Ionospheric demodulation of powerful pulsed radio waves: A potential new diagnostic for radars suggested by Troms⊘ heater results

摘要

Pulses of radio waves in the ELF and VLF range can be generated in the auroral ionosphere by the transient conductivity perturbation (in the presence of an ambient electric field) caused by artificial heating using pulsed high-power HF radio waves. Examples of such waves generated by the Max-Planck heating facility near Troms⊘ are briefly reviewed. The waves generated can be used to provide information on the horizontal ionospheric electric field. A model which has successfully explained these results quantitatively is used to predict the amplitudes produced by lower power HF radars (partial reflection experiments) in auroral regions. The model results show ELF/VLF amplitudes which are typically an order of magnitude below those obtained for the Troms⊘ heater but may nevertheless provide useful ionospheric information as a byproduct of the radar's normal operation.