Today, Japan’s National Institute of Information and Communications Technology (NICT) announced the commencement of operations of a VHF radar that will study how plasma bubbles cause radio interference that can affect navigation systems.
The VHF radar, located at the King Mongkut’s Institute of Technology Ladkrabang (KMITL) campus in Chumphon, Thailand, is a collaboration between NICT and KMITL. The site at Chumphon was chosen because of its proximity to the magnetic equator, where plasma bubbles are expected to be generated.
Using the radar, scientists hope to learn more about how plasma bubbles, which occur in the ionosphere and travel along the Earth’s magnetic lines after sundown, cause radio propagation disturbances. Such radio propagation disturbances have been known to degrade satellite-based navigation and communications, affecting GNSS systems around the equator and also at middle latitudes.
According to NICT, “The radar system at Chumphon consists of 18 antennas installed in the east-west direction, using radio waves in the VHF band (39.65 MHz). The radio waves transmitted from the radar are reflected by the plasma irregularity caused by plasma bubbles in the ionosphere. By observing the reflected radio waves, the location and velocity of the plasma bubbles can be monitored.”