In telecommunication, a propagation path obstruction is a man-made or natural physical feature that lies near enough to a radio path to cause a measurable effect on path loss, exclusive of reflection effects. An obstruction may lie to the side, above, or below the path. Ridges, bridges, cliffs, buildings, and trees are examples of obstructions. If the clearance from the nearest anticipated path position, over the expected range of Earth radius k-factor, exceeds 0.6 of the first Fresnel zone radius, the feature is not normally considered an obstruction.
Famous quotes containing the words path and/or obstruction:
“Examples are cited by soldiers, of men who have seen the cannon pointed, and the fire given to it, and who have stepped aside from he path of the ball. The terrors of the storm are chiefly confined to the parlour and the cabin.”
—Ralph Waldo Emerson (1803–1882)
“Every obstruction of the course of justice,—is a door opened to betray society, and bereave us of those blessings which it has in view.... It is a strange way of doing honour to God, to screen actions which are a disgrace to humanity.”
—Laurence Sterne (1713–1768)