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The term echolocation was coined by 1944 by the American zoologist Donald Griffin, who, with Robert Galambos, first demonstrated the phenomenon in bats. [1] [2] As Griffin described in his book, [3] the 18th century Italian scientist Lazzaro Spallanzani had, by means of a series of elaborate experiments, concluded that when bats fly at night, they rely on some sense besides vision, but he did ...
Swedish soldiers operating an acoustic locator in 1940. Acoustic location is a method of determining the position of an object or sound source by using sound waves. Location can take place in gases (such as the atmosphere), liquids (such as water), and in solids (such as in the earth).
[3] "Sonar" can refer to one of two types of technology: passive sonar means listening for the sound made by vessels; active sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. [4]
Some species of hawkmoths (Sphingidae) produce ultrasound capable of sonar jamming. [25] Sonar jamming capability has evolved independently in at least six subfamilies. [26] Because sonar jamming seems to require high duty cycle ultrasound, it is believed to be a derived form of the simpler ultrasound used for aposematism and mimicry. [27]
By measuring the difference in time between the pulse being transmitted and the echo being received, it is possible to determine the distance. The measured travel time of Sonar pulses in water is strongly dependent on the temperature and the salinity of the water. Ultrasonic ranging is also applied for measurement in air and for short distances.
3.2.2 Echolocation. 3.2.3 Electroreception. ... is the smallest detectable difference between two stimuli, ... (like sonar). They most often use this to navigate ...
Human echolocation, the use of sound by people to navigate. Sonar (sound navigation and ranging), the use of sound on water or underwater, to navigate or to locate other watercraft, usually by submarines. Echo sounding, listening to the echo of sound pulses to measure the distance to the bottom of the sea, a special case of Sonar.
The interactions between marine mammals and sonar have been a subject of debate since the invention of the technology. Active sonar , the transmission equipment used on some ships to assist with submarine detection, is detrimental to the health and livelihood of some marine animals . [ 1 ]