Military drone launch

Military drones continue to take flight

Drones are becoming ever more important in frontline conflict. Here we look at the many ways in which these complex machines have infiltrated the combat arena.

The role of the aircraft in modern military actions is altering, and at a dramatic rate. Traditionally, the air force would provide the backbone of any military air campaign – both from a reconnaissance standpoint and for strike operations, but recent conflicts in Iraq and Afghanistan have highlighted the growing use of Unmanned Aerial Vehicles (UAV). This new approach is driven by a variety of factors including operational requirements, costs and pilot safety. And without a doubt it is a lucrative market with the industry estimated to be worth £5bn this year.

The military market for UAVs is growing year on year. At the turn of the century there were just a small handful of UAVs in the US military inventory. Now, ten years later, there are several hundred of the larger variety – Predator and Reaper – with the US Army operating thousands of smaller tactical and hand-launched systems.

According to General Atomics Aeronautical Systems, the demand for its Predator and Gray Eagle-series continues to increase exponentially on a yearly basis. 'In 2006, our family accumulated 80,000 flight hours,' Kimberly A Kasitz, General Atomics Aeronautical Systems, says. 'In 2010, that number surged to 375,000 flight hours.'

UAVs proved their worth in the recent conflict in Libya and even hit the headlines in June when the first NATO casualty in the engagement was a Northrop Grumman MQ-8 Fire Scout, shot down by Gaddafi's forces.

The US is not alone in its use of UAVs. Israel has its own Heron TP UAV while China has the Silver Eagle. 'Even in the UK we have seen the demise of obsolete artillery-spotting Phoenix UAVs and the inception of the Watchkeeper, a larger and infinitely more capable system to provide Intelligence Collection capabilities for the British Army as a whole,' Mike Humphreys, head of requirements integration and campaign support within the military air and information branch of BAE Systems, says.

The benefits of UAVs are readily apparent. They are relatively cheap to acquire, operate and maintain when compared to a fast jet or larger intelligence acquisition systems. 'This is not to say that they are more capable across the military operational domain, but rather that in current, insurgency-based operations, these advantages, coupled with very long endurance by comparison to jet-powered and manned platforms, make them ideal platforms to deliver decisive military effect against these difficult, fleeting targets,' Humphreys adds.

As the technology associated with UAVs develops, their role is changing. Initial platforms were mere carriers for full-motion-video sensors, but they have been weaponised, carry more sensors and integrate effectively with the battle space.

It is not just the role that is changing for these systems. The nomenclature 'UAV' has evolved to 'UAS' – Unmanned Aircraft Systems. UAS denotes a 'system of systems' whereby the air vehicle is equipped with multiple payloads, or systems, to satisfy a variety of mission sets. 'UAVs have gone from being at the cheap, cheerful and thus arguably the disposable end of the military air platform range, to altogether more capable, complex and costly,' Humphreys explains. 'The advent of Remote Site Operations has also seen the advent of crews living in Las Vegas, but fighting the air war over Iraq. Platforms have become bigger, faster and weaponised.

'The man-in-the-cockpit still presents a certain military capability required in high-intensity or short-notice events, but for most other applications the UAV is now a cost-effective means to deliver capability in enduring conflicts.'

The mainstay of the US military is General Atomics' Predator series. The system first entered service over 15 years ago, but is still the pillar for many military operations. 'Predator routinely performed line-of-sight missions, and later it incorporated satellite communications, allowing it to perform beyond-line-of-sight missions,' Kasitz says. 'During its first few years in operation Predator was viewed strictly as an Intelligence, Surveillance and Reconnaissance (ISR) asset. Later, in 1999, it began laser designating for other attack aircraft. In 2001, its mission evolved again, tasked with weapons release.'

UAV control

There are two recognised control systems for UAVs – line-of-sight and beyond line-of-sight. Line-of-sight command links effectively link the ground controller direct to his platform like a model aircraft, albeit the datalink systems are far more complex and digital.

'Digital datalinks maintain the link between ground operator and aircraft, either by direct line-of-sight, or at greater ranges using satellite systems,' Humphreys adds. 'When the link is broken, which does happen, albeit temporarily, in most cases and even then only for very short, sub-one-second periods, the platform is programmed to complete a series of automatic actions to re-establish the link or, failing that, to return to base and land.'

Larger UAVs now operate beyond-line-of-sight, with operators controlling platforms through satellite links from several thousand miles away. 'Clearly this confers some lag in the system, which for the current crop of platforms, many of which are 'flown' with conventional controls such as joysticks, can be an issue,' Humphreys says. 'These remotely piloted air systems do, however, integrate effectively into modern air management systems. More modern approaches replace the pilot with operators and computer interfaces, which replicate the Human-machine interfaces of computer games. We may expect this to change again, to direct voice command and other forms of intuitive control where the operator instructs the air vehicle to undertake a task, rather than guiding the platform directly.'

Customer demand

General Atomics report that customer demand for sensors, particularly the Lynx Multi-mode Radar, continues to grow. 'Lynx is a long-range, wide-area surveillance sensor that is particularly valuable to our customers for detecting time-sensitive targets and moving vehicles,' Kasitz says. 'It features photographic-quality resolution and delivers an all-weather capability.

'Customers are also interested in high-definition [HD] video. Our current video compression squeezes 560 x 480 pixel resolution images into 3.2MBps at 30 frames per second. The new HD compressor will produce greater resolution images (1280 x 720 pixels), increasing data to 6.4MBps.'

Humphreys agrees that more and better sensors, both from a fidelity perspective and also field-of-view terms are driving innovation. 'As far as the actual UAV system goes, autonomy is increasingly in vogue, both to analyse the huge amounts of data, and to reduce the training requirement and skill sets required of the crews,' he adds.

One challenge that may hinder the use of UAVs is access to airspace as they lack effective sense-and-avoid technologies. 'Currently, access is limited to segregated airspace over sea or in military ranges,' Humphreys says. 'Access to airspace will see an exponential rise in the number of civil applications for which UAVs are used. However, with this rise the available bandwidth over which UAVs may be controlled or pass their data will be increasingly constrained.

'The policies and processes which regulate the use of the EM spectrum will need rapid and imaginative revamp to enable the market to gather pace in a controlled fashion, and the use of compression technologies to limit the need for bandwidth will increase in step with the market.'

The future

In the short term there is expected to be gradual innovation in UAVs that will optimise their current generation and style. However, the next generation of vehicles will be far more autonomous and many experts predict that in 20 years they will run their own missions with minimal interaction with human controllers, and only defer to them for a human decision driven by regulation, law or ethical considerations. 'Platforms will emerge to capture the advantages of long-persistence or high-altitude operations – lighter-than-air – and in so doing some functions currently undertaken by satellites might well move onto cheaper, high-flying UAVs,' Humphrey concludes.

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