Ionosphere ray radiotomography with inclusion of refraction

Using the example of the ionosphere radiotomography, a nonlinear statement of the ray tomography problem with inclusion of sounding ray refraction is considered. It is shown that, in the case of weak refraction, the nonlinear tomography problem can be solved as a sequence of linear problems whose solution process is realized by an iterative procedure with every approximation of the refractive index calculated using the ray trajectory obtained in the preceding approximation.