What's That Helicopter Doing Above Arlington, Middlesex County, Massachusetts? A federal agency will conduct low-altitude flights over the area in advance of the Boston Marathon, April 12-15

ARLINGTON, MA - Don't be alarmed if you hear helicopters buzzing Arlington over the next few days; it's the U.S. Department of Energy measuring radiation levels.

From April 12-15, the department's National Nuclear Security Administration is gathering baseline radiation level data ahead of the Boston Marathon next weekend, the Massachusetts Emergency Management Agency said.

The NNSA notes these measurements are a normal part of security and emergency preparedness, meant simply to measure naturally occurring background radiation to establish baseline levels.

The low-level flights will cover about 13 square miles. Helicopters equipped with radiation sensing technology will fly out of Joint Base Andrews, marking a grid pattern over the area at about 150 feet (or higher) above the ground and moving around 80 miles per hour.

Flyovers will occur only during daylight hours and are estimated to take about two days to complete, the NNSA said in a press release. The administration wants to ensure the public is aware of these upcoming flights so people aren't alarmed when they see the low-flying helicopters.

Original article can be found here: http://patch.com