Until 1996 the University of Hamburg HF-Radar group has been using a modified CODAR , which e.g. did not allow access to the second-order sidebands in the Doppler spectrum. To overcome these limitations, a new HF-radar we named WERA (WEllen RAdar) has been designed to allow for a wide range of working frequencies, spatial resolution, and antenna configutarions. The main advantages of WERA include:

• Simultanous measurement of current and wave maps.
• Different receiving antenna designs (4 to 16 antennas) in combination with direction finding and beam forming techniques for azimuthal resolution. Here is a picture of the 16-element linear array(set up on the dike at Petten.), which is needed for ocean surface current and wave measurement and this picture shows the 4-element square array(set up at the beach near Ahlbeck.), which can be used for ocean surface current measurement only.
• Frequency chirp continuous wave modulation (FMCW)
  • to avoid a blind range in front of the radar,
  • to simply modify the radar's range resolution down to 300 m,
  • to reduce the impact of radio interference.
• The radar is linked to a Unix workstation for data management and processing.
• 90% of the signal processing steps are implemented in software and thus can be modified or updated in a simple way.
• WERA is a very modular design, which can be easily adopted to different applications.

Examples

• This is an example showing a coastal jet in front of the Dutch coast at 1.2 km resolution mode. An area up to 50 km off the coast can be covered.
• A similar situation measured at 300 m resolution mode can be seen in this example.

Related projects

• Measurements of waves and currents at the Dutch coast (SCAWVEX)
• European Radar Ocean Sensing (EuroROSE)

WERA System Characteristics