Line-of-sight Propagation As A Prerequisite For Radio Distance Measurements
Travel time of radio waves between transmitters and receivers can be measured disregarding the type of propagation. But, generally, travel time only then represents the distance between transmitter and receiver, when line of sight propagation is the basis for the measurement. This applies as well to RADAR, to Real Time Locating and to LIDAR.
This rules: Travel time measurements for determining the distance between pairs of transmitters and receivers generally require line of sight propagation for proper results. Whereas the desire to have just any type of propagation to enable communication may suffice, this does never coincide with the requirement to have strictly line of sight at least temporarily as the means to obtain properly measured distances. However, the travel time measurement may be always biased by multi-path propagation including line of sight propagation as well as non line of sight propagation in any random share. A qualified system for measuring the distance between transmitters and receivers must take this phenomenon into account. Thus filtering signals traveling along various paths makes the approach either operationally sound or just tediously irritating.
Read more about this topic: Line-of-sight Propagation
Famous quotes containing the words prerequisite, radio and/or distance:
“You have to penetrate a woman’s defenses. Getting into her head is a prerequisite to getting into her body.”
—Bob Guccione (b. 1930)
“We spend all day broadcasting on the radio and TV telling people back home what’s happening here. And we learn what’s happening here by spending all day monitoring the radio and TV broadcasts from back home.”
—P.J. (Patrick Jake)
“Like the water, the Walden ice, seen near at hand, has a green tint, but at a distance is beautifully blue, and you can easily tell it from the white ice of the river, or the merely greenish ice of some ponds, a quarter of a mile off.”
—Henry David Thoreau (1817–1862)