The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The Tenth Working Conference on Current Measurement Technology (CMTC) is actually the first Current, Waves and Turbulence Measurement Workshop (CWTM). This conference is a direct descendent of the CMTC workshops of former years. The theme of this conference is “Advances in Lagrangian and Eulerian Measurement Techniques and Observations of Current, Waves and Turbulence.” Like the previous Conferences,...
A Special Session on Standards in Current, Waves, and Turbulence Measurements was held Tuesday March 22 from 1 PM to 3PM. This was an open discussion moderated by Sandy Williams who is Technological Committee Co-Chair with Steve Holt of the OES Standards Committee and Don Barrick who is President and CEO of CODAR SeaSonde. The agenda for our discussion included the following issues: Results of our...
The ability of coastal HF radars to map ocean surface currents was demonstrated in the early 70s at NOAA in the U.S. Since that time, there was a push to develop this technology into a useful, affordable tool that would fill a big gap: nothing else out there could map surface currents continuously over space and time, and the same holds true today. But who would use these data?
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...
Phased array surface current and wave radar systems use electronic beam steering technology to receive radio wave backscatter from the sea surface in narrow beams. This session will present objective information on phased array surface current and wave radar systems by vendors and users.
This paper introduces the over-the-horizon radar technique optimized for oceanographic applications. The relation between radar range and operating frequency will be explained as well as the radar resolution which depends on the radar bandwidth. The accuracy in azimuth strongly depends on the number of used receive antennae and samples demonstrate the high accuracy that can be achieved. The oceanographic...
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...
Since April 2006, long range (8.3MHz) WERA HF radars have been operated on the Southeastern United States coastline, as part of the U.S. Integrated Ocean Observing System (IOOS) and in particular the national HF Radar network. These radars measure currents operationally, and waves and winds experimentally across the wide continental shelf of Georgia (GA) and South Carolina (SC). Half-hourly data at...
Maritime domain awareness is important for coastal nations in terms of applications to coastal conservancy, security, fishery and stewardship of their exclusive economic zones (EEZs). Maritime situational awareness involves knowing the location, speed and bearing of ships and boats in the EEZ. HF radar is a useful tool in providing ship information in real time. It is especially effective when combined...
The selection of San Francisco Bay as the venue for the 2013 America's Cup competition provides the opportunity to highlight the technology available for measuring surface currents over the entire proposed racecourse and to deliver current estimates in near real-time. Using an array of CODAR Ocean Sensors SeaSonde 42 MHz systems, the currents in Central San Francisco Bay can be mapped in high spatial...
Several recent tests with HF radars, closely packed drifters, and closely spaced ADCPs, have revealed a sub grid-scale spatial variability near the surface that disappears with depth. This impacts interpretation and measurement of instrument accuracy. For example, RMS difference of velocity between two sensors is not simply a measure of instrument error. Can such measurements of spatial turbulence...
In the South-Eastern part of the North Sea, known as the German Bight, the Helmholz-Zentrum Gessthacht (HZG, former GKSS Research Center) is currently installing the experimental observation Network “Coastal Observing System for Northern and Arctic Seas” (COSYNA). The main components of COSYNA include in situ instruments, a network of High-Frequency over-the-horizon (HF) radars currently consisting...
The majority of High Frequency (HF) radars used worldwide operate at medium to high frequencies (8 to 30 MHz) providing spatial resolutions ranging from 3 to 1.5 km and ranges from 150 to 50 km. This paper presents results from the deployment of a single Very High Frequency (VHF, 48 MHz) WEllen RAdar (WERA) radar with spatial resolution of 150 m and range 10-15 km, used in the nearshore off Cape Hatteras,...
A coherent marine radar with 3-m resolution has been developed that measures the radial component of the orbital wave velocity of ocean waves, as well as the mean radial ocean surface velocity. This radar provides a direct measure of the ocean wave spectrum by means of 3D-FFT processing of a sequence of radial velocity images collected at a 0.8 Hz image rate. Typically, 512 images are used, covering...
Data from CODAR-type ocean current sensing radar systems are used here to evaluate the performance of an error indicator provided as part of the available radar data. Investigations are based on data from pairs of radar systems with over-water baselines. Approximately year-long time series are used. The radar data are the typical hourly radial measurements provided by CODAR systems. These measurements...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.