What's the difference between sonar and radar?

Sonar, an acronym for Sound Navigation and Ranging, is a detection system based on the reflection of underwater sound waves, just as radar is based on the reflection of radio waves in air. The sonar emits ultrasonic pulses using a submerged radiating device. It listens with a sensitive microphone, or hydrophone, for reflected pulses from potential obstacles or submarines. The sonar is used by airplanes and ships each deploying a different type of sonar. Airplanes use a device called a sonobuoy, consisting of a hydrophone mounted on a floating buoy. Spin-offs from the development of sonar technology include acoustic oceanography, the study of ocean properties using a variety of acoustic means, and an imaging or remote-sensing technique using computer analysis to study the data collected when acoustic signals are passed through an object. Radar is an electronic system, used to locate objects beyond the range of vision, and to determine their distance by projecting radio waves against ...  more

Sonar, an acronym for Sound Navigation and Ranging, is a detection system based on the reflection of underwater sound waves, just as radar is based on the reflection of radio waves in air. The sonar emits ultrasonic pulses using a submerged radiating device. It listens with a sensitive microphone, or hydrophone, for reflected pulses from potential obstacles or submarines. The sonar is used by airplanes and ships each deploying a different type of sonar. Airplanes use a device called a sonobuoy, consisting of a hydrophone mounted on a floating buoy. Spin-offs from the development of sonar technology include acoustic oceanography, the study of ocean properties using a variety of acoustic means, and an imaging or remote-sensing technique using computer analysis to study the data collected when acoustic signals are passed through an object.  more