Low-altitude radiation survey flights over downtown Boston and the Boston Marathon race route will take place from Friday, October 8, through Monday, October 11, by a team from the National Nuclear Security Administration.

The surveys to be done using the NNSA’s Aerial Measuring System (AMS) are what the agency calls “a normal part of security and emergency preparedness activities.”

More information and video footage of the NNSA’s aerial assessments are available online.