Yu.K. Kalinin

As much as maximum usual frequency (MUF) is one of the major characteristics of ionosphere radio traces. Excess by working frequency of radio means of size MUF can lead to losses of signal strength till 40-50 dB that in most cases will make impossible means work. At the same time it is known that now there is a deficiency of working channels suitable for work of radio engineering means. Therefore increase of MUF by influence of an oblique powerful radio-wave is a perspective way of maintenance of radio engineering systems additional frequency channels. In work it is informed on historically first precedent of increase MUF on 7 % of radio traces in ionosphere by extent of 2000 km., when for oblique influence broadcasting means, and for control - station of vertical sounding of an ionosphere in the middle of a trace were used. Since 1972, for oblique influence on an ionosphere the powerful radio-wave used unique means - powerful radar with electronic reorganization on frequency and on angle of radiation of antenna system. By means of consecutive increase in frequency it was possible to create at night an artificial ionosphere with MUF in 2-3 times, exceeding its undisturbed condition. In one of such sessions it was possible to carry out over horizon detection of start of a ballistic missile in the conditions of total absence of active noises