Joshua Semeter

Research Interests: Ionospheric and space-plasma physics; radar signal processing; spectroscopy of atmospheric airglow and aurora; optical sensors; image reconstruction and tomography

Website: http://people.bu.edu/jls

Dr. Semeter’s research concerns interactions between the Earth’s ionized outer atmosphere (the ionosphere) and the space environment.   One manifestation is the aurora-borealis, produced by the release of electromagnetic energy stored in the distant magnetosphere.   The ionosphere is electrically conducting, and so it absorbs, refracts, and modulates radio waves.  Understanding these effects is essential for the design and operation of global navigation (GPS) and communication systems.  Electric currents flowing in the ionosphere also affects terrestrial technologies, such as power grids and pipelines, via induction.  Ionospheres are inherent to all stellar-planetary systems, and their connection with the absorption of ionizing radiation suggests a fundamental connection with the evolution of habitable environments in the universe.

Activities in Dr. Semeter’s lab include the development of optical and magnetic sensor technologies, radar experiment design and signal processing (with focus on incoherent scatter radar), and the application of tomographic and other inversion techniques to the analysis of distributed, multi-mode measurements of the space environment.