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SONAR, as it is most commonly known as has been around since the beginning of time. Animals have used this technique and survived because of it for millions of years. Among the most common are bats and dolphins.
Daniel Colloden used a bell to measure the speed of sound underwater in 1822. After the Titanic sunk, the idea of using sound underwater to locate objects, primarily icebergs, was taken up by inventors. Lewis Richardson, a meteorologist, was the first to file a patent for an echo locator one month after the Titanic had sunk. In 1914, Reginald Fessenden made an experimental unit, which was able to detect icebergs within a two-mile range, but it could not determine the direction.
During World War I, with the invention of submarines came the need to locate them. Research of underwater sound location was a primary focus for the British. Both the U.S. and Britain were researching what would be Sonar, and it was kept secret throughout the war. By 1922, units were being produced and by 1923, they were being equipped to naval vessels.
Throughout the war, Britain referred to this underwater locator as ASDIC, which was the Anti-Submarine Detection Investigation Committee. This committee, however, never existed. The name was just a cover-up to keep the actual detector secret. The term SONAR came from the Americans, who used it as the equivalent of RADAR. The term ASDIC was terminated in 1948 when NATO was formed and signals were being standardized.
Sonar utilizes sound propagation to detect objects, navigate, and communicate. Through acoustic location, Sonar can be used to find an object and tell how far away that object is.
As shown above, a transmitter sends out a pulse of sound towards an object, the sound wave is then reflected off of the object and sent back to the source.
The distance of the object is determined by the amount of time it takes for a reflection to return after the pulse is sent out. This can be affected by several factors such as the density of the media which the sound is traveling through and if the object itself is moving or not.
To find the direction of the object, several receivers are used to signal when a reflection passes by them.
The above picture shows an initial wave being sent out in all directions.
The Project Office was created in 1982 and a contract with the Australian Submarine Corporation Pty Ltd (ASC) was signed in June 1987. The first submarine, HMAS Collins, was launched in August 1993. This was a significant achievement for ASC and its subcontractors given that the production program commenced at widely separated sites in 1987 and ran in parallel with design and system development (ANAO, 1998).
Archaeology is a continuously evolving field where there is a constant stream of new branches and excavation methods. Due to the influx of new technologies and innovations in recent decades, archaeologists have been able to excavate previously inaccessible areas. For example, new diving equipment and tools such as proton magnetometers, side-scan sonar, sub-bottom profiler, and miniature submarines have allowed archaeologists to dive into the deep depths of the ocean. As a result, the branch of underwater archaeology was created to search for shipwrecks and other artifacts on the ocean floor. Underwater archaeology’s role has increased in recent years as it allows archaeologists to more accurately interpret the past by supplementing information gained through traditional land excavations.
Throughout the years submarine technology has advanced throughout the years from the original military submarine the turtle to the German u boats during WWII modern nuclear power submarines that we have today. These developments have required a lot of technological improvements. To make the u boats work the Germans need better battery and electrical motor technologies and the nuclear submarine obviously needed nuclear technology. Submarines have always been an innovative way to win the navel war.
Both the Britain and Germany made substantial scientific developments throughout the course of the war. Prior to the development of the Lancaster, the British Air Force lacked a long-range bomber, capable of carrying substantial bomb loads. Wattson Watt foresaw the need for an early detection system; he developed the 'Radiolocation' system, which alerted Britain to invading forces. The German Air Force developed an on board radar, called the 'Metric system', which was equipped to German night fighters.
...t was not for these precursors then the continuation of unrestricted submarine warfare might still be a threat to the vessels that now transport hundreds of thousands of people all over the globe.
The weapon was designed to lock onto the loudest noise after a run of 400m from its launch. This often proved to be the U-boat itself and standard issue-orders were to dive immediately to depth of 60m after launch from a bow tube while a stern shot was to be followed by a complete silence in the boat. Two U-boats were almost certainly lost when hit by one of their own T5 torpedoes, U-972 in Dec 1943 and U-377 in Jan 1944.
If you put your finger gently on a loudspeaker you will feel it vibrate - if it is playing a low note loudly you can see it moving. When it moves forwards, it compresses the air next to it, which raises its pressure. Some of this air flows outwards, compressing the next layer of air. The disturbance in the air spreads out as a travelling sound wave. Ultimately this sound wave causes a very tiny vibration in your eardrum - but that's another story.
Ultrasounds use the same concepts that allow sonar on boats to see the bottom of the o...
internal structures of the body and returned to the transducer. The transducer converted the returning sound into electronic signals that were processed
Unless you travel into the vacuum of space, sound is all around you every day.. You hear sounds; you don't touch them. But as the vibrations that sound creates in other objects. The idea that something so intangible can lift objects can seem unbelievable, but it's a real phenomenon.
Hackmann, Willem Dirk. “SONAR.” Encyclopedia of World War II. Vol. 2. New York: Facts on File, 2007. Modern World History Online. Web. 21 Mar. 2012. .
Many contributions have been made to the development of radar over the years. For many years prior and during the Second World War, radar was considered a top-secret military tool. Once it was made public, people used the existing radar information to come up with their own variations for different applications. As a result, the true origin of radar has become blurred within conflicting claims. Radar can be traced back as far as 1832 when British physicist Michael Faraday suggested the existence of an electromagnetic field between certain objects from his scientific observations.
3. Brain, Marshall, and Tom Harris. "How GPS Receivers Work." 25 September 2006. HowStuffWorks.com. 01 June 2010.
Most people have some sort of familiarity with submarine crafts; most of which are most likely related to the navy. This is a very accurate depiction of submarines, as they are primarily used for this, however, they are used in areas of scientific research as well. The purpose of this web page is to go into the history of the submarine to see how it has developed over time. We will also look at how a submarine works, from a physics standpoint.
The carbon transmitter uses carbon granules between metal plates called, electrodes, with one consisting of a thin diaphragm that moves by pressure from sound waves and transmits them to the carbon granules. These electrodes conduct electricity flowing through the carbon. The sound waves hit the diaphragm, causing the electrical resistance of the carbon to vary. The electronic transmitter is composed of a thin disk of metal-coated plastic held above a thick, hollow metal disk. This plastic disk is electrically charged, and creates an electric field.