Importance of Sound Speed

Sound moves in a straight line in a medium of equal density (Funk &amp. Wagnall, 1979), but sonar depends on the reflection of sounds that are conducted underwater. Whether the sound is reflecting (throwing sound back from a surface) or refracting (bending the normally straight path of sound toward a new direction) is of great importance to sonar applications. Levels of stratification and levels of salinity greatly change how sound travels through shallow water. Accurate calculations and research will give sonar operations more accurate and reliable results.
The speed and velocity at which sound travels through the water were first researched by Sir Isaac Newton in 1687. He began these investigations when he discovered that measurements of sound as it travels through fluids relied only on the physical properties of the fluid, such as its elasticity and density. The first accurate measurements of the speed of sound in water were made in 1826 by the French mathematician Jacque Sturm. Further studies of how sound originated and was carried underwater became crucial from a military standpoint in World War I with the introduction of the submarine. Great progress was made in our understanding of sonar during World War II and the issue has received increasing attention in more modern times (Funk &amp. Wagnalls, 1979).
The speed of sound in water depends on different factors including temperature, salinity and wave depth (Derencin, 2002). There is a positive relationship between water temperature and depth – as the depth increases, the water temperature decreases. The term ‘isothermal’ is used to describe a uniform water temperature (Standards and Curriculum Division, 1944).&nbsp.