Helzel Messtechnik GmbH

Kaltenkirchen, Germany

Helzel Messtechnik GmbH

Kaltenkirchen, Germany

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Helzel T.,HELZEL Messtechnik GmbH | Kniephoff M.,University of Hamburg | Petersen L.,University of Hamburg
Turkish Journal of Electrical Engineering and Computer Sciences | Year: 2010

The WERA system (WavE RAdar) is a shore based remote sensing system to monitor ocean surface currents, waves and wind direction. This long range, high resolution monitoring system based on short radio wave radar technology. The vertical polarised electromagnetic wave is coupled to the conductive ocean surface and follows the curvature of the earth. This over the horizon oceanography radar can pick up back-scattered signals from the rough ocean surface (Bragg effect) from ranges of up to 200 km. The physical background, technical concept and environmental boundary conditions are explained. Results for various installations from all over the world demonstrates the features and flexibility of the system: high resolution monitoring (range cell size of 300 m) over a range of 60 km or long range applications with 3 km range cell size, all generated with the typical high temporal resolution of 10 minutes. The technical performance depends on the site geometry, system configuration and the environmental conditions. These aspects are discussed to enable interested users to estimate the potential of this technology for their specific application.


Heron M.,James Cook University | Dzvonkovskaya A.,Helzel Messtechnik GmbH
OCEANS 2015 - MTS/IEEE Washington | Year: 2015

Recently published data from a WERA phased array radar operating in Chile after the Great Tohuku Earthquake in 2011 show that the tsunami lost a significant amount of energy as it shoaled towards the coast. This experimental result was contrary to that from the linear theory often used to estimate amplitude growth during shoaling. This paper evaluates the reflection of energy from a bathymetric step that might represent the edge of a continental shelf. A geometric wave approach is used to evaluate coefficients of reflection and transmission at the refractive index boundary. It is shown that reflection can explain some, but not all of the difference between linear theory and observations. © 2015 MTS.


Heron M.,James Cook University | Dzvonkovskaya A.,Helzel Messtechnik GmbH | Helzel T.,Helzel Messtechnik GmbH
MTS/IEEE OCEANS 2015 - Genova: Discovering Sustainable Ocean Energy for a New World | Year: 2015

Recent reports have shown high-frequency (HF) radar measurements of tsunami signatures as the disturbance propagates from deep water to shallow water across the edge of the continental shelf. Most HF radars are optimised in various ways to measure seasonal circulation, tidal currents or sub-tidal structures. The new data provide the basis for the design of an optimised HF radar installation for the purpose of monitoring tsunamis and issuing accurate warnings to coastal communities. The optimised system has a long range capability, and it has time and space resolutions to match the features that appear in the expected range for tsunamis. © 2015 IEEE.


Dzvonkovskaya A.,Helzel Messtechnik GmbH | Heron M.,James Cook University | Figueroa D.,University of Concepción | Gurgel K.-W.,University of Hamburg
2014 Oceans - St. John's, OCEANS 2014 | Year: 2015

A WERA phased array HF radar was used in Chile to observe the disturbance of the 11 March 2011 tsunami which originated near Japan. In this pilot study, three sites on a transect across the shelf were analysed at water depths of 40, 160 and 880m. The maximum wave orbital velocities increased as the wave-group propagated into shallow water. The increase in maximum wave orbital velocities between 160 m depth and 40 m depth followed linear theory, but between 880 m and 160 m depths, the tsunami wave-group was non-linear and over half the amplitude was lost. The HF radar data indicate that non-linear processes are occurring at this location as the tsunami disturbance propagates from deep water onto the continental shelf. © 2014 IEEE.


Heron M.L.,James Cook University | Prytz A.,Balagorang Pty Ltd | Gomez R.,Helzel Messtechnik GmbH | Peters H.,Rijkswaterstaat
OCEANS 2016 - Shanghai | Year: 2016

The phased array HF ocean radar installed at the Port of Rotterdam gives good quality near real-time information on surface currents for port management. This paper examines the potential to infer current profiles from HF radar and wind station data using prior knowledge of the site. It is shown that tidal currents follow a logarithmic boundary layer profile, and the wind-driven currents have an approximately exponential profile. These two models are combined to estimate the current profiles. © 2016 IEEE.


Dzvonkovskaya A.,Helzel Messtechnik GmbH | Rohling H.,TU Hamburg - Harburg
2014 International Radar Conference, Radar 2014 | Year: 2014

The high-frequency (HF) surface wave radar system located at the coast is well-known as a tool for synoptic on-line mapping of sea surface current fields and the spatial distribution of the sea waves. Especially for oceanographic applications, low power HF radar systems have been developed, which use surface wave propagation along the salty sea surface. Such HF radar system brings area surveillance far beyond the conventional microwave radar coverage. Additional options for oceanographic radar applications can be vessel and aircraft monitoring above sea surface. This paper describes a new attempt in signal processing approach for detection of fast-moving targets in the radar observations based on a constant false-alarm-rate algorithm. The target locations detected by the HF radar are passed to a tracking filter using range and azimuth information to track the locations of fast-moving targets. A special short coherent integration time mode has been applied for processing real radar measurements. The tracking procedure is performed for fast-moving target observation using two monostatic HF radar systems located at the coast. © 2014 IEEE.


Dzvonkovskaya A.,Helzel Messtechnik GmbH | Helzel T.,Helzel Messtechnik GmbH | Petersen L.,Helzel Messtechnik GmbH | Gill E.,Memorial University of Newfoundland
OCEANS 2015 - MTS/IEEE Washington | Year: 2015

HF ocean radars are usually installed along the coast and deliver remote sensing information by transmitting a radio signal with an operating frequency between 3 and 30 MHz. The frequency band allows for a large coverage of ocean surface that could extend more than 200 kilometers offshore depending on the transmit frequency and other operating conditions. To provide a dense coverage of the sea surface, the installation of ocean radars in a radar network may require that the transmitting and receiving units of a radar network demand time synchronization between the units to perform correct space-time measurements of ocean parameters. In this paper, a self-organized synchronization for HF ocean radars is considered without the use of Global Positioning System (GPS) devices. In the case of multiple transmitters, the power peaks are observed in spectra simultaneously for each of the transmitters; hence the time shift can be estimated separately for each of them. The self-organized approach is very useful for the case of multiple transmitters and receivers in a radar network as well as in multiple-input-multiple-output (MIMO) radar configurations, which utilize the feasibility of occupying less space for a HF radar receive antenna while maintaining the high spatial resolution of the radar data. © 2015 MTS.


Helzel T.,Helzel Messtechnik GmbH | Petersen L.,Helzel Messtechnik GmbH | Mariette V.,Actimar | Pavec M.,Actimar
Journal of Coastal Research | Year: 2011

The WERA system (WavE RAdar) is a shore based remote sensing system to monitor ocean surface currents, waves and wind direction. The outstanding temporal resolution of this systems allows to monitor very dynamic processes on the ocean surface, such as small scale Eddy currents, wind induced currents and wave fields. Due to the shore based installation the availability of the data is very high even under harsh environmental conditions. Validation studies from various installations demonstrate the accuracy of these systems. The typical correlation of the surface current velocity measured with the radar compared with an ADCP measurement is better than 0.9. The correlation of the wave height measurements compared with wave buoys come close to these values. Statistics from permanent installations demonstrate the extreme high data availability (reliability) of this shore based instrument, during the last three years the system provided 98.7% data for all pixels of the ocean surface near Brest (France) within an area of 40 × 40 km. This high accuracy and outstanding reliability makes this ocean radar a perfect tool for coastal zone management. Combining these accurate real-time data with numerical ocean models allows to generate very reliable forecasts of the trajectories of drifting objects like persons, containers or oil spill. This makes these instruments a valuable tool for hazard management.


Helzel T.,Helzel Messtechnik GmbH | Kniephoff M.,Helzel Messtechnik GmbH | Petersen L.,Helzel Messtechnik GmbH
2006 IEEE US/EU Baltic International Symposium, BALTIC 2006 | Year: 2016

The WERA system (WavE RAdar) is a shore based remote sensing system to monitor ocean surface currents, waves and wind direction. This long range, high resolution monitoring system based on short radio wave radar technology. The vertical polarised electromagnetic wave is coupled to the conductive ocean surface and will follow the curvature of the earth. This over the horizon oceanography radar can pick up back-scattered signals (Bragg effect) from ranges of up to 200 km. Results for various installations from all over the world will demonstrate the features and flexibility of the system: high resolution monitoring (range cells of 300 m) over a range of 60 km or long range applications with 3 km range cell size, all generated with the typical high temporal resolution of 10 minutes. The quality of the resulting data does not depend on the high technical standard of the WERA system only but on the site geometry and environmental conditions as well. These aspects will be discussed to enable interested scientists to estimate the potential of this technology for their specific application. © 2006 IEEE.


Dzvonkovskaya A.,Helzel Messtechnik GmbH | Helzel T.,Helzel Messtechnik GmbH
Proceedings International Radar Symposium | Year: 2015

In the wider maritime environment there is an increasing requirement of continuous maritime surveillance in all-weather conditions. This challenge can be well solved by using high-frequency (HF) ocean radars installed at the coast. These systems are capable to monitor sea surface far beyond the horizon and deliver information about sea state parameters and vessel tracking. Performance of the WERA HF ocean radar systems was analyzed for both oceanographic and vessel tracking applications under adverse meteorological conditions during severe storm Xaver, which crossed the German Bight on December 5-6, 2013. The results showed that radars survived the storm and were providing measurements continuously. The radar coverage was reduced suitably in range during the storm to give adequate measurements of sea surface current velocity. The sailing vessels were identified in strong variable sea clutter caused by wave heights up to 8 meters. © 2015 German Institute of Navigation (DGON).

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