A Good Year for Blimps

Raytheon

Later this year, apparently, two blimps will rise and hover in the air above Baltimore. They will be equipped with radar that can detect aircraft in an area of about 363,000 miles around and ground traffic in an area of about 62,000 miles around. Here's how they work: http://apps.washingtonpost.com/g/page/national/surveillance-aircraft-floating-high-above-maryland/752/?Post+generic=%3Ftid%3Dsm_twitter_washingtonpost