Pub Date : 2005-06-28DOI: 10.1109/CCM.2005.1506359
V. Grandi, A. Carta, L. Gualdesi, F. De Strobel, S. Fioravanti
An increased demand for shallow water current measurements, as a result of both military and environmental interest in littoral water activity, has recently accelerated the technological evolution of ADCPs. Long term (several months) deployments of ADCPs in heavily fished coastal waters are now relatively common. This paper describes the work conducted at NURC since the 90's in the field of trawl-safe ADCP platforms. This includes both the Barny Sentinel model and its more recent real-time evolution into the SEPTR that adds an automated water column profiler, additional sensors and two-way communication at regular intervals. It is intended for 3-6 month deployments in areas where water column instruments are at risk from fishing trawlers, but with real-time data return and control via two-way satellite communication. SEPTR includes a micro-controller based bottom platform which houses an ADCP, wave/tide gage, ambient noise sensor array, and a water column profiler buoy system. The profiler performs autonomous vertical profiling of CTD and Fluorometer-Scattering Meter within the water column at depths down to 100m. Two-way communication of data, position and control allows profile results to be returned in near-real time, and operational commands together with profile schedules to be sent to multiple profiler instruments.
{"title":"An overview of SEPTR: Shallow Water Environmental Profiler in a Trawl-Safe Real-Time configuration","authors":"V. Grandi, A. Carta, L. Gualdesi, F. De Strobel, S. Fioravanti","doi":"10.1109/CCM.2005.1506359","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506359","url":null,"abstract":"An increased demand for shallow water current measurements, as a result of both military and environmental interest in littoral water activity, has recently accelerated the technological evolution of ADCPs. Long term (several months) deployments of ADCPs in heavily fished coastal waters are now relatively common. This paper describes the work conducted at NURC since the 90's in the field of trawl-safe ADCP platforms. This includes both the Barny Sentinel model and its more recent real-time evolution into the SEPTR that adds an automated water column profiler, additional sensors and two-way communication at regular intervals. It is intended for 3-6 month deployments in areas where water column instruments are at risk from fishing trawlers, but with real-time data return and control via two-way satellite communication. SEPTR includes a micro-controller based bottom platform which houses an ADCP, wave/tide gage, ambient noise sensor array, and a water column profiler buoy system. The profiler performs autonomous vertical profiling of CTD and Fluorometer-Scattering Meter within the water column at depths down to 100m. Two-way communication of data, position and control allows profile results to be returned in near-real time, and operational commands together with profile schedules to be sent to multiple profiler instruments.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121478885","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506339
J.T. Wang, G.Y. Zhang, H. Hou
The nonlinear polarization-vector translation algorithm proposed by A.J. Poelman is expressed by ellipticity ratio and orientation angle on a right-handed circular/left-handed circular polarization vector basis. It is inconvenient in the processing of signals expressed by the polarization parameters of amplitude-ratio and relative phase on a horizontal/vertical polarization vector basis. A new expressed NPVT algorithm is given to solve this problem in this paper, and the relation between the two NPVT algorithms is described mathematically. A good performance is obtained by the application of the new algorithm in suppressing of sky-wave radio interference in an HF surface wave radar compared with some other polarization filters.
{"title":"New expressed nonlinear polarization vector translation and its application in HF Radar","authors":"J.T. Wang, G.Y. Zhang, H. Hou","doi":"10.1109/CCM.2005.1506339","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506339","url":null,"abstract":"The nonlinear polarization-vector translation algorithm proposed by A.J. Poelman is expressed by ellipticity ratio and orientation angle on a right-handed circular/left-handed circular polarization vector basis. It is inconvenient in the processing of signals expressed by the polarization parameters of amplitude-ratio and relative phase on a horizontal/vertical polarization vector basis. A new expressed NPVT algorithm is given to solve this problem in this paper, and the relation between the two NPVT algorithms is described mathematically. A good performance is obtained by the application of the new algorithm in suppressing of sky-wave radio interference in an HF surface wave radar compared with some other polarization filters.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121078705","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506355
K. Bosley, J. Dussault, C. McGrath, J. Stepnowski
The National Oceanic and Atmospheric Administration, National Ocean Service's Center for Operational Oceanographic Products and Services (CO-OPS) operates Physical Oceanographic Real Time Systems (PORTS/spl reg/) at many of our Nation's major sea ports to provide real-time information in support of safe and efficient maritime commerce. As part of on-going efforts to improve PORTS/spl reg/, COOPS has partnered with the U.S. Coast Guard (USCG) to install current measurement systems on existing navigation buoys. These systems consist of a "clamparatus" that secures a current profiler and electronics box to the buoy. The entire package weighs less than 200 pounds and is easily deployed using a small boat and a block and tackle. Data are sent to shore via spread-spectrum radios. Deployments up to seven months have been achieved because of the low power consumption of both the profiler and radios. The biggest challenge to date has been correcting the compass error induced by the steel buoy; initial compass calibrations have removed much of the magnetic deviation. The results of comparisons with current directions from bottom-mounted acoustic Doppler current profilers (ADCPs) are encouraging, showing agreement to within +/-13/spl deg/ when all data are included. The difference improves to 11/spl deg/ when speeds less than 12.9 cm/s (.25 knots) are omitted. Recent experiments include the collection of global positioning system (GPS) compass measurements during calibration.
{"title":"Real-time current measurements on U.S. Coast Guard navigation buoys","authors":"K. Bosley, J. Dussault, C. McGrath, J. Stepnowski","doi":"10.1109/CCM.2005.1506355","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506355","url":null,"abstract":"The National Oceanic and Atmospheric Administration, National Ocean Service's Center for Operational Oceanographic Products and Services (CO-OPS) operates Physical Oceanographic Real Time Systems (PORTS/spl reg/) at many of our Nation's major sea ports to provide real-time information in support of safe and efficient maritime commerce. As part of on-going efforts to improve PORTS/spl reg/, COOPS has partnered with the U.S. Coast Guard (USCG) to install current measurement systems on existing navigation buoys. These systems consist of a \"clamparatus\" that secures a current profiler and electronics box to the buoy. The entire package weighs less than 200 pounds and is easily deployed using a small boat and a block and tackle. Data are sent to shore via spread-spectrum radios. Deployments up to seven months have been achieved because of the low power consumption of both the profiler and radios. The biggest challenge to date has been correcting the compass error induced by the steel buoy; initial compass calibrations have removed much of the magnetic deviation. The results of comparisons with current directions from bottom-mounted acoustic Doppler current profilers (ADCPs) are encouraging, showing agreement to within +/-13/spl deg/ when all data are included. The difference improves to 11/spl deg/ when speeds less than 12.9 cm/s (.25 knots) are omitted. Recent experiments include the collection of global positioning system (GPS) compass measurements during calibration.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124631685","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506341
E. Terray, J. Ledwell, M. Sundermeyer, T. Donoghue, S. Bohra, A. Cunningham, P. Laroque, W. Lillycrop, C. Wiggins
We report preliminary results from a pilot experiment to image the dispersion of fluorescent dye in the ocean surface layer using an airborne LIDAR. In-situ observations of currents, stratification, and dye concentration were also made from a ship. We give an overview of the experiment, and propose an inversion method for estimating dye concentration from observations of fluorescence and backscatter.
{"title":"Airborne fluorescence imaging of the ocean mixed layer","authors":"E. Terray, J. Ledwell, M. Sundermeyer, T. Donoghue, S. Bohra, A. Cunningham, P. Laroque, W. Lillycrop, C. Wiggins","doi":"10.1109/CCM.2005.1506341","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506341","url":null,"abstract":"We report preliminary results from a pilot experiment to image the dispersion of fluorescent dye in the ocean surface layer using an airborne LIDAR. In-situ observations of currents, stratification, and dye concentration were also made from a ship. We give an overview of the experiment, and propose an inversion method for estimating dye concentration from observations of fluorescence and backscatter.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129635543","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506356
N. Pettigrew, J. Wallinga, F. Neville, K. Schlenker
The Gulf of Maine Ocean Observing System (GoMOOS) was established in the summer of 2001 as a real-time pilot integrated observing system that includes a comprehensive array of moored physical and optical sensors, shore based long-range HF radar systems, circulation and wave modeling, satellite observations, and Web delivery of data and data products. The system is automated and operational. The GoMOOS moored buoy array presently consists of 10 solar-powered, automated buoy systems that telemeter data hourly via cellular/iridium phone and GOES satellite transmitters. The operational protocol is that 20 buoys and instrument suites are rotated through the 10 locations on a six-month cycle. Current measurements are made at 2 m depth using Aanderaa RCM9 in situ Doppler current meters, and subsurface currents are made with downward-looking RIM Doppler profilers. In addition, near-surface currents in the Gulf of Maine are being measured using a 5-megahertz long-range HF radar system manufactured by CODAR Ocean Systems Inc. Comparisons of the three current measurement systems are presented, and the operational logistics of current monitoring using these technologies in the challenging Gulf of Maine environment is discussed.
{"title":"Gulf of Maine Ocean Observing System (GoMOOS): current measurement approaches in a prototype integrated ocean observing system","authors":"N. Pettigrew, J. Wallinga, F. Neville, K. Schlenker","doi":"10.1109/CCM.2005.1506356","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506356","url":null,"abstract":"The Gulf of Maine Ocean Observing System (GoMOOS) was established in the summer of 2001 as a real-time pilot integrated observing system that includes a comprehensive array of moored physical and optical sensors, shore based long-range HF radar systems, circulation and wave modeling, satellite observations, and Web delivery of data and data products. The system is automated and operational. The GoMOOS moored buoy array presently consists of 10 solar-powered, automated buoy systems that telemeter data hourly via cellular/iridium phone and GOES satellite transmitters. The operational protocol is that 20 buoys and instrument suites are rotated through the 10 locations on a six-month cycle. Current measurements are made at 2 m depth using Aanderaa RCM9 in situ Doppler current meters, and subsurface currents are made with downward-looking RIM Doppler profilers. In addition, near-surface currents in the Gulf of Maine are being measured using a 5-megahertz long-range HF radar system manufactured by CODAR Ocean Systems Inc. Comparisons of the three current measurement systems are presented, and the operational logistics of current monitoring using these technologies in the challenging Gulf of Maine environment is discussed.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126470558","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506331
N. Pettigrew, J. Wallinga, R. Fleming
Detailed field testing of a bottom-mounted Aanderaa RDCP600 Doppler profiler was conducted at a protected coastal embayment. The RDCP600 was compared for 30 days to a string of seven moored Aanderaa RCM9 MKII in situ Doppler current meters, and an RDI 600 kHz workhorse ADCP. The test buoy was equipped with outriggers to allow measurements very close to the surface and to examine the acoustic and wake effects of the buoy on the performance of the RCM9 standard. The two 600 kHz Doppler profilers were deployed on the same bottom frame in order to ensure the same tilt and distance (approximately 50 m) from the moored RCM9 current meters. The Doppler profilers were programmed to sample during alternating time windows within a 20-minute sampling interval in order to avoid acoustic cross talk and interference. A common time base was achieved via post-deployment linear interpolation. Results of vector correlations and difference statistics show excellent agreement between all of the current measurement devices. Mean differences were generally less than 0.005 m s' and the RMS differences were on the order of 0.02 m s/sup -1/.
对Aanderaa RDCP600型海底多普勒剖面仪进行了详细的现场测试。将RDCP600与7个系泊的Aanderaa RCM9 MKII原位多普勒电流计和RDI 600 kHz主力ADCP进行了30天的比较。测试浮标配备了外伸臂，可以非常接近水面进行测量，并检查浮标对RCM9标准性能的声学和尾流影响。两个600 kHz多普勒分析器部署在同一个底部框架上，以确保与系泊的RCM9电流计保持相同的倾斜度和距离(约50米)。为了避免声串扰和干扰，多普勒谱仪被编程为在20分钟采样间隔内的交替时间窗进行采样。通过部署后的线性插值实现了一个共同的时间基础。矢量相关和差异统计的结果表明，目前所有的测量设备之间的一致性很好。平均差值一般小于0.005 m s’，均方根差值约为0.02 m s/sup -1/。
{"title":"Field comparison tests of a bottom-mounted Aanderaa RDCP600 with an RDI Workhorse 600 ADCP, and a moored string of Aanderaa RCM9 MKII current meters","authors":"N. Pettigrew, J. Wallinga, R. Fleming","doi":"10.1109/CCM.2005.1506331","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506331","url":null,"abstract":"Detailed field testing of a bottom-mounted Aanderaa RDCP600 Doppler profiler was conducted at a protected coastal embayment. The RDCP600 was compared for 30 days to a string of seven moored Aanderaa RCM9 MKII in situ Doppler current meters, and an RDI 600 kHz workhorse ADCP. The test buoy was equipped with outriggers to allow measurements very close to the surface and to examine the acoustic and wake effects of the buoy on the performance of the RCM9 standard. The two 600 kHz Doppler profilers were deployed on the same bottom frame in order to ensure the same tilt and distance (approximately 50 m) from the moored RCM9 current meters. The Doppler profilers were programmed to sample during alternating time windows within a 20-minute sampling interval in order to avoid acoustic cross talk and interference. A common time base was achieved via post-deployment linear interpolation. Results of vector correlations and difference statistics show excellent agreement between all of the current measurement devices. Mean differences were generally less than 0.005 m s' and the RMS differences were on the order of 0.02 m s/sup -1/.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134289918","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506325
J. Candy, E. Sullivan
Ship noise is a major contributor to towed array measurement uncertainties that can lead to large estimation errors. Many approaches ignore this problem, since they rely on inherent narrowband processing to remove these effects. The overall signal-to-noise ratio (SNR) available is therefore decreased making the signal extraction problem more difficult. In this paper we discuss the development of an adaptive model-based processor (AMBP) for signal enhancement from a set of noisy hydrophone measurements contaminated with tow ship noise. These results provide a solution to the adaptive joint cancellation/signal enhancement problem. Here we concentrate on the underlying theoretical development demonstrating the relationship between the canceller and model-based signal enhancer.
{"title":"Cancelling tow ship noise using an adaptive model-based approach","authors":"J. Candy, E. Sullivan","doi":"10.1109/CCM.2005.1506325","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506325","url":null,"abstract":"Ship noise is a major contributor to towed array measurement uncertainties that can lead to large estimation errors. Many approaches ignore this problem, since they rely on inherent narrowband processing to remove these effects. The overall signal-to-noise ratio (SNR) available is therefore decreased making the signal extraction problem more difficult. In this paper we discuss the development of an adaptive model-based processor (AMBP) for signal enhancement from a set of noisy hydrophone measurements contaminated with tow ship noise. These results provide a solution to the adaptive joint cancellation/signal enhancement problem. Here we concentrate on the underlying theoretical development demonstrating the relationship between the canceller and model-based signal enhancer.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124974860","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506347
C. Huhta, Y. Choquette
The Argonaut-SW is an acoustic Doppler current meter designed for water level, velocity and flow monitoring in rivers and channels. When working in ice affected rivers, some means of determining if ice is present is required to provide accurate flow data. Using data collected with an Argonaut-SW in the Chateauguay River in Quebec, Canada in 2004, algorithms were developed that allow the Argonaut-SW to detect the presence or absence of ice on a river in real-time. These algorithms were developed using data collected during winter and ice break up in the spring of 2004. The new algorithms have been tested at a number of sites during the freeze up and winter of 2004-2005. The ice detection algorithms provide a reliable and highly efficient means of detecting ice formation on the river. The Argonaut-SW also provides reliable stage, velocity and flow data while operating under ice. Combined with the ice detection data, this allows for substantial improvement in flow monitoring on ice affected rivers. Data from a number of Argonaut-SW installations involving flow under ice conditions will be presented, both with respect to the ice detection algorithms and the overall flow monitoring capabilities.
{"title":"Ice detection and under-ice flow monitoring using a SonTek Argonaut-SW","authors":"C. Huhta, Y. Choquette","doi":"10.1109/CCM.2005.1506347","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506347","url":null,"abstract":"The Argonaut-SW is an acoustic Doppler current meter designed for water level, velocity and flow monitoring in rivers and channels. When working in ice affected rivers, some means of determining if ice is present is required to provide accurate flow data. Using data collected with an Argonaut-SW in the Chateauguay River in Quebec, Canada in 2004, algorithms were developed that allow the Argonaut-SW to detect the presence or absence of ice on a river in real-time. These algorithms were developed using data collected during winter and ice break up in the spring of 2004. The new algorithms have been tested at a number of sites during the freeze up and winter of 2004-2005. The ice detection algorithms provide a reliable and highly efficient means of detecting ice formation on the river. The Argonaut-SW also provides reliable stage, velocity and flow data while operating under ice. Combined with the ice detection data, this allows for substantial improvement in flow monitoring on ice affected rivers. Data from a number of Argonaut-SW installations involving flow under ice conditions will be presented, both with respect to the ice detection algorithms and the overall flow monitoring capabilities.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123223300","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 : 2005-06-28DOI: 10.1109/CCM.2005.1506340
J. Dugan, C. Piotrowski
Knowledge of the circulation in rivers and estuaries is important for a number of routine as well as emergency operations. However, spatial-temporal characteristics of currents are difficult to measure using presently available instrumentation, particularly in the case of tides in complex morphology. This paper provides initial results for a new technique using a small aircraft, thereby enabling potential for rapid, repeated, high-resolution maps of near-surface currents over a large area. A sequence of EO images is mapped to a common geodetic coordinate frame on the surface. A dense grid of 3D space-time data cubes is assembled, and the 3D frequency-wavenumber spectrum of emitted light is calculated in each. An apparent low-frequency 2D planar spectral surface is found in most of the spectral cubes. This appears to be caused by variations in emitted light scattered from the near-surface sediment load. This planar surface represents advection of this scalar variable by the local mean flow vector, as per G.I. Taylor's "frozen flow" law for turbulent eddies embedded in the flow. The orientation of this surface in the spectral cube provides an accurate measurement of the speed and direction of the mean flow in each data cube, and the "thickness" of this surface potentially is a measure of the turbulence level. Maps of current vector retrievals are realistic, and specific numerical values agree with sparsely available ADCP data, typically within 10% rms normalized speed.
{"title":"Estuarine flows measured from an aircraft","authors":"J. Dugan, C. Piotrowski","doi":"10.1109/CCM.2005.1506340","DOIUrl":"https://doi.org/10.1109/CCM.2005.1506340","url":null,"abstract":"Knowledge of the circulation in rivers and estuaries is important for a number of routine as well as emergency operations. However, spatial-temporal characteristics of currents are difficult to measure using presently available instrumentation, particularly in the case of tides in complex morphology. This paper provides initial results for a new technique using a small aircraft, thereby enabling potential for rapid, repeated, high-resolution maps of near-surface currents over a large area. A sequence of EO images is mapped to a common geodetic coordinate frame on the surface. A dense grid of 3D space-time data cubes is assembled, and the 3D frequency-wavenumber spectrum of emitted light is calculated in each. An apparent low-frequency 2D planar spectral surface is found in most of the spectral cubes. This appears to be caused by variations in emitted light scattered from the near-surface sediment load. This planar surface represents advection of this scalar variable by the local mean flow vector, as per G.I. Taylor's \"frozen flow\" law for turbulent eddies embedded in the flow. The orientation of this surface in the spectral cube provides an accurate measurement of the speed and direction of the mean flow in each data cube, and the \"thickness\" of this surface potentially is a measure of the turbulence level. Maps of current vector retrievals are realistic, and specific numerical values agree with sparsely available ADCP data, typically within 10% rms normalized speed.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2005-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129619939","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 : 1900-01-01DOI: 10.1109/ccm.2005.1506354
R. Cole, R. Weisberg, N. Trenaman, K. Amundsen
Scientists, engineers and graduate students at the University of South Florida's (USF) College of Marine Science (CMS), Ocean Circulation Group (OCG) maintain a real-time monitoring program in the eastern Gulf of Mexico called the Coastal Ocean Monitoring and Prediction System (COMPS), an array of surface and bottom mounted buoys and moorings offshore spanning the west Florida shelf (WFS) from the panhandle to the Dry Tortugas. Recognizing the need for adding wave measurements from the near-shore environment to this program, testing began acquiring data from field instrumentation with a focus on data transmission acoustically, in real-time. This paper evaluates the success in collecting wave measurements with a bottom mounted RD Instruments (RDI) acoustic Doppler current profiler (ADCP/spl trade/) with Waves Technology, and NEMO, RDI's new Real Time Waves Processing Module, designed specifically for RDI Waves users condensing currents and waves data at the ADCP for transmission to the surface, and then sending these data via acoustic modems (wireless, Benthos, Inc.) through the water column to the surface. Data are then linked through a multipoint radio transceiver system (RF, FreeWave Technologies) back to USF for Web page posting. The site, components, data collection, and comparison between recorded data vs. transmitted data will be discussed and summarized. We conclude that this is a viable yet not trivial means of data collection and telemetry for future products added to the COMPS program.
{"title":"Wireless waves","authors":"R. Cole, R. Weisberg, N. Trenaman, K. Amundsen","doi":"10.1109/ccm.2005.1506354","DOIUrl":"https://doi.org/10.1109/ccm.2005.1506354","url":null,"abstract":"Scientists, engineers and graduate students at the University of South Florida's (USF) College of Marine Science (CMS), Ocean Circulation Group (OCG) maintain a real-time monitoring program in the eastern Gulf of Mexico called the Coastal Ocean Monitoring and Prediction System (COMPS), an array of surface and bottom mounted buoys and moorings offshore spanning the west Florida shelf (WFS) from the panhandle to the Dry Tortugas. Recognizing the need for adding wave measurements from the near-shore environment to this program, testing began acquiring data from field instrumentation with a focus on data transmission acoustically, in real-time. This paper evaluates the success in collecting wave measurements with a bottom mounted RD Instruments (RDI) acoustic Doppler current profiler (ADCP/spl trade/) with Waves Technology, and NEMO, RDI's new Real Time Waves Processing Module, designed specifically for RDI Waves users condensing currents and waves data at the ADCP for transmission to the surface, and then sending these data via acoustic modems (wireless, Benthos, Inc.) through the water column to the surface. Data are then linked through a multipoint radio transceiver system (RF, FreeWave Technologies) back to USF for Web page posting. The site, components, data collection, and comparison between recorded data vs. transmitted data will be discussed and summarized. We conclude that this is a viable yet not trivial means of data collection and telemetry for future products added to the COMPS program.","PeriodicalId":264883,"journal":{"name":"Proceedings of the IEEE/OES Eighth Working Conference on Current Measurement Technology, 2005.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116532853","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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