Identify an example of an early UAS design (historical, pre-1970s) and compare to a contemporary design (current, 2000s+) that evolved from the early design. Discuss how the two systems are similar, how they differ, and design changes that occurred as the system evolved. What new technology might influence future evolution of the design or system capability?
Army SD-1
In the mid 1950’s, the Army started experimenting with equipping target drones with small cameras for battlefield reconnaissance. They developed the SD-1 (Surveillance Drone) from the Radioplane RP-71 Target Drone. The SD-1 carried a KA-20A daylight camera capable of taking 95 photos or the KA-39A infrared night camera that could take 10 photos. Pilots would launch the drone with rocket-assisted takeoff (RATO), tracked by radar and the pilot on the ground would control the SD-1 through radio commands over the span of a standard 30 min flight. The SD-1 drone combined with its equipment was named the AN/USD-1 and is lauded as the world’s first successful surveillance Unmanned Aerial Vehicle (UAV) (Zaloga, 10). The SD-1 served as a corner stone for many of the technologies used in following years and furthermore served as a precursor for present-day reconnaissance UAVs.
US Air Force RQ-4 Global Hawk
The present-day iteration of the previously discussed Army SD-1 drone is Northrop Grumman’s RQ-4 Global Hawk. The Global Hawk is a high-altitude, long-endurance UAV responsible for intelligence, surveillance and reconnaissance (ISR) missions. It is capable of flying up to 65,000 feet for up to 35 hours at speeds nearing 340 knots. Furthermore, the RQ-4 can process the imagery for an area the size of Illinois in a single mission (Northrop Grumman, 2014). More specifically, the Global Hawk is equipped with an extremely sophisticated sensor suite. The Enhanced Integrated Sensor Suite (EISS) can pinpoint stationary and moving targets with unrivaled accuracy. Furthermore, it can transmit imagery and position information from 60,000 feet and is unprecedentedly clear. The EISS integrates a synthetic aperture radar (SAR) antenna with a ground moving target indicator (GMTI) and a high resolution electro-optical (EO) digital camera and infrared (IR) sensor (Raytheon, 2014).
SD-1 vs RQ-4
The SD-1 and RQ-4 are similar in intent and purpose – both systems are designed for reconnaissance missions. The starting stages of the SD-1 were geared towards use with guided missiles, but eventually evolved into a reconnaissance focused mission; this was further solidified with the addition of the KA-20A/KA-39A cameras (Zaloga, 10). This capability has been further enhanced n the RQ-4 Global Hawk, which has logged more than 8,000 combat hours conducting ISR missions (Northrop Grumman, 2014). While similar in mission, the SD-1 and RQ-4 are different in actual operation. The SD-1 was launched using rocket-assisted take off, while the RQ-4 is powered by a Rolls Royce AE3007H turbofan engine (Northrop Grumman, 2014). This is a stark contrast to the SD-1’s power plant, which was non-existent.
With any system that aspires to mature and increase in ease of use and popularity, the Global Hawk’s capability shrunken down into a smaller operational footprint could definitely influence future design evolution and system capability. This reduced footprint applies to the actual airborne RQ-4 as well as the mission control element (MCE) on the ground at both the home station as well as the MCE in the deployed environment. Furthermore, a reduction in the data lag time would also help with the future evolution of the system as this would reduce the human factors issues inherent in any UAV operation. One of the biggest issues with UAV operation is the responsiveness of the system – the human operator will make a control input on the ground, and it will take a couple seconds for the system to respond. This is something that we as human operators have to be willing to accept when remotely operating aircraft – however, it is not a reason to be complacent about the issue either. Efforts could be placed towards the system programming to reduce the lag time in UAV operation.
References
Northrop Grumman (2014). RQ-4 Block 10 Global Hawk. Retrieved from http://www.northropgrumman.com/Capabilities/RQ4Block10GlobalHawk/Pages/default.aspx
Northrop Grumman (2014) RQ-4 Global Hawk: High Altitude, Long-Endurance Unmanned Aerial Reconnaissance System Fact Sheet. Retrieved from http://www.northropgrumman.com/Capabilities/RQ4Block10GlobalHawk/Documents/HALE_Factsheet.pdf
Raytheon (2014). Global Hawk Enhanced Integrated Sensor Suite. Retrieved from http://www.raytheon.com/capabilities/products/globalhawk_iss/
Zaloga, S.J. (2008). Unmanned Aerial Vehicles: Robotic Air Warfare 1917-2007. Oxford, U.K.: 2008.
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