The Doppler Effect can be used to measure the velocity of an object by comparing the wavelength of the sound sent out to the wavelength of the sound reflected by in the echo. A sonar device is usually used to calculate the velocity of the object. Doppler Radar works on a similar principle to measure the speed of storms in weather prediction. Bats can find moths Bats use echoes to find good tasting moths, while flying around at night. The bat sends a sharp click or chirping sound and then hears and processes any echoes off other objects in the area.
Bats have large ears that are very sensitive to sounds in certain wavelengths.
It continues to send out sound and receive echoes until it zeroes in on the moth and has a good meal. Sonar Sonar devices often can process echoes to determine the size and shape of objects under water. Sonar is not as effective in air, and radar is usually used in that situation. When sound reflects off a stepped grating, the echo can have interesting effects. Ancient people used these effects Echoes from the great Mayan pyramid at Chichen Itza, Mexico sound like the quetzal bird that is found in the Mayan area.