Three dimensional tomography of the ionosphere using a radio telescope Interferometer

Space weather is now widely appreciated as having a critical influence on modern society, which relies heavily on communication and navigational systems that are strongly affected by the ionosphere. Precise GPS positioning and satellite communication can be disrupted if there are irregularities in the ionosphere. It is therefore becoming increasingly important to understand in detail the characteristics and behavior of the ionosphere on small spatial (<1km) and temporal (<1 min) scales. We present initial studies of a technique to resolve such structures using a radio telescope interferometer, the Very Large Array (VLA). Such interferometers are extremely sensitive to relative density changes, or total electron content (TEC), in the ionosphere. The reconstruction technique makes use of regularization functions, which incorporate the VLA TEC data as well as similar data from GPS receivers.