Technologies

Principle

Shortwave marine radar system receives ”Bragg resonant scattered waves'', which are the interaction of surface-propagating HF-band radio waves with waves that shape the surface of the ocean. From the analysis of the received signals, it is possible to clarify the speed and direction of the surface currents, as well as the height of waves, which change from moment to moment.

Software defined radio technology (SDR) to generate accurate waveforms 

Scattered waves from the sea surface, which are received by direct conversion, are seamlessly transferred to Digital Signal Processing and to Doppler Spectrum Calculation at the subsequent stage. 

Digital Beamforming and Array Processing

Formation of extremely stable directional characteristics, enabled by these two technologies, Digital Beamforming and Array Processing, make it possible not only to measure current velocity but also to measure wave height and wave direction. We will also utilize Direction-of-arrival estimation technology, MUSIC, etc., and work on reducing the array size, for the purpose to reduce the size of installation area.

Land-based oceanographic observation

Although it is a marine observation system, our system is installed on land. Thus, maintenance is so easy, and observation can be continued even when the sea becomes rough due to stormy weather. This will make the cost efficiency of operation and maintenance much higher than any other observation system, which count on the Ocean Buoys, Aircrafts and Satellites. 

Continuous monitoring with a “Short-term Monitoring mode” option

Our system is basically designed to spend a long time to monitor continuously changing situations of the surface of the sea to calculate the reliable figures of current velocity and direction. However, whenever such a need arises that requires a quick monitoring under some unusual situation, such as river floods or Tsunamis, the system can be switched to a short-term observation mode that outputs data in units of minutes.

Status Prediction by Model Linking 

As the dense observation data stock obtained in our radar system can be successively assimilated at the time of actual data calculation all the time, we will be able to constantly improve the accuracy of our real-time output. We will also try to utilize this mechanism to develop and enhance our “future prediction” capability.