BLOS Capability Enables the RQ-4 Global Hawk to Live Up to Its Name

BLOS Capability Enables the RQ-4 Global Hawk to Live Up to Its Name

Daniel J. Hall, Jr.

ASCI 638 – Human Factors in Unmanned Systems

Embry-Riddle Aeronautical University-Worldwide

June 28, 2014

BLOS Capability Enables the RQ-4 Global Hawk to Live Up to Its Name

The ability to command and control (C2) unmanned aerospace systems (UAS) beyond the line of sight (BLOS) of the operator has greatly expanded the utility of these systems.  BLOS capability has been enabled through the advancement of satellite communications (SatCom), global positioning system (GPS) technology, and long range data links.  One UAS that utilizes BLOS C2 to truly live up to its name is the Northrop Grumman Global Hawk.

The Northrop Grumman Global Hawk has been in development since “1995” (Northrop Grumman Corporation, 2008, p. 2).  With its ability to fly for more than 24 hours at altitudes above 50,000 feet mean sea level (Northrop Grumman Corporation, 2008), Global Hawk operators have used its BLOS capability to set records in long range operations.  According to Northrop Grumman Corporation (2008), “Global Hawk flew 7,500 miles nonstop across the Pacific to Australia on April 22-23, 2001, setting several new world records for UAS endurance” (p 2).

There are several methods available for conduction BLOS operations with UAS.  The employment of ground or air based radio frequency (RF) repeaters is one method to facilitate BLOS operations.  Another method is to capitalize on the ability to skip RF signals off of the atmosphere.  However, according to Avionics Today (2013) the primary method for conducting UAS BLOS operations is via “satellite communications” (para. 4).  Avionics Today (2013) details the use of the Inmarsat satellite communication system to enable BLOS operations:

There’s been new advancements on the SatCom side, particularly with Inmarsat and SwiftBroadband.  These new advances in service and terminals are changing the landscape dramatically.  Inmarsat’s new SwiftBroadband and I-4 satellites have ushered in an era of new smaller, lighter, less expensive terminals that can bring a beyond-line-of-sight data link capability to more UAV types and to more applications. (Avionics Today, 2013, para. 5)

The Global Hawk utilizes several links for satellite communications.  According to Northrop Grumman Corporation (2008), the Global Hawk communication package includes “Ku SatCom Data link, CDL LOS, UHF SatCom/LOS, Inmarsat, ATC Voice, Secure Voice” (p 5).  Specifically, the Ku SatCom Data link, UHF SatCom, and Inmarsat communications links are the components that provide the Global Hawk with its redundant BLOS capabilities.  Satellite communication links are provided for the Global Hawk via several antennas however, the Global Hawk’s distinctive hump just aft of the nose houses a large satellite dish for the primary Ku SatCom data link (Northrop Grumman Corporation, n.d.).

Research and development with BLOS technology offers the potential of greater reliability and flexibility for the UAS community.  Avionics Today (2013) stated, “When they have the capacity for an over-the-horizon type view, it gives them even more of an application across all platforms” (para. 3).  For example, Northrop Grumman recently demonstrated a “unique split link capability for Global Hawk that allows it to send mission data through a satellite link that is independent of the link used for command and control” (Northrop Grumman Corporation, 2014, para. 2).  However, in the author’s opinion, the high cost and restricted access of satellite communications may limit the commercial application of BLOS UAS capabilities for the foreseeable future.

References

Avionics Today. (2013, March 1). UAV communications. Retrieved from http://www.aviationtoday.com/av/issue/feature/UAV-Communications_78540.html#.U7AaLSDD9Ms

Northrop Grumman Corporation. (2008, May). Facts: RQ-4 Global Hawk high-altitude, long-endurance unmanned aerial reconnaissance system. Retrieved from http://www.northropgrumman.com/Capabilities/RQ4Block20GlobalHawk/Documents/HALE_Factsheet.pdf

Northrop Grumman Corporation. (2014, April 3). Global Hawk expands satellite communications capability. Retrieved from http://www.globenewswire.com/newsarchive/noc/press/xml/nitf.html?d=10075411

Northrop Grumman Corporation. (n.d.). Northrop Grumman RQ-4 Block 40 Global Hawk cutaway diagram. Retrieved from http://www.northropgrumman.com/Capabilities/GlobalHawk/Documents/Cutaway_Drawing_GH_Block_40.pdf