Friday, June 14, 2019
Calculated Versus Observed Underwater Sound Speed Essay
Calculated Versus Observed Underwater Sound Speed - audition ExampleThe speed of depart in air is approximately figured out by the formula . . . speed of sound (m/s) = 331.5 + 0.60 T(C). The speed or velocity, at which sound travels through water was first researched by Sir Isaac Newton in 1687 when he found that measurements of sound in fluids relied only on the physical properties of the fluid, such(prenominal) as elasticity and density (Funk & Wagnalls). The speed of sound in water is about four times majusculeer than that in air. Although this seems to contradict the physical police force that the denser the gas, the slower the speed of sound, the sound speed is actually determined more(prenominal) by the elasticity of the medium (Urick, 1983).In 1822, Daniel Colloden used an underwater bell in an attempt to calculate the speed of sound underwater in Lake Geneva, Switzerland. His attempts resulted in figures remarkably close to todays accepted values ( acoustics . . . 2006) . But sound speed cannot be discussed without mention of Jaque Sturm, French mathematician, who made the first accurate measurements of sound velocity in water in 1826. World War I created a great necessity to study the propagation of sound under water, with more progress in World War II and increased understanding from current research (Funk & Wagnalls). ... His attempts resulted in figures remarkably close to todays accepted values (Acoustics . . . 2006). But sound speed cannot be discussed without mention of Jaque Sturm, French mathematician, who made the first accurate measurements of sound velocity in water in 1826. World War I created a great necessity to study the propagation of sound under water, with more progress in World War II and increased understanding from current research (Funk & Wagnalls). The fact that sound moves in a straight specify in a medium of equal density (ibid.) led to studies of water variables. Sonars accuracy depends upon1. The reflection of sounds pr opagated in water. 2. Whether sound is reflecting or refracting. 3. Levels of salinity, while generally everlasting in the open maritime, greatly changes how sound travels through shallow water. 4. Temperature, a foremost factor in sound speed calculations, usually becomes lower at greater depths of water, decreasing sound speed at about 3 m/sec per degree Celsius. Below 1000m, though, temperature becomes generally constant and pressure is the dominant consideration. But a depth change of about 165m can cause the same change in sound speed as a one-degree temperature drop. Acoustic Tomography (a type of underwater CT scan) and Sofar Floats are examples of technologies and instruments that measure the movement of large scale ocean water mass. A unique feature of the ocean is the Sofar Channel in the upper regions of the deep ocean. In this layer of the ocean, at about 1250 meters below the surface in the northwest Atlantic, the temperature and pressure act to come through a long range acoustic path or channel(Acoustic . . . 2006). The SOFAR float is an instrument designed to be neutrally buoyant at a certain(p) depth and
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