Ocean & Coasts: Multibeam Sonar
Sonar system is use to locate and identify underwater objects. This equipment sends beam of sonar all the way to the ocean floor and it measure the amount of time it takes for the beam to bounce back to the ship. The sonar creates sound pictures or map of the floor in 3-D. The ship was testing the sonar of the coast of California and what they found is that the sound bounced off gas in the water column that create an image of a gas plume that rose 4,600 feet from the ocean floor. The sonar was first used during WWI so submarines can detect others submarines. Scientist use two types of sonars: Active and Passive. The active sonar sends an acoustic signal or pulse of sound into the water. It measures the of the signal when it receives them. Also the Active sonar what if does when an object is in the parth of the sound pulse, the sound bounces back off the object and creates and "echo" sound to the sonar transducer. The Passive sonar detect noise from marine objects like ships, marine animals like whales, and submarines. The Passive sonar is not like the Active sonar, also what it does it only detects sounds waves coming towards it. The Passive cannot detect an object like the Active sonar does. Scientist also uses "Side- Scan", what it does also detect object on the ocean floor. The sonar requires 3 components: A towfish that sends and receive acoustic pulse, A transmission cable that is attached to the towship and it send data to the ship. And the ship's processing computer.