2006-12-12 22:15:52 · 7 answers · asked by Anonymous in Education & Reference ➔ Words & Wordplay
These explanations are basically correct.
It was discovered by a Herr Doppler (German or Austrian) in the 19th. century. He noticed sounds of horns, or whatever, from passing firecarts were bouncing back from the walls of buildings.
This led him to research sound waves.
2006-12-12 23:11:15 · answer #1 · answered by cloud43 5 · 0⤊ 0⤋
Ultrasound is generally not used for navigation
Radar is used for navigation, GPS is used for navigation
Sonar (ultrasound) is directed underwater, and is used to detect the depth of a channel, shipwrecks and shoals of fish for trawlers.
In sonar devices, a sonic transducer sends out a pulse of sound. this is relfected back and received. Distance can be calculated from the time taken between the sent pulse and the received pulse.
Radar works in much the same way in air, except the pulse is an electromagnetic (microwave) pulse
2006-12-12 22:33:25 · answer #2 · answered by Vinni and beer 7 · 1⤊ 0⤋
It is directed to the obstacle. When it reaches the obstacle and reflects of it it returns back to the special catching device on the ship. Given the time required for the sound to pass a certain distance the device calculates the distance remaining to reach that obstacle.
2006-12-12 22:18:18 · answer #3 · answered by Amelisa 1 · 0⤊ 0⤋
the speed of sound in water is about 1482m/sec
the ship sends out a signal and recieves the same signal reflected from its target (another ship, for example) one second later.
This means the sound has travelled 1482 metres which is 741 metres there and 741 metres back.
the other ship is therefore 741 metres away. (well it was, one second ago)
2006-12-12 22:29:49 · answer #4 · answered by eurobuskers 2 · 0⤊ 0⤋
sounds are sent out from the ship and when it hits an obstacle in the way it sends a signal back and you can tell how far they are then
2006-12-12 22:21:03 · answer #5 · answered by Craig C 2 · 0⤊ 0⤋
In Naval parliance ultrasound is in fact referred to as "sonar".
2006-12-12 22:59:30 · answer #6 · answered by Anonymous · 0⤊ 0⤋
essexfriendly has the most complete and correct answer
2006-12-15 02:08:05 · answer #7 · answered by yankee_sailor 7 · 0⤊ 0⤋