OCEANS '02 MTS/IEEE最新文献_第4页

Global river inflow with Navy Coastal Ocean Model 海军沿海海洋模型的全球河流流入

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1191855

C. Barron, L. Smedstad

{"title":"Global river inflow with Navy Coastal Ocean Model","authors":"C. Barron, L. Smedstad","doi":"10.1109/OCEANS.2002.1191855","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1191855","url":null,"abstract":"One of the primary concerns driving the development of U.S. Navy global models has been improved performance and nesting support in shelf and nearshore regions with short notice applicability anywhere on the globe. A global implementation of the Navy Coastal Ocean Model (NCOM) is a product of some of the efforts to meet this need. One purpose of Global NCOM is to provide a global capability for initializing, nesting, and evaluating fixed and relocatable coastal ocean models. In support of that objective, a database of river flow estimates is needed. Perry et al. (1996) provides a start with estimates of annual mean river discharges for 981 of the largest global rivers. However, many rivers exhibit a strong seasonal variability, which we would like to reflect in our ocean models. Through the use of multiple Internet sources and published data sets we have expanded on the Perry (1996) data to provide a global database of monthly mean river discharge and incorporated this data in global and nested NCOM runs. Where sufficient data is unavailable to construct monthly means, a seasonal cycle is imputed from nearby rivers and scaled to the appropriate annual mean. Real time discharge rates are routinely available for almost no rivers outside of the United States, so a monthly mean is likely to be the most appropriate estimate of real time flow for analyses and forecasts in most areas. The monthly river outflow can contribute to more accurate seasonal representation of areas near coastlines. Seasonality particularly affects the polar areas, where river outflow can become quite small during winter months and quite large during the summer melting season. Multiannual daily USGS observations for selected US rivers are used to quantify the improvement in estimation of daily flow by the monthly means versus a multiannual mean. Case studies examine the impact of river input into NCOM.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133141148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

A stereo imaging framework in 3-D mapping of benthic habitats and seafloor structures 三维底栖生物栖息地和海底结构的立体成像框架

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1191914

S. Negahdaripour, H. Madjidi

引用次数: 1

Propagation of signals in the water column: measurements and modelling 水柱中信号的传播:测量和建模

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1192015

D. Phelps, S. Dugelay

引用次数: 0

Integrating ocean acoustic propagation models and marine mammal auditory models 结合海洋声传播模型和海洋哺乳动物听觉模型

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1192117

H. Shyu, R. Hillson

{"title":"Integrating ocean acoustic propagation models and marine mammal auditory models","authors":"H. Shyu, R. Hillson","doi":"10.1109/OCEANS.2002.1192117","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192117","url":null,"abstract":"In responding to concerns about the potential impact of active sonar systems on marine mammals, the US Navy has initiated a research and development program to study the effects of sound on the marine environment (EMSE). As part of the ESME effort, the Naval Research Laboratory is developing a workbench for integrating the diverse software modules under development by other ESME researchers. This workbench models the complete sound propagation path: from the source, through the medium, and to the biosensor system. It allows researchers to explore different scenarios for the interaction between sonar, the marine environment, and marine mammals. There are several issues in building such a workbench. First, the Temporary Threshold Shift (TTS) data for marine mammals are very limited. Both behavioral and physiological models for estimating the TTS for marine mammals as a function of auditory exposure are still in their early stages of development. Second, developing an ocean acoustic propagation model that can produce accurate sound field estimations in shallow water environments is still a challenge. Third, collecting accurate oceanographic data directly such as sound speed profiles, sea floor properties, and bathymetric data is very expensive. The accuracy of oceanographic data directly affects the outcome of an ocean acoustics propagation model. As more and more experimental data are collected, the TTS estimation models for marine mammal auditory systems and the ocean acoustic propagation models will both improve. Furthermore, the Navy has an ongoing effort to collect more accurate oceanographic data. To build a software system that can incorporate software components subject to modification, the components should be modular. Modular components may be easily replaced by improved components provided that the interfaces are clearly defined and stable. This paper describes the current state of this software workbench development effort and discusses the issues involved in integrating different software models developed independently for modeling different phenomena.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115239852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Processing of forward scattered acoustic fields with intensity sensors 用强度传感器处理正向散射声场

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1191924

B. Rapids, G. Lauchle

{"title":"Processing of forward scattered acoustic fields with intensity sensors","authors":"B. Rapids, G. Lauchle","doi":"10.1109/OCEANS.2002.1191924","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1191924","url":null,"abstract":"In bistatic scattering geometries, the detection of a signal scattered in the forward direction by a stationary object can be difficult because the incident and scattered waves combine into a simultaneous mixture. Reverberation can complicate the measurements even further. At opposite ends of the forward scattering phenomenon are the Rayleigh scattering region, where the scattered wave is masked by the incident wave; and the geometrical optics region, where the two wavefields interfere to form an acoustic shadow. Pressure sensors can only provide an estimate of the magnitude of the intensity associated with an equivalent plane wave field, while true intensity sensors measure simultaneously the acoustic pressure and particle velocity components (or a related quantity such as acceleration, displacement, or pressure gradient) at a single \"point\" in space. The coherent measurement of both acoustic field parameters provides not only the magnitude of acoustic intensity but the phase between acoustic pressure and velocity. It is hypothesized that processing methods could be developed which exploit the relationship between these types of coherent measurements in order to extract information regarding the presence and nature of an object residing on or very close to the bistatic baseline. In this paper, this hypothesis is explored computationally using a rigid prolate spheroid as a canonical scattering body.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115891204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

SAS imaging of proud and buried targets at search frequencies SAS成像的骄傲和埋藏目标在搜索频率

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1191985

S. K. Mitchell, S. P. Pitt

引用次数: 3

An operational forecast modeling system for the Mississippi Sound/Bight 密西西比声/光的业务预报建模系统

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1192074

A. Blumberg, Q. Ahsan, Honghai Li, J. Blaha

{"title":"An operational forecast modeling system for the Mississippi Sound/Bight","authors":"A. Blumberg, Q. Ahsan, Honghai Li, J. Blaha","doi":"10.1109/OCEANS.2002.1192074","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192074","url":null,"abstract":"An operational forecast modeling system for the Mississippi (MS) Sound/Bight has been developed. The system integrates a triple nested coastal ocean forecast modeling systems and a meteorological forecast model. The Mississippi Sound/Bight model based on ECOMSED, forms the central core of the operational forecast system. At its eastern and southern boundaries, the ECOMSED is coupled to a regional Gulf of Mexico (GOM) model in a manner that ensures seamless energy transfer between the two models. Meteorological forcing is provided by the Coupled Ocean/Atmospheric Mesoscale Prediction System, COAMPS. The forecast system automatically retrieves all available real-time river discharge data along the Gulf coast to be imposed as coastal boundary conditions. The operational MS Sound/Bight forecast model produces two 12-hour hindcast and two 48-hour forecasts everyday at 0000 and 1200 hours. The system is scheduled to run for 12 hours in a hindcast mode and then 48 hours in a forecast mode. However, these simulation periods can vary. Depending on the availability and lengths of inputs from the coupled GOM and COAMPS models, the operational system automatically sets the periods for hindcast and forecast simulations. The model saves the proper hydrodynamic information for a restart so that a smooth and seamless execution is possible to start the next cycle. All of the simulations of the model are performed and archived on the Major Shared Resource Center (MSRC) high-performance computers resident at NAVOCEANO, Stennis Space Center, MS. The archived model output includes hourly three-dimensional fields of salinity, temperature and currents and water level across the model domain. Quality control is performed before the results go to a post-processing phase. A post-processing routine, which runs autonomously, generates surface current, temperature and salinity distributions after the completion of each cycle of forecast. The model results are available on the NGLI website (www.navo.navy.mil/NGLI) for public use.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115092550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Real-time high data rate acoustic link based on spatio-temporal blind equalization: the TRIDENT acoustic system 基于时空盲均衡的实时高数据速率声学链路:TRIDENT声学系统

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1192009

J. Trubuil, G. Lapierre, T. Le Gall, J. Labat

引用次数: 14

Towards better sonar performance predictions 更好的声纳性能预测

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1193297

H. T. Vosbein

引用次数: 2

An examination of coherence of directional wave time series from bottom-mounted pressure and current sensors 从底部安装的压力和电流传感器的定向波时间序列的相干性检查

OCEANS '02 MTS/IEEE Pub Date : 2002-10-29 DOI: 10.1109/OCEANS.2002.1191899

J. P. McKinney, G. Howell

{"title":"An examination of coherence of directional wave time series from bottom-mounted pressure and current sensors","authors":"J. P. McKinney, G. Howell","doi":"10.1109/OCEANS.2002.1191899","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1191899","url":null,"abstract":"This paper examines the coherence between kinematic variables from different types of bottom mounted instruments used for coastal directional wave measurements. Long term field data from PPP, PEMCM and PADV for several locations and wave conditions are analyzed for wave direction and coherence. Directional wave measurements analyzed from arrays of sensors assume that the time series of wave kinematics are statistically homogenous. Sensor time series should differ only in amplitude and phase. For real-world field measurements sensor data contains noise components and systematic errors and biases. Coherence between sensor pairs is a common method of quantifying the noise and error. Our results show very high coherence between individual pressure time series in short base-line pressure arrays. Slope components computed from the pressure array are used for directional analysis. We find slope coherence less than the scalar pressures but generally high. Coherence between U and V components of horizontal velocity measured by current meters should be very high because they are Cartesian components of the current vector. Our data show this is generally true for common E-M current meters. For acoustic Doppler (PADV) velocity meters the coherence was significantly lower. Coherence is potentially useful as a metric for comparing different sensor systems accuracy for directional estimates. It also is frequently used as a quality control test for automated data analysis. Non-acoustic systems generally exhibit high coherence when operating correctly. For acoustic systems, the question arises as how good must coherence be for acceptable data. We present exploratory analyses that examine then relationship between coherence and the quality of directional estimates.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116273262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0