Echo sounders are classified into two types. These are the single-beam echo sounders(SBES) and the multi-beam echo sounder(MBES)
Single-beam echo sounders were initially developed around 80 years ago and were used instrumentally for primary oceanic discoveries and standardization. It is also known as a fathometer or depth sounder. It works on a single sound pulse in a single narrow beam and can only measure one point per echo.
Nowadays, SBES is used for depth measurements, sub-bottom observations, and seabed imaging.
Other SBES are defined by their beam angle and frequency of transmitted sound waves. Water depth capabilities of single-beam echo sounder range from less than one meter to full ocean depth.
The second type of echo sounder is the MBES or the multi-beam echo sounder. It emits a multidirectional beam to obtain information in the affected area. The sound waves received back by the transducers provide detailed information on the depth of water, the shape of the river, lake, and other underwater features.
This information is used by Geological survey companies to accurately generate high-resolution maps of harbors, berthing terminals, lake bottoms, and channels used for navigation.