An Analysis of Some Anomalous Properties of Equiphase Contours

If one thinks of the voltage of a radio signal as a function of the location of some target point, then the phase of this voltage is also such a function. One might imagine that since the voltage exhibits no peculiar properties, neither does the phase; but this is not true. There are many cases for which the phase becomes a multivalued function. This fact is very important in the theory of the phase measurement type of radio surveying or navigational systems; for the phase difference between two points depends not only on the location of the points, but also on the path over which the target is carried.