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In radar or sonar applications, linear chirps are the most typically used signals to achieve pulse compression. The pulse being of finite length, the amplitude is a rectangle function . If the transmitted signal has a duration T {\displaystyle T} , begins at t = 0 {\displaystyle t=0} and linearly sweeps the frequency band Δ f {\displaystyle ...
Sonar systems are generally used underwater for range finding and detection. Active sonar emits an acoustic signal, or pulse of sound, into the water. The sound bounces off the target object and returns an echo to the sonar transducer. Unlike active sonar, passive sonar does not emit its own signal, which is an advantage for military vessels.
Synthetic-aperture sonar (SAS) is a form of sonar in which sophisticated post-processing of sonar data is used in ways closely analogous to synthetic-aperture radar. Synthetic-aperture sonars combine a number of acoustic pings to form an image with much higher along-track resolution than conventional sonars.
Word walls can be used in classrooms ranging from pre-school through high school.Word walls are becoming commonplace in classrooms for all subject areas. High schools teachers use word walls in their respective content areas to teach spelling, vocabulary words, and mathematics symbols.
Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. [4] Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, [5] and sodar (an upward-looking in-air sonar
AN/AQS-13 dipping sonar deployed from an SH-3 Sea King. The AN/AQS-13 series was a helicopter dipping sonar system for the United States Navy.These systems were deployed as the primary inner zone anti-submarine warfare (ASW) sensor on aircraft carrier based helicopters for over five decades. [1]
Side-scan uses a sonar device that emits conical or fan-shaped pulses down toward the seafloor across a wide angle perpendicular to the path of the sensor through the water, which may be towed from a surface vessel or submarine (called a “towfish”), or mounted on the ship's hull.
Echo sounding or depth sounding is the use of sonar for ranging, normally to determine the depth of water . It involves transmitting acoustic waves into water and recording the time interval between emission and return of a pulse; the resulting time of flight , along with knowledge of the speed of sound in water, allows determining the distance ...