see url: https://en.wikipedia.org/wiki/Northrop_Grumman_RQ-4_Global_Hawk
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The *Northrop Grumman RQ-4 Global Hawk* is a high-altitude,
remotely-piloted
<https://en.wikipedia.org/wiki/Unmanned_aerial_vehicle>, surveillance
aircraft <https://en.wikipedia.org/wiki/Surveillance_aircraft>. It was
initially designed by Ryan Aeronautical
<https://en.wikipedia.org/wiki/Ryan_Aeronautical> (now part of Northrop
Grumman <https://en.wikipedia.org/wiki/Northrop_Grumman>), and known as
*Tier II+* during development. The Global Hawk performs duties similar
to that of the Lockheed U-2
<https://en.wikipedia.org/wiki/Lockheed_U-2>. The RQ-4 provides a broad
overview and systematic surveillance using high-resolution synthetic
aperture radar <https://en.wikipedia.org/wiki/Synthetic_aperture_radar>
(SAR) and long-range electro-optical/infrared (EO/IR) sensors with long
loiter <https://en.wikipedia.org/wiki/Loiter_(aeronautics)> times over
target areas. It can survey as much as 40,000 square miles (100,000 km^2
) of terrain a day, an area the size of South Korea
<https://en.wikipedia.org/wiki/South_Korea> or Iceland
<https://en.wikipedia.org/wiki/Iceland>.
The Global Hawk is operated by the United States Air Force
<https://en.wikipedia.org/wiki/United_States_Air_Force> (USAF). It is
used as a High-Altitude Long Endurance
<https://en.wikipedia.org/wiki/High-Altitude_Long_Endurance>
platform^[2]
<https://en.wikipedia.org/wiki/Northrop_Grumman_RQ-4_Global_Hawk#cite_note-2>
covering the spectrum of intelligence collection
<https://en.wikipedia.org/wiki/Intelligence_collection> capability to
support forces in worldwide military operations. According to the USAF,
the superior surveillance capabilities of the aircraft allow more
precise weapons targeting and better protection of friendly forces. Cost
overruns led to the original plan to acquire 63 aircraft being cut to
45, and to a 2013 proposal to mothball the 21 Block
<https://en.wikipedia.org/wiki/1962_United_States_Tri-Service_aircraft_designation_system#Block_number>
30 signals intelligence
<https://en.wikipedia.org/wiki/Signals_intelligence> variants.^[1]
<https://en.wikipedia.org/wiki/Northrop_Grumman_RQ-4_Global_Hawk#cite_note-GAO-13-294SP-1>
The initial flyaway cost <https://en.wikipedia.org/wiki/Flyaway_cost> of
each of the first 10 aircraft was US$10 million in 1994.^[3]
<https://en.wikipedia.org/wiki/Northrop_Grumman_RQ-4_Global_Hawk#cite_note-:0-3>
By 2001 this had risen to US$60.9 million,^[4]
<https://en.wikipedia.org/wiki/Northrop_Grumman_RQ-4_Global_Hawk#cite_note-4>
and then to $131.4 million (flyaway cost) in 2013.^[1]
<https://en.wikipedia.org/wiki/Northrop_Grumman_RQ-4_Global_Hawk#cite_note-GAO-13-294SP-1>
The U.S. Navy <https://en.wikipedia.org/wiki/United_States_Navy> has
developed the Global Hawk into the MQ-4C Triton
<https://en.wikipedia.org/wiki/Northrop_Grumman_MQ-4C_Triton> maritime
surveillance platform.
