Optimal field of ionosphere radio-probing for underground nuclear explosions identification

For option of ionosphere radio probing optimal conditions at remote monitoring of underground nuclear explosions it is necessary the attainments of ionosphere disturbances spatial sizes induced by explosions. In the paper experimental data obtained during 13 underground nuclear explosions conducted on the Semipalatinsk test site for 1987-1989 have been analyzed. Doppler radio probing of ionosphere has been carried out at 29 inclined radio directions. The largest length of radio direction was equal to 1320 km (Novosibirsk- Almaty). To interpret of the experimental results the coordinates and waves height reflection the point have been calculated. In the experiments the ionosphere disturbances have been observed at the latitudes from 97 to 290 km. Maximal registered size of ionosphere disturbance field in the described experiments made up: toward the south 99 km, toward the north 39 km, toward the west 73 km