Sonar, or Sound Navigation and Ranging, is a remote sensing technology that utilizes the principles of acoustic physics to detect and measure the location of objects underwater or within other dense media. The system operates by emitting short, controlled pulses of sound into the medium and then accurately timing the returning echoes. By measuring the time difference between the initial pulse and the reception of the echo, and knowing the speed of sound in the medium, the distance to the reflecting object can be calculated. This method allows for various applications, including mapping the contours of the seafloor (bathymetry), monitoring underwater currents, and detecting the presence and depth of submerged materials, making it an essential tool in oceanographic science and navigation.