Just managed to get this guy as we were going by. Easily one of the coolest things I've seen at EIA. The Boeing OC-135B (basically a 707) is part of the Treaty of Open Skies. The member countries of this treaty are allowed to conduct aerial serveillance of the other members. The aircraft and sensors have to meet specific regulations. This is the airplane that the United States uses. Them yanks are spying on us.
Canada uses a CC-130 Hercules for our serveillance.