2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)最新文献

{"title":"Wave mapping with HF radar","authors":"L. Wyatt","doi":"10.1109/CWTM.2011.5759519","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759519","url":null,"abstract":"This paper briefly reviews the theory behind wave measurement with HF radar. Data from a number of different deployments with different radars, at different frequencies, in different oceanographic conditions are used to demonstrate the wave mapping capability and to illustrate some of the problems that have arisen and solutions that have been identified. The examples show the spatial variability in coastal wave fields and hence demonstrate the value of HF radar measurements for wave-sensitive coastal engineering applications and for wave model validation and development.","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125432273","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":"Extended-range RiverSonde operation on the Hudson River","authors":"C. Teague, D. Barrick, P. Lilleboe, H. Roarty, D. Holden, Dakota Goldinger","doi":"10.1109/CWTM.2011.5759529","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759529","url":null,"abstract":"A RiverSonde was operated during June–August 2010 along the Hudson River in New Jersey at a location about 140 m from the water's edge with the antenna about 40 m above the water level. With this configuration, usable signals were obtained all the way across the river, out to a range of 1400 m from the radar. This was considerably greater than the 300 m which had been observed in previous experiments. Initial data processing shows that the along-channel velocity had the expected tidal signature with a maximum value of approximately 1 m/s and was nearly in phase with the stage measured about 5 km downstream at a NOAA gaging station.","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"475 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132588341","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":"Current and wave measurements in support of the Chesapeake Bay Interpretive Buoy System","authors":"W. D. Wilson, E. Siegel","doi":"10.1109/CWTM.2011.5759533","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759533","url":null,"abstract":"The Chesapeake Bay Interpretive Buoys System (CBIBS, www.buoybay.org) is - at present - a 9-buoy system of observational buoy platforms located around the Chesapeake Bay, operated bythe NOAA Chesapeake Bay Office. The buoys themselves are AXYS Watchkeeper buoys based on the Tideland Signal SB 138 P hull, moored with all chain rode with a 2.5∶1 scope. All of the buoys have downward looking NORTEK AquaDopp 1 mHz profilers mounted in the hulls; six of the buoys are equipped with AXYS TriAXYS OEM wave measurement modules. To evaluate the performance of these buoy mounted sensors, concurrent wave and current profile data were collected at one site (34 days of data at the SN ‘Six Foot Knoll’ buoy, 21 foot depth) using an adjacent bottom-mounted 1 mHz NORTEK Acoustic Wave and Current (AWAC) instrument. Using one Hz overlapping single ping current profile data, the following conclusions were reached: • Ten minute averages calculated and transmitted by the AXYS Watchman controller accurately represent internally recorded current profiler data (however the comparison revealed a correctable Watchman firmware error); • Over four 1-meter bins, absolute differences in magnitude among 10 minute means of AquaDopp and AWAC currents are less than 0.005 meters/second, with standard deviations of 0.02 – 0.03 meters/second; • Absolute differences in direction over the same bins were 7–10 degrees. By only including velocities in excess of 0.1 meters/second, direction errors were reduced by nearly one half; • AWAC and buoy currents were subjected to harmonic tidal analysis at each level. Differences in the orientation of the major axis of the tidal ellipses were 0.3 to 1.6 degrees; • Current measurement accuracy was not affected by sea state / buoy motion, at least up to the 1.5 meter waves heights experienced during this comparison; • An analysis of the ‘errors’ (assuming AWAC data as the standard) shows that accuracy does not improve after 120 pings (2 minutes) of averaging. In a power-limited environment such as a buoy, this is a significant result. Typical Chesapeake Bay wind waves - one to three feet height, two to three second period - are difficult to measure with a 1300-pound 1.75 meter diameter buoy. But accurately distinguishing between 1 and 2 foot waves is important to many of the small craft boaters using the CBIBS system. In comparing the TriAXYS (20 minute sample) and AWAC (2 Hz, 2048 samples) wave measurements, we found that for simple wave parameters of interest to us - maximum wave height and mean direction - the instruments were in good agreement. A linear fit to maximum wave heights had a slope / intercept of 1.05 / .02 (meters) . Similarly, comparison of mean wave direction from both instruments agreed well, with slope/intercept of 1.01 / –5.1 (degrees).","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"296 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133016570","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 currents in demanding environments with a Seaguard® RCM","authors":"I. Victoria","doi":"10.1109/CWTM.2011.5759558","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759558","url":null,"abstract":"As a result of joint efforts spearheaded by leading oceanographic institutions, several Seaguard® current meters have participated in a number of inter comparison studies in different parts of the world, covering areas from coastal shallow waters to deep ocean basins. From all these deployments, datasets of high quality have been obtained, despite the environmental conditions being sometimes far from ideal. The ability of the SEAGUARD® current meters (Aanderaa Data Instruments) using ZPulse™ technology to collect high quality data under difficult dynamic conditions (high tilts and mooring line vibration/rotations) as well as different backscatter levels will be discussed and illustrated with data from these deployments.","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123986256","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":"Using micro-bubbles as acoustic targets for large scale fluid flow experiments","authors":"L. Zedel, Spence Butt","doi":"10.1109/CWTM.2011.5759556","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759556","url":null,"abstract":"There are many times when it is useful to operate or test acoustic profiling and velocity sensors in laboratory facilities. Unfortunately, the often clean, clear water in such facilities provides little or no backscatter for these instruments to operate. Additional scatterers may be introduced in some cases but this can be unpractical in large facilities or may introduce volumes of particulate matter that are unacceptable. In this note, we describe the use of the Dissolved Air Floatation (DAF) method for creating large quantities of microscopic bubbles to serve as acoustic targets. The advantage of the approach is that it is comparatively inexpensive and does not contaminate the water in any way. A limitation of the approach is that bubbles rise through the water and therefore must be continuously produced. The method is demonstrated in the Institute of Ocean Technology — Ice Tank facility which is 12 m wide, 3 m deep, and 90 m long. In this tank, a large plume of bubbles could be injected at mid-depth and would collectively rise to the surface at a speed of 5 to 10 cm s−1. The rise speed for individual 100 µm bubbles expected from a DAF system is about 1 cm s−1 so it is likely that bubble residence time could be increased by dispersing the bubbles through the water column.","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128010373","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 wave breaking and surf zone width from a real-time cross-shore array of wave and current sensors at Duck, NC","authors":"R. Mulligan, J. Hanson, K. Hathaway","doi":"10.1109/CWTM.2011.5759540","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759540","url":null,"abstract":"Data from a cross-shore array of acoustic sensors at the US Army Corps of Engineers Field Research Facility is examined for evidence of wave transformation and longshore currents across the surf zone by comparing several events in 2009–10 with different wave statistics. Hurricane Bill (Hs = 3+ m, Tp = 18 s) was a long-period wave event with strong evidence of non-linear wave transformations, and a track that was offshore such that the coast received very little wind. A strong depth-uniform longshore current was observed at the 5 and 6 m sites (up to 1.8 m/s) that was in-phase with the wave energy. Weak currents were measured at the 8 and 11 m depth sites, indicating that the limit of the surf zone extended to between 6 and 8 m depth. Hurricane/Nor'easter Ida (Hs = 5+ m, Tp = 12 s) was a typical large wave event in the fall, with strong winds (wind-sea a major wave component) and rotating wind direction. Hurricane Earl (Hs = 4+ m, Tp = 15 s) was the first major wave event with all sensors in place, since the sensors at the 2 and 3 m depths were added in August 2010. For the selected events we present the observations of wave evolution across the surf zone. The offshore extent of wave breaking was determined from Argus Station imagery by analyzing pixel intensity for time exposure images along cross-shore transect. Surf zone widths are compared to the estimated extent of breaking by comparing wave energy across the array and the magnitude of the longshore current. The alongshore momentum balance was estimated to determine the contribution of radiation stress gradients to observed longshore current. The results provide a comparison of the seaward limit of the surf zone and width of the wave-driven current for different wave forcing conditions.","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115416882","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":"Studies of spatial and temporal surface current turbulence outside Golden Gate","authors":"D. Barrick, W. Rector","doi":"10.1109/CWTM.2011.5759542","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759542","url":null,"abstract":"This contribution examines the zero-mean random variability of surface currents seen by drifters and HF radar outside of Golden Gate in the Pacific. Seeding multiple drifters within cells of radar spatial and temporal scale sizes allows an understanding of this natural variability. Using the drifter velocity standard deviations to establish these turbulent motions is important in assessing radar errors, as it allows apportioning the differences between natural surface motions (that may not be of interest in studying mean flows) and radar noise. Numbers obtained in this study are about 4.1 cm/s for spatial and 1.2 cm/s for temporal drifter standard deviations, respectively. Similar numbers for radar standard deviations are 8.2 and 3.2 cm/s. RMS differences between radar and drifter radial velocities here are typically 8–9 cm/s.","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125322632","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":"Analysis and utilization of long-term data from a nearshore ADCP","authors":"W. Dally","doi":"10.1109/CWTM.2011.5759530","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759530","url":null,"abstract":"More than nine years of ADCP data have been collected in the nearshore at a field station at Spessard Holland North Beach Park, located in Melbourne Beach on the central Atlantic coast of Florida1. The nearly continuous record includes high-resolution directional wave spectra, current profiles, and tide elevations, and the data are being used to 1) study the characteristics of Florida's nearshore waves, particularly their directional distribution, 2) test the assumptions and methods commonly used by coastal practitioners, 3) test the ability of hindcast-driven transformation models to replicate nearshore waves, and 4) test the ability of storm surge models to replicate surge measured during hurricanes and other storms.","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121678105","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 waves and currents on a tidal flat in the Western Scheldt estuary","authors":"M. Schroevers, B. Huisman, M. Van der Wal, J. Terwindt","doi":"10.1109/CWTM.2011.5759539","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759539","url":null,"abstract":"In the Western Scheldt estuary a 45-day campaign took place to measure ship induced waves and currents on a tidal flat. It was established that the hydraulic loads due to the passing ships were large enough to play a major part in the erosion process of the tidal flat.","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126498440","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":"Historical developments of current, wave, and turbulence measurements including those by MAVS","authors":"A. Williams","doi":"10.1109/CWTM.2011.5759515","DOIUrl":"https://doi.org/10.1109/CWTM.2011.5759515","url":null,"abstract":"Personal knowledge of the author stretches from the Geodyne 850 current meter, predecessor of the VACM in 1969 to his own development of MAVS and its recent innovations. Housings, recording media, velocity sensors, and compasses have changed most noticeably. Applications of current measurements are next most striking about the developments in our field over the last 40 years. Where and how current meters are deployed have migrated from ship lowered or fixed moorings to bottom tripods, profilers on a mooring, and even to shore-based HF Radar antennas. Present developments address power to operate autonomous instrumentation, data communication in real time, and novel adaptations of current measurement techniques to non-traditional current measurement problems like horizontal profiles, turbulent mixing, and wave monitoring. New applications will be presented at this workshop, with perhaps greater emphasis than new developments in sensing.","PeriodicalId":345178,"journal":{"name":"2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM)","volume":"1036 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134458937","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}