Patriot batteries are comprised of radar and control systems, launcher stations, and interceptor missiles, making them one of the world's best air defense systems capable of intercepting a variety of threats.
Over years of flying, it had been drilled into the crew to pull back on the controls when such an alarm sounded, but on this occasion the pilot took no action. The crew were prepared for their system to make spurious warnings and knew from experience they were still flying at a safe altitude.