Simulating a VLF Radio Network for Spatial Estimates of D-region Enhancement from Energetic Precipitation Events
Abstract
VLF radio waves propagate in a natural waveguide formed between Earth's surface and the D-region of the ionosphere. High power VLF transmitters support global communication and navigation systems, but these signals can also be used to remotely sense the lower ionosphere. Energetic particle precipitation disturbs the D-region and perturbs the amplitude and phase of VLF signals propagating below. To produce spatial estimates of the electron density enhancements associated with precipitation events, we demonstrate a theoretical network of several VLF transmitters and receivers with crisscrossing propagation paths. Each individual receiver provides information about the integrated ionosphere along the great circle path from a transmitter, but underlying spatial correlations and intersections with paths from other transmitters and receivers constrains the estimated ionosphere. An empirical model for quiet behavior provides an initial guess of the D-region as a function of latitude and solar zenith angle. We utilize an ensemble Kalman filter technique to assimilate real signal phase measurements from the network receivers with synthetic measurements generated by the Long Wavelength Propagation Capability through the initial estimated ionosphere. By comparing the real and model measurements over several iterations, the filter converges to a spatial estimate of the disturbed ionosphere. This simulation suggests how a network of real VLF receivers could provide indirect observations of a precipitation patch.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMSM43D3614G
- Keywords:
-
- 2716 Energetic particles: precipitating;
- MAGNETOSPHERIC PHYSICSDE: 2720 Energetic particles: trapped;
- MAGNETOSPHERIC PHYSICSDE: 2774 Radiation belts;
- MAGNETOSPHERIC PHYSICSDE: 7867 Wave/particle interactions;
- SPACE PLASMA PHYSICS