Passage of short radio waves through the low ionosphere N. D. Naumov 12-th Central Research Institute, Sergiev Posad-7, Moscow region, 141300, Russia E-mail: beloros@mail.ru A technique to calculate the amplitude of short radio waves passing through low ionosphere has been developed on the basis of the nonlinear geometrical optics. <...> На основе нелинейной геометрической оптики сформулирован метод оценки амплитуды коротких радиоволн при прохождении через нижнюю ионосферу! <...>