File this under things you might not know about presidential inaugurations.
Helicopters will be flying low over downtown D.C. and other areas in the region to assess radiation ahead of the Jan. 20 inauguration. The U.S. Department of Energy’s National Nuclear Security Administration began the flights on Monday.
The agency's nuclear emergency support team aircraft will measure naturally occurring background radiation as part of standard preparations to protect public health and safety on the day of the event, according to a news release.
You may see a twin-engine Bell 412 helicopter, which is equipped with passive radiation sensing technology, flying in a grid pattern as low to the ground as 150 feet at approximately 80 mph.
Flyovers will occur only during daylight hours and are estimated to take approximately two hours to complete per area.
"The aircraft measurements will be purely scientific in nature, and no surveillance or other form of monitoring will occur during these flights," the agency said.