When the signal stopped the land based stations would transmit the bearing from their station to the ship. This system in reverse is still used to day. Marine radio are sold with a direction finding antenna. This permits the seafarer to triangulate his position to a few land based radio stations. This system has one master station and two or more secondary stations.
All stations sequentially transmit a group of pulses.
Loran uses ground waves. These low frequency signals in the 100KHz range, provide the long range of 1000 to 1500 miles, enjoyed by this system. The low frequency signals are effected by the Ionosphere. Night time and solar storms reduce the accuracy of this navigation aid. At a 100 miles from its master station has an accuracy of 30 yds by day and 100 yds at night.