Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1192109
S. Harrison, M.F. van Norden
The Naval Oceanographic Office (NAVOCEANO) has traditionally produced Special Tactical Oceanographic Information Charts (STOICs) that provide the warfighter with information superiority by describing the hydrographic/oceanographic nature of the battlespace in a paper chart or raster chart format. It is a compilation of information from all available sources, including imagery, foreign sources, historical data from databases, oceanographic models, and on-scene data collection. The centerpiece of a STOIC is the hydrographic chart, typically an 8/spl times/8 nautical mile area along a coast at 1:25,000 scale. This chart is surrounded by essential elements information, in text and graphic form, which succinctly describe environmental parameters that specifically affect mine warfare, special operations, and amphibious warfare. The present STOIC product cannot be simultaneously viewed with other geospatial data, such as route plans, order of battle, or terrain information, as required for achieving intelligence dominance of battlespace. In addition, the Navy is now transitioning to electronic navigation using Digital Nautical Charts (DNCs) and plans to be fully operational with Electronic Chart Display and Information Systems-Navy (ECDIS-N) on all ships by fiscal year 2004. To support these new geospatial capabilities, future NAVOCEANO tactical products will be based on standards-based geospatial information that allows for feature attribution and compliance with both NATO Digital Geographic Information Exchange Standard and the International Hydrographic Organization S-57 transfer standard. The new product line will be tactical layers that can be overlain on the DNC or Electronic Navigation Chart data and will exhibit the full functionality of ECDIS-N, the NATO Warship ECDIS, and other tactical decision aids. Battlespace visualization is changing, and NAVOCEANO intends to change as well to meet the needs of the 21st century warfighter. This paper outlines how NAVOCEANO will meet the challenge to modernize its tactical support by updating its production line.
{"title":"Electronic chart display overlay development at the Naval Oceanographic Office for use in tactical applications","authors":"S. Harrison, M.F. van Norden","doi":"10.1109/OCEANS.2002.1192109","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192109","url":null,"abstract":"The Naval Oceanographic Office (NAVOCEANO) has traditionally produced Special Tactical Oceanographic Information Charts (STOICs) that provide the warfighter with information superiority by describing the hydrographic/oceanographic nature of the battlespace in a paper chart or raster chart format. It is a compilation of information from all available sources, including imagery, foreign sources, historical data from databases, oceanographic models, and on-scene data collection. The centerpiece of a STOIC is the hydrographic chart, typically an 8/spl times/8 nautical mile area along a coast at 1:25,000 scale. This chart is surrounded by essential elements information, in text and graphic form, which succinctly describe environmental parameters that specifically affect mine warfare, special operations, and amphibious warfare. The present STOIC product cannot be simultaneously viewed with other geospatial data, such as route plans, order of battle, or terrain information, as required for achieving intelligence dominance of battlespace. In addition, the Navy is now transitioning to electronic navigation using Digital Nautical Charts (DNCs) and plans to be fully operational with Electronic Chart Display and Information Systems-Navy (ECDIS-N) on all ships by fiscal year 2004. To support these new geospatial capabilities, future NAVOCEANO tactical products will be based on standards-based geospatial information that allows for feature attribution and compliance with both NATO Digital Geographic Information Exchange Standard and the International Hydrographic Organization S-57 transfer standard. The new product line will be tactical layers that can be overlain on the DNC or Electronic Navigation Chart data and will exhibit the full functionality of ECDIS-N, the NATO Warship ECDIS, and other tactical decision aids. Battlespace visualization is changing, and NAVOCEANO intends to change as well to meet the needs of the 21st century warfighter. This paper outlines how NAVOCEANO will meet the challenge to modernize its tactical support by updating its production line.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"50 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":"121058881","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}
Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1191935
I. Adams, W. Jones, Jun-Dong Park, T. Kasparis, S. Chen, J. Tenerelli
Satellite microwave scatterometer wind retrievals, given in the standard product (e.g., QuikSCAT L2B), badly underestimate the peak wind speed in tropical cyclones. One important reason is that the effects of precipitation on the normalized radar cross section sigma-0 are neglected in the processing algorithms. This paper presents results of a first attempt to provide sigma-0 corrections, which account for the atmospheric attenuation of the rain. Atmospheric transmissivity is derived from the QuikSCAT Radiometer (QRAD) excess brightness temperatures taken simultaneously with sigma-0 measurements. When applied, retrieved wind speeds show improved agreement with numerical hurricane models (PSU/NCAR MM5) where there is moderate to high rainfall.
{"title":"Improved hurricane wind speed algorithm for the seawinds satellite scatterometer","authors":"I. Adams, W. Jones, Jun-Dong Park, T. Kasparis, S. Chen, J. Tenerelli","doi":"10.1109/OCEANS.2002.1191935","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1191935","url":null,"abstract":"Satellite microwave scatterometer wind retrievals, given in the standard product (e.g., QuikSCAT L2B), badly underestimate the peak wind speed in tropical cyclones. One important reason is that the effects of precipitation on the normalized radar cross section sigma-0 are neglected in the processing algorithms. This paper presents results of a first attempt to provide sigma-0 corrections, which account for the atmospheric attenuation of the rain. Atmospheric transmissivity is derived from the QuikSCAT Radiometer (QRAD) excess brightness temperatures taken simultaneously with sigma-0 measurements. When applied, retrieved wind speeds show improved agreement with numerical hurricane models (PSU/NCAR MM5) where there is moderate to high rainfall.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"89 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":"114705370","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}
Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1193265
T. Hyakudome, T. Aoki, T. Murashima, S. Tsukioka, H. Yoshida, H. Nakajoh, T. Ida, S. Ishibashi, R. Sasamoto
A deep and long cruising range AUV (autonomous underwater vehicle) named "URASHIMA" (AUV-EXI; development code name), has been developed by JANISTEC since 1998. URASHIMA can cruise long distance in the sea and collect sea data and water samples automatically for offshore exploration. The dimensions and weight of URASHIMA are 10m (L), 1.3m (W), 1.5m (H), and about 7.5 tons in the air. There are two very important key technologies for a long cruising range autonomous underwater vehicle. One technology is the power source. URASHIMA has two types of power sources. One is a high capacity lithium-ion rechargeable battery. The other one is solid polymer electrolyte fuel cell. With these power sources the vehicle capable of performing long ranges missions. The estimated cruising ranges are about 100 km by using battery and about 300 km by using fuel cell each other at three knots. The other technology is the navigation system. The AUV cruises independently without any communications between the mother ship and vehicle. It is very important to know its present position and forward environment. URASHIMA has highly accurate navigation sensors, such that the inertial navigation system (INS) consists of three sets of ring laser gyro and accelerometers, obstacle avoidance sonar (OAS), Doppler velocity log (DVL) and acoustic homing sonar. The AUV enables long distance cruising independently with these navigation sensors. The sea-going tests started in June 2000. The equipment, hardware, software, and autonomous functions, will be improved gradually. In these sea trials, URASHIMA achieved a dive to3518 m and cruised 132.5 km in autonomous navigation mode.
{"title":"Key technologies for AUV \"URASHIMA\"","authors":"T. Hyakudome, T. Aoki, T. Murashima, S. Tsukioka, H. Yoshida, H. Nakajoh, T. Ida, S. Ishibashi, R. Sasamoto","doi":"10.1109/OCEANS.2002.1193265","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1193265","url":null,"abstract":"A deep and long cruising range AUV (autonomous underwater vehicle) named \"URASHIMA\" (AUV-EXI; development code name), has been developed by JANISTEC since 1998. URASHIMA can cruise long distance in the sea and collect sea data and water samples automatically for offshore exploration. The dimensions and weight of URASHIMA are 10m (L), 1.3m (W), 1.5m (H), and about 7.5 tons in the air. There are two very important key technologies for a long cruising range autonomous underwater vehicle. One technology is the power source. URASHIMA has two types of power sources. One is a high capacity lithium-ion rechargeable battery. The other one is solid polymer electrolyte fuel cell. With these power sources the vehicle capable of performing long ranges missions. The estimated cruising ranges are about 100 km by using battery and about 300 km by using fuel cell each other at three knots. The other technology is the navigation system. The AUV cruises independently without any communications between the mother ship and vehicle. It is very important to know its present position and forward environment. URASHIMA has highly accurate navigation sensors, such that the inertial navigation system (INS) consists of three sets of ring laser gyro and accelerometers, obstacle avoidance sonar (OAS), Doppler velocity log (DVL) and acoustic homing sonar. The AUV enables long distance cruising independently with these navigation sensors. The sea-going tests started in June 2000. The equipment, hardware, software, and autonomous functions, will be improved gradually. In these sea trials, URASHIMA achieved a dive to3518 m and cruised 132.5 km in autonomous navigation mode.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"78 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":"114847109","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}
Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1191833
J. Zande, D. Sullivan, S. Butcher, T. Murphree
The Marine Advanced Technology Education (MATE) Center has developed a model for gathering information on the marine work force and providing educators and students with that information, along with educational experiences that help prepare students for ocean-related careers. One example of this model in action focuses on remotely operated vehicles (ROVs). With the help of professionals working in the field, the MATE Center has developed Knowledge and Skill Guidelines (KSGs) for ROV technicians. The Center has used its KSGs, and skill competencies identified from them, to guide the development of its subsea technology curricula, which includes the texts and accompanying instructor's handbook, "Introduction to Underwater Technology & Vehicle Design." The Mate Center has disseminated this curriculum to educators through faculty development institutes. These educators have incorporated their newly gained knowledge and experience into their classrooms, working with their students to design and build ROVs that many have entered into MATE-supported ROV competitions. These competitions are designed to provide students with real-world experience, highlight their learning, and connect them with employers and industry mentors. In this way, MATE's model is helping the Center to achieve its ultimate goal: to provide students with the skills and experiences to meet work force needs.
{"title":"The MATE model: a focused effort to improve marine technical education & meet work force needs","authors":"J. Zande, D. Sullivan, S. Butcher, T. Murphree","doi":"10.1109/OCEANS.2002.1191833","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1191833","url":null,"abstract":"The Marine Advanced Technology Education (MATE) Center has developed a model for gathering information on the marine work force and providing educators and students with that information, along with educational experiences that help prepare students for ocean-related careers. One example of this model in action focuses on remotely operated vehicles (ROVs). With the help of professionals working in the field, the MATE Center has developed Knowledge and Skill Guidelines (KSGs) for ROV technicians. The Center has used its KSGs, and skill competencies identified from them, to guide the development of its subsea technology curricula, which includes the texts and accompanying instructor's handbook, \"Introduction to Underwater Technology & Vehicle Design.\" The Mate Center has disseminated this curriculum to educators through faculty development institutes. These educators have incorporated their newly gained knowledge and experience into their classrooms, working with their students to design and build ROVs that many have entered into MATE-supported ROV competitions. These competitions are designed to provide students with real-world experience, highlight their learning, and connect them with employers and industry mentors. In this way, MATE's model is helping the Center to achieve its ultimate goal: to provide students with the skills and experiences to meet work force needs.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"39 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":"115038532","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}
Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1192118
V. Korochentsev, G.P. Turmov, V. Korochentsev, S. Shevkun
The synthesis and analysis of arrays in marine bays and closed basins were shown to be different from analogous questions in the deep sea. To form the beam pattern of an antenna working in continuous mode (impulses of long duration) one needs to take into consideration all factors, such as array shape, amplitude-phase distribution of particle velocity onto the array, bay geometry, acoustic features of water and sea bottom. We offer mathematical models of synthesis and analysis of the array placed in a marine bay. These models take into account factors of frontiers and bay bottom. The mathematical models are based on a strict solution of the Helmholtz equation by applying Green's function. The question of analysis and synthesis of the array is formulated as the exact task of mathematical physics. Results of digital exploration are reported.
{"title":"Synthesis of antennas located in a sea bay","authors":"V. Korochentsev, G.P. Turmov, V. Korochentsev, S. Shevkun","doi":"10.1109/OCEANS.2002.1192118","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192118","url":null,"abstract":"The synthesis and analysis of arrays in marine bays and closed basins were shown to be different from analogous questions in the deep sea. To form the beam pattern of an antenna working in continuous mode (impulses of long duration) one needs to take into consideration all factors, such as array shape, amplitude-phase distribution of particle velocity onto the array, bay geometry, acoustic features of water and sea bottom. We offer mathematical models of synthesis and analysis of the array placed in a marine bay. These models take into account factors of frontiers and bay bottom. The mathematical models are based on a strict solution of the Helmholtz equation by applying Green's function. The question of analysis and synthesis of the array is formulated as the exact task of mathematical physics. Results of digital exploration are reported.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"61 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":"114632266","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}
Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1192146
R. Ladner, F. Petry
Data mining or knowledge discovery refers to a variety of techniques having the intent of uncovering useful patterns and association from large databases. We have been working with data mining techniques for a variety of oceanographic data and have encountered a number of troublesome issues relative to available data. We describe the steps preparatory to data mining and three data mining techniques that we have applied to spatio-temporal data. We include a detailed review of various sources of geospatial, oceanographic and meteorological data and associated issues inherent in their use in knowledge discovery. We also provide issues relevant to the difficulties in providing an overall integration of this heterogeneous data for knowledge discovery.
{"title":"Knowledge discovery in oceanographic databases: issues of complications in data sources","authors":"R. Ladner, F. Petry","doi":"10.1109/OCEANS.2002.1192146","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192146","url":null,"abstract":"Data mining or knowledge discovery refers to a variety of techniques having the intent of uncovering useful patterns and association from large databases. We have been working with data mining techniques for a variety of oceanographic data and have encountered a number of troublesome issues relative to available data. We describe the steps preparatory to data mining and three data mining techniques that we have applied to spatio-temporal data. We include a detailed review of various sources of geospatial, oceanographic and meteorological data and associated issues inherent in their use in knowledge discovery. We also provide issues relevant to the difficulties in providing an overall integration of this heterogeneous data for knowledge discovery.","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":"121912115","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}
Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1192128
M. A. Rennick, J. Joseph, M.J. Schorp
The Fleet Numerical Meteorology and Oceanography Center provides meteorological and oceanographic support to civilian and military decision makers throughout the agencies planning and executing response to the terrorist attacks on the World Trade Center and the Pentagon. This support is in the form of observations, numerical forecast model output, and various products and services based on them. While these functions are not new to Fleet Numerical, the pace of operations and the breadth of the customer base have required a number of innovations in product generation, distribution, and display capabilities.
{"title":"Fleet numerical support for homeland security in the wake of 9/11","authors":"M. A. Rennick, J. Joseph, M.J. Schorp","doi":"10.1109/OCEANS.2002.1192128","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192128","url":null,"abstract":"The Fleet Numerical Meteorology and Oceanography Center provides meteorological and oceanographic support to civilian and military decision makers throughout the agencies planning and executing response to the terrorist attacks on the World Trade Center and the Pentagon. This support is in the form of observations, numerical forecast model output, and various products and services based on them. While these functions are not new to Fleet Numerical, the pace of operations and the breadth of the customer base have required a number of innovations in product generation, distribution, and display capabilities.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"52 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":"122101693","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}
Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1193287
M. Rendas, S. Rolfes
This paper presents results on the navigation of mobile underwater robots using maps of contours of distinct habitats of the sea-floor. The contour maps are acquired by autonomously tracking the boundaries of contrasting regions of the sea bed using a video camera mounted on the robot. Recognition of previously seen regions enable the robot to reset dead-reckoning errors, enabling consistent position estimates to be maintained.
{"title":"Underwater robot navigation using benthic contours","authors":"M. Rendas, S. Rolfes","doi":"10.1109/OCEANS.2002.1193287","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1193287","url":null,"abstract":"This paper presents results on the navigation of mobile underwater robots using maps of contours of distinct habitats of the sea-floor. The contour maps are acquired by autonomously tracking the boundaries of contrasting regions of the sea bed using a video camera mounted on the robot. Recognition of previously seen regions enable the robot to reset dead-reckoning errors, enabling consistent position estimates to be maintained.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"19 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":"123794832","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}
Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1192052
J. Kaihatu, K. Edwards, W. O'Reilly
Waves undergo significant transformation over complex bathymetry, and the resulting nearshore wave conditions can be sensitive to small changes in the offshore wave forcing. A potential consequence of this transformation sensitivity is large uncertainties in modeled nearshore waves owing to the amplification of the error in the deep water spectra used as initial conditions. In preparation for the upcoming Nearshore Canyon Wave Experiment in La Jolla, CA, a boundary condition sensitivity analysis was performed over the region's submarine canyon bathymetry using the SWAN wave model. The sensitivity analysis included varying the offshore spectrum discretization (frequency and directional bandwidths), the peak period and direction of the spectra, and the frequency and directional spreads. In each case, the magnitude of the spectral variations was governed by expected uncertainties when initializing a nearshore model with a) typical buoy data for the area, and b) global WAM model hindcasts or forecasts. In addition, data from the Torrey Pines Outer Buoy (located 12 km offshore) from the first week of November 2001 were used to initialize the model, and the maximum change seen in the domain over the course of the week were compared to those derived from the sensitivity analysis. The nearshore locations that showed the largest change in wave height over time were also the areas most sensitive to boundary condition errors, and correspond to areas of wave focusing. Errors in the estimation of the peak offshore wave direction were found to have the greatest impact on the accuracy of the nearshore wave predictions. The coarse directional resolution (15 degrees) of deep water spectra provided by the present generation of operational global models is shown to be a significant source of error when handcasting or forecasting nearshore waves over complex bathymetry.
{"title":"Model predictions of nearshore processes near complex bathymetry","authors":"J. Kaihatu, K. Edwards, W. O'Reilly","doi":"10.1109/OCEANS.2002.1192052","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192052","url":null,"abstract":"Waves undergo significant transformation over complex bathymetry, and the resulting nearshore wave conditions can be sensitive to small changes in the offshore wave forcing. A potential consequence of this transformation sensitivity is large uncertainties in modeled nearshore waves owing to the amplification of the error in the deep water spectra used as initial conditions. In preparation for the upcoming Nearshore Canyon Wave Experiment in La Jolla, CA, a boundary condition sensitivity analysis was performed over the region's submarine canyon bathymetry using the SWAN wave model. The sensitivity analysis included varying the offshore spectrum discretization (frequency and directional bandwidths), the peak period and direction of the spectra, and the frequency and directional spreads. In each case, the magnitude of the spectral variations was governed by expected uncertainties when initializing a nearshore model with a) typical buoy data for the area, and b) global WAM model hindcasts or forecasts. In addition, data from the Torrey Pines Outer Buoy (located 12 km offshore) from the first week of November 2001 were used to initialize the model, and the maximum change seen in the domain over the course of the week were compared to those derived from the sensitivity analysis. The nearshore locations that showed the largest change in wave height over time were also the areas most sensitive to boundary condition errors, and correspond to areas of wave focusing. Errors in the estimation of the peak offshore wave direction were found to have the greatest impact on the accuracy of the nearshore wave predictions. The coarse directional resolution (15 degrees) of deep water spectra provided by the present generation of operational global models is shown to be a significant source of error when handcasting or forecasting nearshore waves over complex bathymetry.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"9 6 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":"124127450","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}
Pub Date : 2002-10-29DOI: 10.1109/OCEANS.2002.1192006
D. Rouseff, J. Flynn, W. Fox, J. Ritcey
Passive Phase Conjugation is a method for coherent underwater acoustic communication that uses multiple receive-only hydrophones. The technique is essentially a space-time matched filter. Previous results from a field experiment demonstrating the method were reported by Rouseff et al. [IEEE J. Oceanic Eng. 26, pp. 821-831, 2001]. In this paper, performance results are presented for Decision-Directed Passive Phase Conjugation, an adaptive extension to the basic technique. Using decision directed estimates for the channel impulse response, the method requires training overhead of less than 2% for the 10000-symbol packets used in the experiment. Mean-Square-Error and Bit-Error-Rates are reported for various array configurations including a three-element horizontal array.
无源相位共轭是一种利用多个只接收水听器实现相干水声通信的方法。该技术本质上是一种时空匹配滤波器。roseff et al. [IEEE J. Oceanic engineering . 26, pp. 821-831, 2001]报道了先前的田间试验结果。本文给出了决策导向无源相位共轭的性能结果，这是对基本技术的自适应扩展。对信道脉冲响应使用决策导向估计，该方法对实验中使用的10000个符号包的训练开销要求小于2%。均方误差和误码率报告了各种阵列配置，包括三元素水平阵列。
{"title":"Decision-directed Passive Phase Conjugation for underwater acoustic communication: experimental results","authors":"D. Rouseff, J. Flynn, W. Fox, J. Ritcey","doi":"10.1109/OCEANS.2002.1192006","DOIUrl":"https://doi.org/10.1109/OCEANS.2002.1192006","url":null,"abstract":"Passive Phase Conjugation is a method for coherent underwater acoustic communication that uses multiple receive-only hydrophones. The technique is essentially a space-time matched filter. Previous results from a field experiment demonstrating the method were reported by Rouseff et al. [IEEE J. Oceanic Eng. 26, pp. 821-831, 2001]. In this paper, performance results are presented for Decision-Directed Passive Phase Conjugation, an adaptive extension to the basic technique. Using decision directed estimates for the channel impulse response, the method requires training overhead of less than 2% for the 10000-symbol packets used in the experiment. Mean-Square-Error and Bit-Error-Rates are reported for various array configurations including a three-element horizontal array.","PeriodicalId":431594,"journal":{"name":"OCEANS '02 MTS/IEEE","volume":"29 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":"125484947","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}
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