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:
“Culture is the suggestion, from certain best thoughts, that a man has a range of affinities through which he can modulate the violence of any master-tones that have a droning preponderance in his scale, and succor him against himself. Culture redresses this imbalance, puts him among equals and superiors, revives the delicious sense of sympathy, and warns him of the dangers of solitude and repulsion.”
—Ralph Waldo Emerson (1803–1882)
“No doubt, the short distance to which you can see in the woods, and the general twilight, would at length react on the inhabitants, and make them savages. The lakes also reveal the mountains, and give ample scope and range to our thought.”
—Henry David Thoreau (1817–1862)
“In the range of things toddlers have to learn and endlessly review—why you can’t put bottles with certain labels in your mouth, why you have to sit on the potty, why you can’t take whatever you want in the store, why you don’t hit your friends—by the time we got to why you can’t drop your peas, well, I was dropping a few myself.”
—Mary Kay Blakely (20th century)