“If you observe these signals, they vary dramatically with time. Most radio waves have limited range, but VLF signals interact with and bounce off the Earth’s ionosphere, allowing the signals to be received thousands of kilometers away. Marshall has found an answer in very low frequency (VLF) radio waves, used by the Navy to communicate with ships and submerged submarines. You could do it with multiple satellites to cover a larger area, but that gets very expensive,” Marshall said. It doesn’t tell you what’s happening elsewhere, or give an idea of the spatial extent of the coupling region. “You can measure the particles with a satellite, but it’s a single point measurement. Marshall wants to build a three-dimensional map of the particles across thousands of square kilometers. Whether from a ground station looking up or a satellite staring down, they can only see what is directly in their path. The process that leads them to enter Earth’s atmosphere has long been recognized, but past studies have generally monitored single locations. These particles can be damaging to spacecraft electronics and the health of astronauts. We want to better understand that coupling.”
![submarine vlf receiver submarine vlf receiver](http://acronymsandslang.com/acronym_image/1998/ac339b174984bc368ad86faffb50b403.jpg)
“But some of them get dumped into Earth’s atmosphere. “We’re interested in high-energy electron particles in Earth’s radiation belts,” Marshall said. Smead Department of Aerospace Engineering Sciences at the University of Colorado Boulder has earned a prestigious 2021 CAREER Award from the National Science Foundation for the project. The assistant professor in the Ann and H.J. Navy to communicate with submarines under the ocean. Map of Canada showing prospective radio receiver sites.īob Marshall is studying the interaction of high-energy particles in orbit around Earth using an unlikely data source: radio signals sent by the U.S.