Acoustic Tide Gage

Detailed Description
The sensor and vent head of an acoustic type tide gage at USGS 01409125 Barnegat Bay at Barnegat Light, New Jersey.
Acoustic water-level sensors emit sound waves that travel through the air in a contained pipe and bounce off of the water’s surface. The water elevation is calculated based on how long it takes for that sound wave to be received back by the sensor along with the velocity of that sound wave, which is dependent on temperature. For this reason, they are also equipped with their own water and air temperature sensors. Thes data are averaged using an NOS averaging algorithm and logged as 6-minute readings.
Sources/Usage
Public Domain.