The use of UAVs in the military context is a great headline grabber, but a wealth of computer technology is really helping the sector take off in much more creative directions. How will we be employing drones in the upcoming decades?
They're being used for everything from terrorising terrorists to monitoring tuna stocks in the ocean. Children are piloting them with smartphones, and law-enforcement officials are using them to track down and capture most-wanted targets. Unmanned aerial vehicles (UAVs), more popularly known as drones, have developed rapidly in recent years, thanks to some largely untrumpeted developments in information and communications technology.
The terms 'UAV' and 'drone' cover a multitude of vehicle types, and the situation is quickly approaching where sub-definitions will be needed to keep up with the variety of products on the market.
The UAV market continues to grow rapidly; in some respects it's a bit of a free-for-all, as inventive and innovative engineers and designers launch their own peculiar take on 'drone chic'. Then there's the question of regulation, and where and when the current crop of products are legally entitled to fly - and who is liable should they fall out of the sky with disastrous results.
Americans are leading here on multiple fronts. The US Department of Defense (DoD) classifies UAVs into five groups, based on size, weight and capability. Group 1 consists of vehicles less than 20lb, flying less than 1,200ft. Group 2, between 21 and 55lb, flies below 3,500ft. While group 3 spans a far larger window, with weights up to 1,320lb. Groups 4 and 5 are reserved for the heavy-hitters: long-range, heavy-endurance craft. Whereas lower-class vehicles give you agility and the ability to hand-launch, higher-class UAVs can fly higher, for longer; but even in the lower classes, endurances are still respectable. The class two Boeing ScanEagle craft used for surveillance by the Canadian military in Afghanistan, for instance, can conduct missions of 13 hours.
As director of strategic UAV campaigns at Honeywell Defense and Space Prabha Gopinath points out, higher classes mean heavier payloads in respect to on-board technology. "These now include high-definition cameras with heavy lenses, chemical sniffers, and imaging cameras that can look through a few inches of dirt," he explains, along with sensors designed to look in various directions. Such sophisticated and powerful utilities usually come with a weight penalty that can comprise other performance attributes.
Heavier payloads can also mean weapons, of course. The Global Atomics Predator is perhaps the best-known weaponised UAV, having carried out many missions in Pakistan. As designers try to squeeze more payload into vehicles with better capabilities, they must labour over size, weight and power (SWAP) ratios. "There are efforts to shrink the size of UAVs, and the ability to do more tactical and agile flight," says Tim Chung, assistant professor of systems engineering at the Naval Postgraduate School. "There is a huge investment in understanding how to increase the power density." Researchers are working on capturing wind energy from dynamic soaring techniques and to take more advantage of thermals, Chung says: "And of course, there are solar cells along the wings." Designers are also exploring emerging battery technologies, including hybrids.
Jeremy Laliberte, assistant professor at Carleton University and project manager for the Capstone UAV Aircraft Design Project, says that the real cutting-edge work in the drone sector is happening in the lighter, smaller UAV groups. "You're going to see that divergence, where the big stuff will be like any other airplane," he predicts. "Where things get interesting is with the smaller craft. With small 20-30lb UAVs, you can start exploring more materials, like 3D printing and integrated antennas."
Other technologies such as all-electric propulsion and fuel cells become important here too. "That's the nice thing about the small UAVs: they could become a test bed for technologies that could find their way onto manned aircraft," Laliberte continues.
This technology starts with military applications before making its way into the commercial space. For years, the main uses of UAVs were military ones. Since the Second World War, UAVs have gradually developed from glorified flying bombs into more sophisticated vehicles used for surveillance and targeted attacks.
UAV pros and cons
Israel led the field in UAVs for military purposes, demonstrating their successful use in the Lebanese conflict in 1982, which in turn did much to encourage the US to invest in this field. Now the DoD's interest in UAVs is escalating. The 2012 DoD budget requested $3.9bn for UAV development and procurement – an almost six-fold increase since 2001. It will spend over $37.5bn on them over the next four years.
The appeal of UAVs for the military lies partly in saving money, and partly in saving pilots, and probably in public relations derived from both of these factors. The Northrop Grumman Global Hawk RQ4 UAV has a range of 5,400 nautical miles, and is designed to stay aloft for days, with the pilot safely ensconced at a remote ground base. However, the pros and cons of manned versus unmanned spy aircraft are not as clear-cut as they might at first appear.
Some sources claim some Global Hawks cost about $35m each, while developments can push the total price to $218m. BAMS, a proposed derivative for use by the US Navy, could cost even more.
Why do these aircraft cost so much? Part of the overhead stems from the fact that some 54 per cent of the Global Hawk's cost lies in its payload. "The drone is just a vehicle: it is the data that it can collect that's important," explains Wayne Crowe, executive director of Unmanned Systems, a non-profit consortium of UAV companies based in Canada. "You must put the sensors and data together."
It goes beyond even that. Outside the drone and the payload, the UAV relies on a communication system to connect it to ground crew that must be secure and reliable. And once it gets its data back to the ground, it must be analysed. What started out as a spy-in-the-sky is now verging on something akin to a flying enterprise ICT infrastructure, except that we are still at the stage when much of the hardware and software is bespoke (therefore expensive).
Communications systems are perhaps the most challenging. High-speed links are necessary for communicating with UAVs that may be on a mission halfway round the world, and designers must also allow for the fact that even the best communications links may break. A single Global Hawk requires a 500Mb/sec link, which is estimated to be five times more than the entire US military used during the 1991 Gulf War.
The issue of UAV regulation may come further to the fore if UAV-sourced evidence is used in criminal cases.
Some police forces are exploring using small quad-motor rotor units to get forensic aerial overviews of a crime scene. Seattle police have a 3lb Draganfly X6 DraganFlyer UAS (unmanned aerial system, as is its preferred designation) that can stay aloft for 20 minutes and beam video and thermal imaging data to operators on the ground.
Texas police are using $300,000 Vanguard ShadowHawk UASs capable of firing tazers and rubber bullets, although the weapons' capabilities have not as yet been deployed. US Customs and Border patrol officials are also using larger drones on the US-Mexico border.
Companies are emerging to target these markets. "We take technology that's funded by the military, and we can put it in law enforcement for a tenth of the cost," says Chris Miser, founder of Falcon UAV. The company offers a basic airframe for $13,000, with a $1,000 autopilot option and a ground control station for under $3,000.
UAVs meet Big Data
Surveillance and data collection is a key function of UAVs that spans all these applications. "It puts eyes in the sky," says Miser, adding that a drone can hover above a known individual's house, or be used for search-and-rescue operations.
Back-end data analysis for applications such as these is a critical part of the UAV ecosystem. In the military space, data processing becomes even more critical.
"The biggest problem is not putting better payloads in the sky," says Honeywell's Gopinath, "it is dealing with the massive amounts of data that comes from these birds." Predators can deliver a terabyte of data from their sensor package for every 60 minutes that they spend in the sky. Standard commercial database software from companies like IBM or Oracle can then be used to interpret the data, using standard relational or object-oriented techniques.
However, backlogs are still building. "How to fuse that information and disseminate it has become a major issue," explains Jeff Kline, director of CRUSER – the Consortium for Robots and Unmanned Systems Education and Research. Like enterprise IT, UAV operations face ever-escalating data sets. "We are collecting more information than we can process now," Kline also admits.
The trick involves distilling the data upstream, and displaying it so that humans are not overwhelmed. One approach to this is to process a lot of the data on-board the UAV itself. "We're trying to figure out what we will let the robot do," Kline adds, "and it's still an open question."
This processing autonomy can be implemented at various levels, starting with none at all. "You could just send down all of the raw data," says the Naval Postgraduate School's Chung. "Or you could find all the cars and send thumbnail shots down."
But things can become far more nuanced. A drone might look only for red cars, is a possibility that Chung posits: "We have many researchers looking at image processing algorithms... The question is, at which level you want a UAV to make an executive decision? At a 'red vehicle' decision level? Or where it decides that an individual [on the ground] is doing a very bad thing?"