A helicopter flew over Berkeley and the surrounding Bay Area at low altitude Wednesday as part of a federal research project to measure natural background radiation.

The twin-engine Bell 412 helicopter, which belongs to the U.S. Department of Energy’s National Nuclear Security Administration, was scheduled to fly over the region — at approximately 80 miles per hour at an altitude of about 300 feet or higher — from Tuesday through to Sunday, according to a press release from the National Nuclear Security Administration.

Equipped with gamma radiation sensing technology, the helicopter will gather data that will help improve aerial radiation measurement capabilities that local, state and federal entities use, the release said.

The flyovers contribute to a research project by the U.S. Department of Homeland Security’s Domestic Nuclear Detection Office.