Whitepaper #219 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: solar physics; user-need-driven basic space weather research.
We describe the steps necessary to realize Faraday rotation tomographic scanning of the corona. Spacecraft could be used to quickly generate low resolution tomographic scans suitable for studying coronal mass ejections, critical to developing early warning space weather forecasting systems, and natural radio sources would be suitable for studying slowly-evolving coronal structures like streamers.