A single transmitter can be used to give a line of position (LOP) of the craft. The (true) bearing to the station from the plane, TB or QUJ, is composed of the planes true heading, TH, plus the relative bearing, RB, of the station. The bearing of the plane from the station (QTE) is found by adding 180° to the QUJ figure.
The line of position is then the line of bearing QUJ (i.e. from the station to the plane) passing through the station.
For the diagram on the right, we have:
A radio fix on two stations can be found in exactly the same way. The intersection of the two position lines gives the position of the plane. For the diagram on the right, the LOPs are found as before:
Remembering that the LOPs pass through their respective stations, it is now simple to find the location of the aircraft.