High Frequency Radar

Scientists have recognized high-frequency radar (HF radar) as an effective tool for measuring the speed and direction of ocean surface currents. The broad range of uses for this information on currents has motivated the development of a national network of surface current mapping systems as part of the U.S. Integrated Ocean Observing System (IOOS). Dozens of institutions own and operate HF radars within the United States, and most are coordinated through U.S. IOOS. Ocean surface current data from these radars are shared on national servers—National Data Buoy Center and Scripps Institution of Oceanography—that deliver the data to anyone who needs it. For more information on the national system of radar stations, read the IOOS report. So why should ocean planners pay attention to where HF radars are located?

  1. HF radars measure the speed and direction of ocean surface currents in near real time. These radars can measure currents over a large region of the coastal ocean, from a few kilometers offshore up to 200 kilometers, and can operate under any weather conditions. They are located near the water’s edge and need not be situated atop a high point of land. Accurate measurement of surface currents and waves is critical to a range of ocean planning applications, including but not limited to tracking and predicting oil spills, assessing shoreline erosion, and providing maritime forecasts of currents and waves to recreational and commercial communities. These applications require access to densely distributed, near-real-time, current measurements.
  2. Locations of offshore wind farms may interact with the effectiveness of the radar systems. Data users must understand where the radars are located so that any potential impacts to data quality can be mitigated. Simulation studies to evaluate impacts have been completed. U.S. IOOS has recommended to the Department of Energy that further studies be carried out to further quantify, and assess methods to mitigate these impacts.

Quick Caveats. This data set shows the point locations of HF radar systems across the U.S. The IOOS community has developed a process to define the spatial footprint of each radar by including local factors such as nearby obstructions (both man-made and natural), local wind-wave environment, etc. Maps of these footprints can be viewed on the IOOS website.

Data‐Expert Sources
For technical questions about the HF radar data, or if specific information regarding a radar system is required, please contact Derrick Snowden (, Operations Division Chief, U.S. IOOS Program Office.

For questions, please contact