Ground-Based Measurements of the Outer-Ionosphere Turbulence Induced by a High-Power VLF Transmitter

We present experimental results on the detection of artificial irregularities produced in the ionospheric plasma by a high-power VLF transmitter. The analysis of TEC variations and ionosonde data was used for the diagnostics of ionospheric turbulence. Spatial distribution of the electric field amplitude of the VLF transmitter was calculated for selection of the NAVSTAR and GPS satellites the signal from which passes through the perturbed region. A quite different TEC variation curve was observed in the reference measurement when the transmitter was out of operation. Operation of the VLF transmitter resulted in the appearance of F spread in the ionosonde data (the effect took place at night). The experiment showed for the first time that with the help of ground-based measurements of TEC it is possible to study the region of turbulence in the outer ionosphere induced by the operation of a VLF radio station.