CeNCOOS
central and northern california ocean observing system
Ocean Surface Currents| How it Works | Coverage | COCMP Program | National Archive | Contact COCMP |
 

How it works
We measure ocean currents by emitting radio waves from shore-based transmitting antennas that travel along the ocean's surface. The radio waves are scattered by the rough surface of the ocean (ocean waves) and part of the scattered energy returns like an echo to a receiving antenna.



The received echoes contain information about the range, direction, and speed of the current in relation to the antenna location. Combining this information from two or more antennas allows us to construct surface maps of current speed and direction.

 

Radio Frequencies
Athough the technology we use to measure ocean currents is typically called "High Frequency Radar" of "HF Radar", a more accurate name is "HF Radio". Ocean current transmitting antennas operate at similar frequencies to broadcast radio and TV, but at much lower power levels (0.1% or less). The transmitted energy, comparable to the power of a household light bulb, is harmless to humans and animals.

 

Additional Information
For more information, please visit the following websites:

     
     
 
Ocean currents maps are a product of the Coastal Ocean Currents Monitoring Program (COCMP). The project is funded by the State of California from the California Clean Water, Clean Air, Safe Neighborhood Parks, and Coastal Protection Act of 2002 and the Water Security, Clean Drinking Water, Coastal and Beach Protection Act of 2002.