19th Century Airship Technology for Port Security

fenimor writes "Airships - known today mainly for advertising flyovers at football games - are the core of a new coastal surveillance system in development for the the U.S. Department of Defense. These stationary platforms 25 times the size of a Goodyear blimp will be equipped with an array of cutting-edge equipment for remote sensing, communications, and risk analysis, providing surveillance coverage over a surface area of 500,000 square miles from an altitude of 70,000 feet."