holst  Rene 《ICES Journal of Marine Science》1997,54(3):471-477

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基于GIS的无人机地面监控系统的设计与实现   总被引：3，自引：0，他引：3  

熊自明  葛文 《海洋测绘》2007,27(4):54-56

在分析无人机领域飞行数据特征的基础上,设计实现了一套功能较为完善的无人机地面监控系统。该系统主要完成了无人机飞行状态实时显示、航线规划和航线回放等功能模块。系统借助于G IS技术,导入矢量形式的电子地图,利用丰富的地理信息来辅助实现无人机的地面监控,在V isual C 6.0开发环境下利用基于异步方式和事件驱动方式的串口通信实现了系统与地面控制站的通信,利用地图控制文件实现了地图数据的调度,利用显示缓存实现了视图实时刷新。经过实际联调,系统运行良好,实用性较好。  相似文献   

Validation and Improvement of Satellite-Derived Surface Solar Radiation over the Northwestern Pacific Ocean     

Kawai  Yoshimi  Kawamura  Hiroshi 《Journal of Oceanography》2005,61(1):79-89

The purpose of this study is to validate and improve satellite-derived downward surface shortwave radiation (DSSR) over the northwestern Pacific Ocean using abundant in situ data. The DSSR derivation model used here assumes that the reduction of solar radiation by clouds is proportional to the product of satellite-measured albedo and a cloud attenuation coefficient. DSSR is calculated from Geostationary Meteorological Satellite-5/Visible Infrared Spin-Scan Radiometer data in 0.05° × 0.05° grids. The authors first compare the satellite DSSR derived with a cloud attenuation coefficient table determined in past research with in situ values. Although the hourly satellite DSSR agrees well with land in situ values in Japan, it has a bias of +13∼+34 W/m² over the ocean and the bias is especially large in the low latitudes. The authors then improve the coefficient table using the ocean in situ data. Usage of the new table successfully reduces the bias of the satellite DSSR over the ocean. The cloud attenuation coefficient for low-albedo cases over the ocean needs to be larger in the low latitudes than past research has indicated. Daily and hourly DSSR can be evaluated from the satellite data with RMS errors of 11–14% and 30–33%, respectively, over a wide region of the ocean by this model. It is also shown that the cloud attenuation coefficient over land needs to be smaller than over the ocean because the effect of the radiation reflected by the land surface cannot be ignored.  相似文献   

GPS数据采集技术及其在海洋调查中的应用   总被引：1，自引：0，他引：1  

邱雨生  陈敏  刘广山 《台湾海峡》2003,22(3):354-359

本文应用VB6．0开发了智能化的GPS数据采集软件．对该软件的功能进行了简单的介绍，同时对一些关键技术作了较详细的描述。利用该软件、GPS接收机及PC机的组合，可对走航式测量仪器(或移动设备)进行实时定位并保存定位记录，且大大减少一些不必要的数据，使得软件更为实用。  相似文献   

TSDV: A GIS tool for inspecting trawl survey data     

Fortunati  L.; Garofalo  G.; Demontis  R. 《ICES Journal of Marine Science》2002,59(1):168-178

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A New Methodology for Incorporating Tide Gauge Data in Sea Surface Topography Models   总被引：1，自引：0，他引：1  

J. C. Iliffe  M. K. Ziebart  J. F. Turner 《Marine Geodesy》2007,30(4):271-296

As part of the Vertical Offshore Reference Frames (VORF) project sponsored by the U. K. Hydrographic Office, a new model for Sea Surface Topography (SST) around the British Isles has been developed. For offshore areas (greater than 30 km from the coast), this model is largely derived from satellite altimetry. However, its accuracy and level of detail have been enhanced in coastal areas by the inclusion of not only the 60 PSMSL tide gauges with long-term records around the coasts of the United Kingdom and Ireland but also some 385 gauges established at different epochs and for different observation spans by the U. K. Admiralty. All tide gauge data were brought into a common reference frame by a combination of datum models and direct GPS observations, but a more significant challenge was to bring all short-term sea level observations to an unbiased value at a common epoch. This was achieved through developing a spatial-temporal correlation model for the variations in mean sea level around the British Isles, which in turn meant that gauges with long-term observation spans could be used as control points to improve the accuracy of Admiralty gauges. It is demonstrated that the latter can contribute point observations of mean sea level (MSL) with a precision of 0.078 m. A combination of least squares collocation and interpolation was developed to merge the coastal point and offshore gridded data sets, with particular algorithms having to be developed for different configurations of coastal topology. The resulting model of sea surface topography is shown to present a smooth transition from inshore coastal areas to offshore zones. Further benefits of the techniques developed include an enhanced methodology for detecting datum discontinuities at permanent tide gauges.  相似文献   

Unintended and perverse consequences of ignoring linkages in fisheries systems     

Degnbol  Poul; McCay  Bonnie J. 《ICES Journal of Marine Science》2007,64(4):793-797

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On the geologic structure of the Explora Escarpment (Weddell Sea,Antarctica) revealed by satellite and Shipboard data evaluation     

Ute Christina Herzfeld  Arnold L. Brodscholl 《Marine Geophysical Researches》1994,16(5):325-345

Bathymetric, gravity, and magnetic data from Antarctic expeditions with RV POLARSTERN and satellite altimeter data from the Geosat Geodetic Mission are analysed using methods from geostatistics and geophysical inverse theory.The Explora Escarpment represents the edge between the Antarctic Continental Shelf and the Weddell Abyssal Plain. It is an important link in the reconstruction of Gondwana breakup, but a feature as large as the 2000 m deep Wegener Canyon was only discovered in 1984, when extensive bathymetric, gravimetric, and magnetic surveys with RV POLARSTERN began.Geostatistics, the theory of regionalized variables, is applied to integrate dense surveys of Wegener Canyon and sparse observations in adjacent areas into maps with full coverage of the 230 km by 330 km area at 10°–20° W/70°–72° S. The resultant highresolution bathymetric and gravity maps reveal detailed structures of the Explora Escarpment. Using geophysical inversion, the gravity terrain effect is calculated. Satellite data are used for their better coverage, but have much lower resolution. Nevertheless, the structures of Wegener Canyon and other more prominent features appear with surprisingly good correlation also in the Geosat altimeter data. While it was initially supposed that Wegener Canyon is purely an erosional structure, the magnetic map now provides evidence of the canyon's tectonic origin.  相似文献   

Modelling morphological processes in the vicinity of shore-parallel breakwaters     

Julio A. Zyserman  Hakeem K. Johnson 《Coastal Engineering》2002,45(3-4)

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