People in San Francisco, Berkeley and Pacifica may hear a stir in the air this week as a helicopter measuring radiation is scheduled to fly over the cities this week.

With this "Aerial Radiological Survey," the helicopter is helping the Department of Homeland Security, Department of Energy and Lawrence Berkeley National Lab to conduct research to help the federal government better detect nuclear and radiological material.

According to a memo sent to Berkeley's mayor and city council, the aircraft was scheduled to fly in San Francisco on Tuesday, Thursday and Friday, Berkeley on Wednesday and Pacifica on Thursday.

Berkeleyside noted that similar tests were conducted in August 2012.

Some Bay Area residents were complaining on Twitter that the choppers were flying too low. "It's so low it's "mowing the lawn," one redident told Berkeleyside.