(lôr'ăn´´), long-range, accurate radio navigational system used by a ship or aircraft to confirm or to determine its geographical position. The term loran is derived from the words long-range navigaton. Loran, operating in the 1,700-kHz range, measures the time-of-arrival difference between two signals transmitted from two geographically separated ground stations. The pulse from the first station, called the master, triggers the second station, called the slave, into transmitting a similar pulse after a set time delay. Knowing the elapsed time difference, the navigator refers to a loran chart and selects his line of position. The chart contains groups of hyperbolic curves of constant time differences between particular station pairs. The position of the receiver (ship or airplane) will be somewhere along the curve that corresponds to the measured time difference. By taking a similar time-difference reading from a second pair of stations whose curves intersect those of the first pair, a definite geographic fix may be obtained.
pronunciation (1932) : a system of long-range navigation in which pulsed signals sent out by two pairs of radio stations are used to determine the l
Long-Range Aid to Navigation. A former electronic system which determined hyperbolic lines of position by measuring the difference in time of recept
/lawrən/ noun a system of navigation in which the intervals between reception of pulsed signals sent out by widely spaced radio stations...