In the early stage of sonar technology development, Sonar can be more accurate described as echo locate. Generally, the sonar system propagates acoustic signal and the echo is detected. By processing and calculating the received data, the distance from the transmitter and the object detected reached.
Sonar can be divided into active sonar and passive sonar.
Passive sonar is more like a listener or so called ‘hydrophone’. Passive sonar does not propagate any signal but receives the acoustic signal from the environment to identify the objectives.
Active sonar share the same working progress like radar, it propagates acoustic signal and detect the reflected signal to identify the distance and the direction of the detected object.
History of
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Actually, Sonar technology, precisely speaking, echo locating was first to be found used by bats.
Research on animal sonar can be traced back to the work of the Italian scientist Lazzaro Spallanzani in the 1770s. He observed that bats could fly freely in a dark room where owls were helpless. He was amazed to observe that bats that had been blinded could fly and avoid obstacles as well as those that could see. Then, a Swiss scientist Jurine found that the bats became helpless and collided with obstacles with ears waxed. He concluded that the bats’ hearing was an important component of the bats’ orientation and obstacles avoidance capabilities.
The history of sonar is very ambiguous because there is much research in the familiar fields like echolocation. Until 1906, the real first sonar system was invented by Lewis Nixon of UK Royal Navy. It is a passive sonar system used to detecting iceberg. This technology is first used in battle field during the First World War to detecting submarines. Two years later, the prototype of the first active sonar is developed by a Canada physicist Robert Boyle of Anti/Ailled Submarine Detection Investigation Committee and sonar was first called ASDIC.
The first mature sonar system was invented at 1918 by UK and US
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Once these sounds hit an object, echoes are created. The dolphin then listens to these echoes and is able to form a kind of material image of the object. A dolphin produces these click sounds using a structure in its head called the phonic lips. Since dolphins have two sets of phonic lips, they are able to produce two sets of click sounds simultaneously. This means that they can produce two sets of click sounds simultaneously, as well as whistle sounds which are produced in the larynx. Dolphins are great multi-taskers when it comes to sound
waves were reflected back to the transducer as they crossed interfaces of different acoustic impedance. More simply, the ultrasound bounced off the
In Chinese tradition, Shark fin soup is called as “a celebration soup”, which people eat it to celebrate in various occasions. Moreover, people also believed that shark fin consisted of diverse nutrition values which provide them virility, wealth, and power(Wolchover, 2011). These beliefs lead to the beginning of poaching for sharks, the top of food chain in the sea world. Surprisingly, although people are aware of the decreasing number of sharks since the old days, around hundred million of sharks are still hunted each year(Heltus, 2013), to be served on luxury tables surrounded by those believers in things that they do not even prove whether the belief is reliable. Therefore, in the generation that people are mostly educated, sharks should no longer have to be continuously killed for their fins.
The navy adopted the technology for use by submarines to detect objects in the water.
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.
First, according to the reading passage the sounds were detected were produced by the okra whales during a courtship ritual and those sounds were captured by the submarines. The professor refutes this point and says that the okra whales always occupy the surface waters, whereas the Sub Marines located deep in the water, and it's merely impossible for the submarines to capture those sounds.
In conclusion, radar is something that is used all around us even though it is normally invisible. When people use radar, they are usually trying to accomplish one of three things; detecting the presence of an object at a distance, detect the speed of an object, or to map something. All three of these activities can be accomplished simply by using echo and Doppler shift. These two concepts are easy to understand because your ear hears echo and Doppler shift every day. Radar makes use of the same techniques using radio waves.
These radar systems differ from other mechanical radars in the sense that they are in a fixed position where other mechanical radars are need to be aimed and
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.
Alnut Kelber, Anna Balkenius, and Eric. J. Warrant studied the night-time vision of a nocturnal hawkmoth, Deilephila elpenor. They wanted to know if the hawkmoths can truly see colors at night, or if they are using other means to find the right kind of flowers to feed from. For example, humans cannot see colors at night and therefore have a harder time differentiating between objects using vision alone. However, a person could find food in a dark room using his or her other senses, such as smell or taste, or could rely on colorless vision to choose food based on its shape. The scientists tested a series of experiments to show that hawkmoths use color-vision at night, as opposed to reverting to their other senses like humans do.
“One would think that so important a contribution to the world’s technology would be chronicled with great care at every step…This, unfortunately, is not the case, and for reasons quite understandable” (Page 14). Sometimes history can be hard to distinguish from truth and legend, the history of radar is no exception. 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 information about radar to come up with their own variations for different applications. As a result, the true origin of radar has become blurred within conflicting claims.
Acoustics is a science that deals with the study of sound. It is known to be one of the branches of physics; studying oscillations and sound waves from the lowest to high frequencies. Acoustics is known to be one of the oldest sciences, and dates back to ancient times as people had the need to understand the nature of speech and hearing. The main reason acoustics was discovered and is one of the oldest sciences is because of the need for the knowledge of the sounds of music and musical instruments. Pythagoras, an ancient mathematician, was the first person to ever find out that tone height corresponds to the length of the sting or tube. While Aristotle, Pythagoras apprentice at the time, helped more to explain that an echo is created as the sound reflection from obstacles.
An acoustic wave can simply be described as a longitudinal wave. A longitudinal wave is a wave that vibrates and moves in the direction of its propagation. This means the medium is either in the same or opposite direction of the way the wave travels. Acoustic waves are a form of Mechanical longitudinal waves; these waves are otherwise known as compression waves or compressional waves. Compressional waves obviously produce compression, decompression, and rarefaction to travel.