NRL researchers monitor changing Arctic using sound

U.S. Naval Research Laboratory scientists developed Ice-tethered Acoustic Buoys to monitor the acoustic and oceanographic environment in the changing Arctic. The buoys provide critical oceanographic data to improve prediction ...

Using noise to enhance optical sensing

In conventional sensing methods, noise is always a problem, especially in systems that are meant to detect changes in their environment that are hardly bigger or even smaller than the noise in the system. Encountering this ...

page 1 from 23


Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency. The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency. For example, if a newborn baby's heart beats at a frequency of 120 times a minute, its period (the interval between beats) is half a second.

This text uses material from Wikipedia, licensed under CC BY-SA