The
Northrop Grumman RQ-4 Global Hawk is an
unmanned (UAV)
surveillance aircraft. It was initially designed by
Ryan Aeronautical (now part of
Northrop Grumman), and known as
Tier II+ during development. The Global Hawk performs a similar role as the
Lockheed U-2. The RQ-4 provides a broad overview and systematic surveillance using high-resolution
synthetic aperture radar (SAR) and long-range electro-optical/infrared (EO/IR) sensors with long
loiter times over target areas. It can survey as much as of terrain a day.