PLANET OCEAN LTD INTRODUCES: THE RADAC WAVEGUIDE RADAR

Described by the European Commission in 2008 as 'the energy of the future', the re- sulting growth in the offshore wind industry helps to ensure security in Europe’s future energy and a transition into a low carbon economy. Weather however remains a major risk to offshore operations and knowledge of site conditions assists in determining the optimum times during which certain procedures can be performed safely. While ad- vances in technology and industry maturity will make offshore wind an increasingly attractive investment, the industry is always in need for solutions which reduce costs and increase operational efficiency. Since 1996, RADAC has therefore been developing the WaveGuide: a very accurate radar based system to measure the sea state, vital in planning operational and development activities in the offshore environments. Wave and tide data are of great importance during all stages of offshore wind farm development and operation as well as many other sectors. Vessels, such as those used for jacking operations, crane operations and towing, rely on real-time wave data. Their operations are typically limited by a maxi- mum wave height of two meters or less. Therefore reliable and real-time data are essential for maximised exploitation of weather windows and improved safety during these offshore activities.

From the development phase onwards, wave data is required to calculate the wave load in order to define the requirements of the platform design. In addition, during its operational life, the actual wave climate is monitored to validate the expected endurance models and justify the lengthening or shortening head and which facilitates commissioning, remote servicing, for the platforms lifetime. Accurate analysis of the possible data collection, data processing, presentation and logging. It exploitation period can make an enormous difference in cost. incorporates an internal web-server so that any web enabled Over the past 40 years the standard method for obtaining device connected to the same network can access the wave wave information is by the use of wave directional buoys. The data without the requirement for special software or hard- main advantage of using a buoy is its independence from sup- ware. port structures. However the disadvantages of this method The WaveGuide comes as standard in four different models, include the high maintenance costs and the risk of long peri- differing in functionality from simple water level to a system ods without measurements when a buoy breaks from its which measures all directional wave parameters. mooring or runs out of power. Buy based system are also ex- tremely expensive to deploy and recover for servicing. Wave Direction

Down-looking Frequency-Modulated Continuous Wave RADAC’s showpiece is the WaveGuide Direction. The direction- (FMCW) radars for wave measurements have been used for 25 al system consists of three downward-pointing radars. With an years. The popularity of these systems have grown as prices array of three radars, the elevations of the sea surface is for FMCW radars have fallen and the increased use in the field measured at three positions. Knowing the slopes and the have proven them to be a very robust and low maintenance phase relations, the directional spectrum can be accurately alternative to buoy systems. As such, they are slowly becom- calculated. RADAC is the only company that brings this tech- ing a preferred method for collecting environmental data, and nology to the market. are now more widely applied for water level, tide, harbour RADAC has conducted field trials at Prinses Amaliawindpark, oscillations and wave direction and height at sea. 25 kilometres off the Dutch coast. Two versions of the Direc- The WaveGuide tional WaveGuide were compared to a Directional Waverider buoy over a period spanning several months. The field trials RADAC supplies systems for remote monitoring waves and successfully indicated no statistical difference in the direction- tides, including wind farms and installation vessels. The RADAC al information from the buoy and from the WaveGuide radars. WaveGuide is an accurate radar system introduced in 1996, incorporating advanced technologies that make it an easy to use, reliable and robust device for measurement of level, tide and waves up to the most extreme conditions.

The WaveGuide radar measures the distance to the water sur- face several times per second. Mounted high above the water with no moving parts, preventive maintenance or cleaning is not required. The system is compact and easy to install, suited to accurately measure wave direction, heights and tides in all Therefore, the Directional WaveGuide can not only accurately weather conditions. Recalibration is also never required due to and reliably measure wave direction, but the high quality data the long-term stable zero reference. is achieved without the hassle of service operations and break away buoys. The WaveGuide control system (data server) is a small low powered module that can be located distant from the sensor Onboard break waters, not only to determine construction require- ments but also to monitor changes in wave climate. Real-time The same technology can be applied directly to vessels to aid measurements are also useful for safe vessel guidance and in their operations. The WaveGuide Onboard installation com- (un)loading of ships. pensates for the vertical motions of the ship, so it measures the waves the ship actually has to endure. A significant ad- Additionally, collecting data provides insight into natural phe- vantage of the WaveGuide Onboard is the continuous availa- nomena and patterns. This aids in predicting water levels in bility of wave data, especially at night, in rough seas and under the future, increasing peace of mind. Especially where the heavy weather conditions with limited visibility. river flows into the sea, extremely high water levels during storm conditions can cause flooding. Additionally, the WaveGuide Onboard measures the waves as they are encountered by the ship itself. This data is ideally Besides the danger of flooding, the lack of water is equally used to determine the operational limitations of the vessel in important. In those situations water level information is cru- harsh conditions. Therefore, a vessel in transit can adjust its cial to water distribution planning. River water level data is speed and course to avoid critical headings. This not only helps essential for shipping as it influences safe passage of vessels to identify safe heading and speed, but also monitoring the (sea gauge/river clearance). actual wave load to determine the lifetime of the vessel. In areas such as coastlines, harbours and deltas, various natu- ral phenomena occur including waves, tides, storm surge, tsu- As the distances measured have to compensate for the verti- nami and harbour oscillations. Despite this diversity, all are cal motions of the radar itself, a motion sensor is incorporated accurately measured by the WaveGuide, without interfering into the sensor unit. The WaveGuide Data Server takes care of with harbour traffic. synchronisation, collection and compensation of the data col- lected. The compensated radar signal is processed in the same way as the standard WaveGuide mounted on a fixed platform. Using the available “Wave and Tide Processing Software” raw data, spectra and parameters can be requested and presented on the web browser. Other Applications

It has been and will be important to warn for flood risk due to storm surge, especially as a result of the rise in sea levels. Ad- ditionally, it is of great importance for coastal defence and harbours to monitor actual stress levels on dikes, dunes and ABOUT RADAC

RADAC are a fast growing Dutch company, based in Delft. RADAC has a young en- thusiastic team, with a vast range of knowledge combining oceanography, physics and radar technology. By working with the clients in new projects, they develop their products in real live situations as well as working closely with the Technical University of Delft, Deltares and others.

They are proud that professional systems have gained industry-wide trust and recognition. Their client base is made up of oil companies, offshore wind farm oper- ators, port operators, governments, shipping companies and international project developers.

One of their valued customers is the Dutch Directorate-General for Public Works and Water Management (Rijkswaterstaat). After a thorough evaluation spanning several years they adopted the WaveGuide System as the water level and wave height sensor in their primary measuring network. For wave height Rijkswaterstaat uses the SWAP program, which meets the strict standards of oil and gas companies (IOGP).

RADAC – ReliAble Durable Accurate PLANET OCEAN LTD

Planet Ocean is proud to represent some of the world’s leading scientific instrument manufacturers and we bring you the very best from each of their specialist areas of expertise.

We are also able to provide bespoke and specialist systems not shown here; please contact us with your special project re- quirements.

For more information please contact us at [email protected]. Acknowledgements

Katja Roose, Marketing & Sales, RADAC