Manifestation of oblique radio heating in data of the vertical sounding of the ionosphere

It is shown that a method involving the extraction of ionograms at the midpoint of the path of high-power radio-wave propagation can be used to detect the presence of traveling ionospheric disturbances. During radio-heating periods the traces of the disturbances move upward, while in the absence of this effect the traces move in the opposite direction. Such effects are observed in daytime in the F1-region.