Range
The useful direct range of a two-way radio system depends on radio propagation conditions, which are a function of frequency, antenna height and characteristics, atmospheric noise, reflection and refraction within the atmosphere, transmitter power and receiver sensitivity, and required signal-to-noise ratio for the chosen modulation method. An engineered two-way radio system will calculate the coverage of any given base station with an estimate of the reliability of the communication at that range. Two-way systems operating in the VHF and UHF bands, where many land mobile systems operate, rely on line-of-sight propagation for the reliable coverage area. The "shadowing" effect of tall buildings may block reception in areas within the line-of-sight range which can be achieved in open countryside free of obstructions. The approximate line-of-sight distance to the radio horizon can be estimated from : horizon in kilometers = 3.569 times the square root of the antenna height in meters.
There are other factors that affect the range of a two-way radio such as weather, exact frequency used, and obstructions.
Read more about this topic: Two-way Radio
Famous quotes containing the word range:
“Jane Addams, founder of Hull House, once asked, “How shall we respond to the dreams of youth?” It is a dazzling and elegant question, a question that demands an answer—a range of answers, really, spiraling outward in widening circles.”
—William Ayers, U.S. author. To Teach: The Journey of a Teacher, ch. 7 (1993)
“but we wish the river had another shore,
some further range of delectable mountains,”
—Robert Lowell (1917–1977)
“The more the specific feelings of being under obligation range themselves under a supreme principle of human dependence the clearer and more fertile will be the realization of the concept, indispensable to all true culture, of service; from the service of God down to the simple social relationship as between employer and employee.”
—Johan Huizinga (1872–1945)