10.7.2. Echo Sounders and Sonars

Try these first

1. 1.

   What does an echo sounder measure?

   Hint

   Think about instruments used for navigation.

2. 2.

   Name one type of sonar.

   Hint

   Consider the technology that provides images of the underwater terrain.

3. 3.

   What technology is used by echo sounders to measure depth?

   • Light pulses
   • Sound pulses
   • Radio waves

   Hint

   Think about what travels well underwater.

4. 4.

   True or False: Multi-Beam Echo Sounders provide a single depth measurement.

   • True
   • False

   Hint

   Consider the meaning of 'multi' in this context.

5. 5.

   If an echo sounder sends out a pulse and it takes 3 seconds for the echo to return, what is the depth of the water (assuming the speed of sound in water is 1500 m/s)?

   Hint

   Remember to divide by 2 since the sound has to travel to the bottom and back.

6. 6.

   How would choosing a Single Beam Echo Sounder over a Multi-Beam Echo Sounder affect your data collection during a survey?

   Hint

   Think about the scanning coverage of each device.