High-Frequency Radar

Researchers at the University of Alaska Fairbanks (UAF) are using high-frequency radar (HFR) systems along portions of the Alaska coast to generate real-time spatial maps of surface ocean currents. Located in the western Beaufort-Chukchi Sea region and central Cook Inlet, HFRs are the only land-based sensors capable of measuring large-scale ocean surface currents in detail.

A transmit antenna sends out radio waves over the surface of the ocean, and a paired receiver antenna collects the signal that is bounced back by the ocean waves.The received signal is shifted by a process known as the Doppler effect. This same principle is used by a policeman using a radar gun that informs how fast a car is moving. The reflected signals are then used to produce spatial images of water flow speed and direction.

In near real-time, the CFOS data are integrated into IOOS’s HFR National Network and shared through the AOOS Data Portal. This publicly available resource supports marine navigation, search and rescue, marine forecasting, and oil spill response. Combined with observations from local communities, these maps provide a more complete understanding of the marine system.

Explore Further

• IOOS HFR website
  https://ioos.noaa.gov/project/hf-radar/
• UAF College of Fisheries and Ocean Sciences website
  https://www.uaf.edu/cfos/
• NOAA IOOS HF-Radar Network
  https://hfradar.ioos.us/hfrnet/
• UAF CFOS Chukchi Sea Surface Currents website
  https://research.cfos.uaf.edu/hfradar/