A navigation method and system suitable for highly accurate all-weather navigation of vehicles such as ships and aircraft. An initial position of the vehicle relative to a plurality of known points each located at predetermined geographic positions is first determined. The distance or range of the initial position from each of the plurality of known points is determined and when the vehicle moves to a second and unknown position, the difference between the propagation time of electromagnetic wave energy transmitted from each of the plurality of known points at the initial and second positions is determined to thereby determine an incremental change in the distance to the second position from each of the plurality of known points. The distance of the initial position and the incremental change in distance from each of the plurality of points are algebraically summed to thereby determine the distance of the second position from each of the plurality of known points, and the second position is determined from the determined distances of the second position from each of the plurality of known points. The invention is compatible with existing navigation systems such as LORAN or other systems which periodically transmit wave energy at regular intervals.