2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)最新文献

{"title":"Current and turbulence measurement with collocated ADP and turbulence profiler data","authors":"Hanna Torrens-Spence, P. Schmitt, P. Mackinnon, B. Elsaesser","doi":"10.1109/CWTM.2015.7098131","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098131","url":null,"abstract":"This paper presents a current and turbulence measurement campaign conducted at a test site in an energetic tidal channel known as Strangford Narrows, Northern Ireland. The data was collected as part of the MaRINET project funded by the EU under their FP7 framework. It was a collaborative effort between Queen's University Belfast, SCHOTTEL and Fraunhofer IWES. The site is highly turbulent with a strong shear flow. Longer term measurements of the flow regime were made using a bottom mounted Acoustic Doppler Profiler (ADP). During a specific turbulence measurement campaign, two collocated instruments were used to measure incoming flow characteristics: an ADP (Aquadopp, Nortek) and a turbulence profiler (MicroRider, Rockland Scientific International). The instruments recorded the same incoming flow, so that direct comparisons between the data can be made. In this study the methodology adopted to deploy the instruments is presented. The resulting turbulence measurements using the different types of instrumentation are compared and the usefulness of each instrument for the relevant range of applications is discussed. The paper shows the ranges of the frequency spectra obtained using the different instruments, with the combined measurements providing insight into the structure of the turbulence across a wide range of scales.","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"23 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125786209","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}

{"title":"Evaluation of algorithms for wave height measurements with high frequency radar","authors":"H. Roarty, C. Evans, S. Glenn, Hao Zhou","doi":"10.1109/CWTM.2015.7098109","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098109","url":null,"abstract":"Ocean wave conditions impact navigation, offshore operations, recreation, fisheries, safety of life at sea and hence the economic stability of any country's maritime sector. Making accurate measurements of wave conditions will help validate wave models and will help with forecasts of the wave conditions over the next few days. The United States has put forth “A National Operational Wave Observation Plan” to meet this need. It has called for 133 wave measurements in the coastal zone. High Frequency radar systems that are already in place can be one type of sensor to fill this measurement gap. Seven 13 MHz HF radars collected wave data along the coast of New Jersey from February 1, 2012 to June 1, 2012. The measurements from the radars utilizing existing algorithms were compared with wave measurements from accelerometer measurements aboard National Buoy Data Center platforms. Since there were large distances between the comparison points we first determined what the correlation was amongst the various buoy platforms to gauge the variability within the region. This provided a baseline for the comparison between the HF radar measurements and the nearby buoy measurements. We then evaluated three new wave measurement algorithms at one of the radar stations to see if that improved the measurements. The correlation of the radar wave measurements with that of the buoy varied considerably. We then chose one radar station that had good correlation with the buoy measurement and tested new algorithms to extract the wave information from the radar spectra. In each case, the comparison between the in situ record with the new algorithm showed improvement. The measurement of wave information with the radar showed moderate correlation with the in situ measurements. The four algorithms each showed improvement over the existing one. HF radar could be a sensor to play a role in the US national waves plan.","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127532978","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}

{"title":"Validation of areal wave and current measurements based on X-band radar","authors":"K. Hessner, S. Wallbridge, T. Dolphin","doi":"10.1109/CWTM.2015.7098102","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098102","url":null,"abstract":"Coastal waters are characterised by complex wave fields that are influenced by inhomogeneous bathymetries, and changing tidal- and wind-induced currents. Understanding these interactions is important for coastal engineering and environmental management. Remote sensing techniques, such as radar for flow field data collection, increase the amount of available information. Unlike in-situ techniques (e.g. buoys, or moored current meters), remote sensing can provide continuous observation of several parameters (waves, currents and bathymetry) simultaneously across a wide area. The wave and current monitoring system, WaMoS II, is a remote sensing system using standard nautical X-Band radars generally used for navigation and ship traffic control. Nautical radars are designed to monitor the sea surface continuously over a relative large area (~ 10 km2) with high spatial (~7.5 m) and temporal resolution (~2 s). Under various conditions, signatures of the sea surface itself become visible in the near range (less than 3 nautical miles) of such radar images. These signatures include spatial and temporal information of the sea surface waves (wind/sea and swell), currents and in shallow water also about the local water depth. In recent years, development has focussed on retrieving current and wave data at that high resolution on an operational basis (Hessner et al., 2007 [1]; Hessner and Bell, 2009, Hessner et al. 2014). In this paper, a brief introduction will be given to the high resolution current and water depth measurement principles of WaMoS II. WaMoS II current and wave data will be shown from the Sizewell test site, where a system has been installed since September 2013. This site is located on the East coast of England, an area of coastline which has been intensively studied over many decades. The hydrodynamics of this area are characterised by strong prevailing tidal currents with current magnitudes between 1-1.5m/s and a strongly bi-directional wave climate. The WaMoS II system at this site, operates in connection with a Kelvin Hughes (Manta Digital) with a horizontally polarized 8 ft antenna and a radar repetition rate of 1.34s. The antenna is mounted 66m above sea level. The area of radar observation ranges from 150m to 4000m, off shore (0-180° relative to N). The system delivers standard sea state measurements with an update rate of 2 min and high resolution current and depth information in a range up to 4 km with an update rate of 20 minutes and a spatial resolution of about 180m. The observation area is characterised by a straight North-Southward aligned coastline and an offshore sandbank with varying water depth between 5-15m. The localised effect of the bank on the wave and flow fields is thought to have significant impact at the shoreline. The complex hydrodynamics and spatially varying currents would be impossible to monitor at the appropriate scale with point measurements only. Here typical tidal states and sea state conditions will be dis","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128317713","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}

{"title":"Surface current measurements using marine radars","authors":"J. Horstmann, R. Carrasco, J. Seemann, M. Cysewski","doi":"10.1109/CWTM.2015.7098139","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098139","url":null,"abstract":"Within this paper we investigate the possibilities of measuring surface currents utilizing incoherent and coherent microwave radar operating at X-band near grazing incidence. The measured radar backscatter enables to measure the surface waves in space and time and therefore the surface current via the dispersion relation of surface waves. The Doppler velocities measured by the radar are modulated by contributions from the wind, current as well as waves and therefore enable to obtain additional information on the surface currents and surface waves.","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129255751","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}

{"title":"Observations of near-seabed currents induced by very large internal solitary waves over a sand dune field in the South China sea","authors":"D. B. Reeder, Y. Yang","doi":"10.1109/CWTM.2015.7098125","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098125","url":null,"abstract":"Internal waves are known to generate currents sufficient to suspend seabed sediment. Presented here are firstever measurements of the near-seabed currents over a sand dune field in the South China Sea (SCS) during the passage of internal solitary waves (ISW) in June 2014 aboard the R/V Ocean Research V (OR5). Horizontal currents were observed to exceed 100 cm/s, reaching as high as 200 cm/s in one case, while vertical currents were observed to reach 30 cm/s. The Shields parameter for this environment exceeds 0.1, indicating that the ISWinduced currents are sufficient to suspend and transport the available sediment, supporting the hypothesis that the ISW's are the generation mechanism of the very large subaqueous sand dunes on the upper continental slope of the northwestern SCS.","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124060715","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}

{"title":"Measuring ship-induced currents in a canal","authors":"M. Schroevers, K. Berends, T. Vermaas, H. Verheij","doi":"10.1109/CWTM.2015.7098126","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098126","url":null,"abstract":"A full scale experiment using a deep loaded push-tow barge combination was carried out to determine the stability of a canal bed against future loads. The resulting currents and bed erosion were monitored and showed that the canal bed will not be stable at the expected future loads.","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131080793","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}

{"title":"Automating the quality screening of acoustic Doppler current profiler data","authors":"P. Wanis, D. Symonds, Matt Hull","doi":"10.1109/CWTM.2015.7098145","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098145","url":null,"abstract":"Acoustic Doppler Current Profiler (ADCP) measurements employ a large number of sensors and are deployed in a complex environment. Because of the complexity of the instrument and the environment it is sensing, its measurements are subject to a large number of factors that can potentially corrupt the resulting measurements synthesized from those sensor data. Therefore, the need to perform Quality Assurance (QA) and Quality Control (QC) processing of the data has long been recognized. Historically these techniques have been disparate and highly dependent on the instrument, deployment environment, and individuals processing the data. More recently there have been efforts to standardize the parameters and techniques used in the QA and QC screening of data. As these parameters for quality screening and assessment become more standardized, they become more and more amenable to automated processing. In this paper we provide an overview of the current standards and best practices for quality assurance of ADCP data, and generalize these standards and best practices into a high-level flow for processing data and assessing the quality of the resultant output data product. We provide an overview of a software package that automates the closely related problem of performing Quality Assurance on ADCP data collected for the purposes of measuring river discharge, and provide an overview of how this software solution could be adapted to satisfy the needs of the oceanographic community.","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122758413","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}

{"title":"Measuring the landward gulf stream front variability off Cape Hatteras with HF radar","authors":"M. Muglia, H. Seim, S. Haines","doi":"10.1109/CWTM.2015.7098152","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098152","url":null,"abstract":"A decade of coastal ocean radar surface current observations of the Gulf Stream off Cape Hatteras, NC have been collected that offer to provide key new insights into the temporal and spatial variability of the Gulf Stream in this region. The Gulf Stream is believed to have a profound influence on the complex current dynamics off of Cape Hatteras, NC that result from the convergence of many different water masses in the region. Although essential to understanding oceanography off the NC coast, and to linkages beyond the region, Gulf Stream variability in this area has been difficult to quantify because of the challenge involved in obtaining observations of consistent spatial and temporal resolution over long time periods. Analysis of Long Range Seasonde Coastal Ocean Radar (Codar) ocean surface current measurements from two sites in NC may provide estimates of the landward Gulf Stream edge over a nearly continuous ten-year period. Radar surface current measurements are made hourly, more frequently than satellite measurements, and provide more consistent coverage of the Gulf Stream than many historical measurement techniques. The 5MHz radars typically make surface current measurements across the entire cyclonic shear zone on the landward side of the Gulf Stream. These measurements may provide methods to define Gulf Stream location, width, transport and variability of these properties over time and alongshore, providing insights into the current dynamics off Cape Hatteras, NC. We here present a method to identify the landward Gulf Stream position and width of the cyclonic shear zone from radar surface currents. The method of front detection developed associates the landward Gulf Stream front with maxima in the radial current shears. Maxima are chosen within regions of consistent coverage over the time period sampled. The locations where the Gulf Stream first enters and exits the radar coverage area are apparent as large radial speeds measured by the radar, and one bearing is chosen from each region for analysis. However in a region between these two zones the Gulf Stream is perpendicular to the radials and the method can not be used. This method can be applied to each of three radars located in the vicinity of Cape Hatteras.","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125276355","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}

{"title":"Application of acoustic tomography in shallow waters","authors":"M. Razaz, L. Zedel, A. Hay, K. Kawanisi, Noriaki Goda","doi":"10.1109/CWTM.2015.7098141","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098141","url":null,"abstract":"This paper briefly introduces a state-of-the-art timeof- travel sensor that enables application of acoustic tomography for measuring range-averaged current velocity in extremely shallow waters. The system is called Fluvial Acoustic Tomography and has been developed in Hiroshima University. The paper presents two experiments, the first of which aims at evaluating FAT accuracy in measuring mean flow direction and velocity in an estuarine environment characterized by strong stratification. Second study investigates the applicability of FAT for long-term continuous monitoring of tidal currents in a narrow strait, where is a potential site for installation of a small tidal turbine. During each experiment a set of reference data was collected using a moving-boat ADCP. The results obtained in the first campaign indicate remarkable consistency between FAT and ADCP. It was found that the relative error in the mean flow directions reported by FAT and ADCP did not exceed 10%. The results obtained in the second experiment indicate the agreement between tomographically derived velocities with ADCP in coastal areas. The results also signify the importance of angularity error involved in recovering flow velocity when FAT with only one raypath is used.","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125092062","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}

{"title":"Hub-height time series measurements of velocity and dissipation of turbulence kinetic energy in a tidal channel","authors":"R. Lueck, F. Wolk, Jeremy Hancyck, K. Black","doi":"10.1109/CWTM.2015.7098143","DOIUrl":"https://doi.org/10.1109/CWTM.2015.7098143","url":null,"abstract":"The Nemo turbulence measurement system is an anchored, buoyant float designed to measure time-series of current velocity, velocity shear, and turbulent kinetic energy (TKE) dissipation rates in swift tidal channels. The system consists of a 4.5 m long streamlined float made from syntactic foam, with cutouts to house various instrument components: a 600 kHz downward-looking acoustic Doppler current profiler (ADCP); an acoustic Doppler velocimeter (ADV); and a turbulence module equipped with velocity shear probes and fast-response thermistors The system was successfully deployed over a two-week period in Islay Sound, a tidal channel between Islay and Jura Islands, Scotland, where flow speeds exceed 3 m/s. The depth of the channel was 53 m and the system was deployed such that it remained within the depth aperture of a proposed tidal energy extraction rotor. This environment represented significant challenges for the design of the mooring and the turbulence instrumentation. We describe the measurement system and its performance in terms of attitude and flight dynamics including a synopsis of time series of current velocities and shear probe turbulence data. Scientific interpretation will be presented in subsequent publications.","PeriodicalId":356185,"journal":{"name":"2015 IEEE/OES Eleveth Current, Waves and Turbulence Measurement (CWTM)","volume":"22 27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134177019","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}