Introduction
Predator B (MQ-9) is one of the most
popular military UAV (Unmanned Aerial Vehicle) in the world. Currently, this
aircraft has been deployed by the U.S. Air Force, U.S. Department of Homeland
Security, NASA, the Royal Air Force, the Italian Air Force, the French Air
Force, and the Spanish Air Force (General Atomic Aeronautical, 2016). The
primary mission for this unmanned aircraft is to hunt and interdict emerging
targets. The secondary mission is to act as an intelligence, surveillance and
reconnaissance tools, employing sensors to provide real-time data to commanders
and intelligence specialists at all levels (Global Security, 2016).
Platform
and Payload
Predator B has an endurance of over 27
hours, speeds of 240 KTAS, can operate up to 50,000
feet altitude. It has a 3,850 pound (1746 kilogram) payload capacity that
includes 3,000 pounds (1361 kilograms) of external stores. For stability and
reliability, the aircraft is equipped with a fault-tolerant flight control
system and triple redundant avionics system architecture (General
Atomic Aeronautical, 2016). Although it is unmanned, yet the design is meeting
and exceeding manned aircraft reliability standards.
To achieve fuel efficiency and improve
performance, the Predator B is powered by the flight-certified and proven
Honeywell TPE 331-10 turboprop engine with integrated Digital Electronic
Engine Control (DEEC) (General Atomic Aeronautical, 2016). The aircraft is designed
to be modular for easy disassembly and assembly on site. More importantly,
spares can be replaced easily to reduce ground time. In order to perform
surveillance tasks remotely, the aircraft is equipped with Electro-Optical/
Infrared (EO/ IR), Lynx Multi-mode Radar, multi- mode maritime surveillance
radar and Electronic Support Measures (ESM) (General Atomic Aeronautical,
2016).
Line-of-Sight
(LOS) and Beyond Line-of-Sight (BLOS) Operation
The UAS (Unmanned Aerial System) consists
of 5 main components. They are:
- Aircraft
- Satellites
- Ground Control Station
- Satellite Uplink Vehicle
- Surveillance targets
The
aircraft can be remotely piloted or can be programmed to fly autonomously. In
view of this, the communication or data link between unmanned aircraft and
ground controller is utmost important. To achieve this, C-Band is used for
line-of-sight data link control. It uses 3.7 to 4.2 GHz
for downlink and 5.925 to 6.425 GHz for uplink. The lower frequencies that C
Band uses perform better under adverse weather conditions (Tech-FAQ, 2016).
BLOS is defined as the distance of 600
miles (966 km) over the horizon between aircraft and ground control station.
Controller uses Ku-Band to communicate with aircraft via satellites instead.
The Ku band is a portion of the electromagnetic spectrum in the microwave range
of frequencies ranging from 11.7 to 12.7 GHz (downlink frequencies) and 14 to
14.5GHz (uplink frequencies) (Tech-FAQ, 2016). Also, the video link from
aircraft cameras are downlink to ground controllers and front line personnel
using Ku band.
Additionally, when operating BLOS, two
different GCSs are required during the hand-off procedures. The launch and
recovery crew element (LRE) launches the aircraft from the operating region and
the mission control element (MCE) takes control of the flying aircraft. Both the
LRE and MCE crews must synchronize GCSs with the same parameters entered into
the flight computers to set up system properly. Scenario such as one GCS has
the gear handle in the down position and the other GCS has the gear handle in
the up position will trigger an over speed condition on the gear.
Advantage
of LOS/ BLOS
LOS
and BLOS operations allow UAS missions to be monitored and controlled remotely. Advantage
of UAS deploying satellites for up and down link enable integration of UAS into Next
Generation (NextGen) platform. It allows sharing of national air space between
unmanned aircraft and other manned or unmanned aircraft safely. The FAA has
designated C2 communications for point-to-point networking if both aircraft are
equipped with ADS-B (Automatic
Dependent Surveillance- Broadcast) (Geiver, 2014). Another advantage when operating
within LOS is the ability for the pilot to have better situational awareness of
environment when aircraft can be seen.
Human
Factors
One
of the disadvantages when operating BLOS is the momentary delays caused by the transition
from C band to Ku band due to satellite relay. The pictures and video data
received from the cameras are sent to the satellite and downlink to the
Satellite Uplink Vehicle (Dee, 2014).
The delays might lead to distortion of data. Momentary discontinuation of
information during battle against enemies could be catastrophic.
Another limitation of deploying Predator B is that the pilots can only view images on heads-up display through cameras mounted on the nose of aircraft. It allows pilot to see objects at the front, side and aft of the aircraft only. Pilot has limitation viewing objects above the aircraft. Also, multi-spectral targeting pod (MTS), which has multiple cameras and can be slewed 3600 around the plane, is mounted below the aircraft nose. The FOV (field of view) of the nose cameras is limited to 300. Although the MTS has multiple levels of magnification, when zoomed-in, it gives an extremely limited “soda-straw” perspective of the battlefield (Wheeler, 2012).
Another limitation of deploying Predator B is that the pilots can only view images on heads-up display through cameras mounted on the nose of aircraft. It allows pilot to see objects at the front, side and aft of the aircraft only. Pilot has limitation viewing objects above the aircraft. Also, multi-spectral targeting pod (MTS), which has multiple cameras and can be slewed 3600 around the plane, is mounted below the aircraft nose. The FOV (field of view) of the nose cameras is limited to 300. Although the MTS has multiple levels of magnification, when zoomed-in, it gives an extremely limited “soda-straw” perspective of the battlefield (Wheeler, 2012).
Conclusion
The
deployment of Predator B for multiple missions improves performance efficiency and
cost saving. More importantly, it reduces pilot’s exposure towards hostile
environment such as high altitude, flying above enemy territories, executing
repetitive and monotonous tasks for long period of times. But UAV has its
shortcomings. Lack of pilot’s situational awareness, sensory and tactile
feedback from aircraft movement are some of the challenges that require attention.
Camera viewing angle from Predator B leads to limited visual perception of
pilot. In turn, it delays decision making process and affects performance
efficiency. More crucially, it compromises the safety of aircraft and personnel
or property underneath aircraft flight path.
Reference
Dee, L.
(2014, November 16). UAS Human Factors. Unmanned Aircraft System beyond Line of Sight.
Retrieved from http://aboutuas.blogspot.com/2014/11/unmanned-aircraft-system-
beyond-line-of.html
Geiver, L.
(2014, December 18). UAS Magazine. NextGen, FAA seeks UAV study participants for beyond
line of sight. Retrieved from http://www.uasmagazine.com/articles/908/nextgen-faa-seek-uav-study-participants-for-
beyond-line-of-sight
General
Atomic Aeronautical. (2016, June 25). Predator B RPA. Retrieved from http://www.ga-
asi.com/predator-b
Global
Security. (2016, June 25). MQ-9 Reaper. Retrieved from http://www.globalsecurity.org/military/systems/aircraft/mq-9.htm
Tech-FAQ.
(2016, June 25). C Band. Retrieved from http://www.tech-faq.com/c-band.html
Wheeler, W.
(2012, February 12). The MQ-9's cost and performance. TIME, Retrieved from
http://nation.time.com/2012/02/28/2-the-mq-9s-cost-and-performance/
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