Ultrasound close ultrasoundSound with a frequency greater than 20,000 Hz (20 kHz). is sound with a frequency greater than 20,000 Hz. Humans cannot hear ultrasound but many other animals can, such ...
It works in the same way as sonar but with radio waves in place of ultrasound. A short pulse of radio waves is transmitted and the time it takes for the reflection (the echo) to return is measured.
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