Radio

thumb|An antenna farm hosting various [[radio antennas on Sandia Peak near Albuquerque, New Mexico, United States]]

radio broadcasting using radiowaves with wavelengths between 10 to 100 meters, and frequencies between 3 to 30 megahertz

facility, site or item with transmitter and/or receiver used for radiocommunication

Narrowband signals are signals that occupy a narrow range of frequencies or that have a small fractional bandwidth. In the audio spectrum, narrowband sounds are sounds that occupy a narrow range of frequencies. In telephony, narrowband is usually considered to cover frequencies 300–3400 Hz, i.e. the voiceband.

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remote sensing technique

geographic area which which a radio station can communicate

the absolute time instant when a signal reaches a receiver