Position Determination of Radiation Sources using Curvature of the Electromagnetic Wave´s Front

There is an actual problem of finding new or improvement of the position determination methods (PDM) of the RS in the radio engineering systems (RES). There are many PDM methods in RES. But it is also submitted in the work about possibility of the location determination (bearing and range) using curvature of the electromagnetic wave front without showing mathematical formulas for its calculation. So the main object of this report to view PDM features with mathematical formulas for bearing and range of the RS derivation and its calculation error estimation by using curvature of the electromagnetic wave front.