Military Drone & Bird Radar: Defending Air Bases Against Airborne Threats

Throughout the United States, over 20,000 wildlife strikes are reported each year. Over 97% of these strikes involve birds, costing hundreds of millions of dollars in damage to critical military assets. Meanwhile, the drone threat continues to grow. In 2020, the Federal Aviation Authority (FAA) received 1,633 reports of unauthorised drone activity in US air space.

As the U.S. Air Force (USAF) continues to optimize its operational assets during challenging times, the need to protect military assets has never been higher. Advanced radar provides the situational awareness air bases need to detect airborne threats and reduce downtime.

Over the last few years, we’ve seen a plateau and even a slight decrease in the global number of active aircraft. However, the United States of America maintains the strongest Air Force in the world by an impressive margin.

As of late 2021, the USAF is composed of 5,217 active aircraft, making it the largest, the most technologically advanced, and the most powerful air fleet in the world. What's more, the United States Navy, Army, and Marine Corps are close behind, bringing the United States' total available military aircraft to 13,247. This is larger than the next five largest air fleets, combined.

But that fleet is under pressure from budget restraints and new investment opportunities. Last year, the USAF announced that it would retire more than 200 legacy aircraft with its fiscal 2022 budget request. The U.S. Air Force predicts this will free up $1.3 billion in savings, which it will reinvest in cutting-edge technologies like its sixth-generation fighter and hypersonic weapons. The budget request also revealed that proposed procurement costs fell from $26.1 billion to $22.9 billion.

Through its Next Generation Air Dominance program, the US plans to use digital engineering to create state-of-the-art assets that will drop the overall cost of modernizing and maintaining aircraft. Part of this plan requires the Air Force to spend most fighter program costs upfront, instead of at the end of the aircraft’s life.

The new F-35 is the tip of the spear in these new plans. With its emphasis on warfighting and defensive operations, the F-35 will play a crucial role in USAF’s future. But it’s an expensive piece of kit that’s particularly prone to bird strikes and drone threats.

The F-35 features a sophisticated EOTS (Electro-Optical Targeting System) that’s mounted under the nose. From this exposed position, this expensive feature is more vulnerable to damage from birds and drones.

As a stealth-capable aircraft, the F-35 shares the same problem as other stealth aircraft – damage to the exterior can impede an aircraft’s stealth functionality. It also removes specialised coatings that reduce drag and noise. One scratch could render the aircraft unfit for operations.

Finally, as with all single-engine aircraft, a bird strike or drone collision in the engine can be disastrous, especially at a time when mission capability rates need to improve.

What does this all mean? More expensive airplanes, paid for upfront in a smaller fleet that already only operates at a 70-80% mission capable rate. In this environment, asset availability is critical, which is why interest in preventative measures such as bird and drone detection radar is on the rise.

It’s a constant challenge to prevent bird strikes on military aircraft. Every year, USAF aircraft sustain around 4,000 strikes. Fighters fly fast, low, and perform tens of cycles in short flurries of activity, such as touch-and-goes, training circuits, and QRAs (quick reaction alerts). High cycle rates at low altitudes increase the risk of a bird strike because 90% of incidents occur between 0 and 3,500ft.

Three-quarters of bird strikes involve the wing or engines. So, combat aircraft, which often have one engine and comprise 20% of the USAF’s inventory, can be rendered ineffective instantly. Between 1995 and 2019 the cost of bird strikes (excluding injuries) was almost $818m.

USAF Flight Safety (SEF) Offices employ integrated wildlife hazard management operations, consistent with requirements and guidance in AFI 91-212, Bird/wildlife Aircraft Strike Hazard Program Management.

Current USAF policy requires sites to have a Bird/wildlife Hazard Warning System. This unit-defined system requires a tiered approach to local flight restrictions based on Bird Watch Conditions; an observed wildlife occurrence that could affect flight operations, resulting in a wildlife strike event.

Under an increased Bird Watch Condition, aircraft operations can be restricted or terminated based on the threat posed by wildlife, visually observed by ground personnel, Air Traffic Control, and/or aircrews.

Air base bird detection is a multi-person challenge that requires 24-hour surveillance. In a country with as diverse a geography as the USA, each air base will have its unique challenges and species of bird to watch out for. However, there are several universal challenges.

Line of sight

Relying on human observation to determine a Bird Watch Condition is exclusively limited to the range of sight for air operations personnel. Humans with an unobstructed view have a line of sight of about 3 miles, but the range at which you can detect a single bird is much shorter.

The other challenge is that humans can’t see everywhere at once. So even if equipped with binoculars, personnel looking in the wrong direction will never see an oncoming bird strike.

24/7 surveillance

It’s impossible to maintain 24/7 surveillance around a military air base with human observers alone. Rain, fog, and low light reduce visibility. Fatigue is another challenge. Even the most diligent and tireless ground teams need the occasional break, and that can leave gaps in your coverage.

Weather

Rain and fog can have as big an impact on detecting threats as it does on flight operations. Even if equipped with cameras to cover an air base, bad weather can seriously limit your ability to detect birds.

Night

Bird Watch Conditions can normally only be set during diurnal air operations because confirming bird activity at night is impossible without enhanced detection equipment. This seriously limits the ability of air bases to perform night-time operations and training without increasing their risk profile.

Drones

Not everything flying into your airspace is a bird. The rise in drone activity around military installations has risen exponentially in recent years. This creates an additional challenge because the prevention methods for dealing with drones are different than those used against birds. You need to know the nature of the threat.

Full situational awareness

The combination of drone and avian threats to air bases has increased the minimum threshold of suitable countermeasures. Relying on teams of people and visual cues is no longer suitable for protecting today’s air bases.

To protect vital military assets and maintain operational readiness, air bases need full situational awareness of their airspace. Height information of every target at any time could make the difference between a strike and a miss. Not only does this act as an insurance policy against an expensive fleet, but it also gives site personnel complete understanding of the space they’re charged with guarding.

Forecasting

Cancelling operations due to weather costs the USAF both time and money, which is why it uses the best weather forecasting tools available. Forecasting bird behavioral patterns provides a similar level of coverage. But to do this, air bases need a way to identify species, gather data, process, and share it.

Effective detection technology enables better preventative actions. In today’s market, there are a variety of detection solutions to spot incoming birds, including:

• Optical Sensors (cameras and crew)
• Radar

Optical sensors

Cameras help to reduce bird strikes by monitoring birds visually. They’re a cost-effective solution best suited to smaller sites. The larger the site, the more visibility you need. Many air bases employ specialist teams to monitor large open spaces, such as runways, where mounting a camera would be inefficient.

Cameras use imaging to provide coverage. Ground teams can use this information to detect birds and record bird strike incidents – which is essential to create a clear record of a specific event.

However, the sophistication of camera technology leaves a lot to be desired. While operators can use infrared and thermal imaging can be used to detect bird species, they aren't widely used – chiefly due to the effects of adverse weather conditions on performance.

But whether it’s a camera or a crew with binoculars, they all suffer the same two problems: visual range limitations and scope.

Optical sensors are only effective at monitoring the area they’re looking at. And when you consider a space the size of an air base, with aircraft moving around all the time, you need a considerable amount of visual cover. If a bird doesn’t cross its line of sight, an optical sensor won’t spot it.

Radars

Bird detection radars are a powerful tool for detecting birds that use data to perform risk analysis and environmental impact assessments (EIAs). Over time, the technology gathers detailed scientific data on bird movements around your site.

Radars can detect and log hundreds of birds at once, including their size, speed, direction, and flight path. This makes them the ideal solution for large USAF sites that span a wide area. In addition to their superior range, operators can also integrate avian radars with other systems to trigger warnings or preventative action.

Bird detection radars are ideal for covering large sites, such as air bases. They’re excellent for understanding bird movement, helping site personnel perform risk analysis, and confidently setting Bird Watch Conditions.

Radars continuously measure the number of birds that enter a particular area. They’re capable of initiating alerts before threats become visible and when birds cross a designated threshold. They take many factors into account when creating alerts, including wind direction, bird behavior, time of day, and the season.

Radars detect activity day or night. You can also configure them to operate in a variety of challenging environments – from deserts to offshore sites.

The continued commercialization of drones has made them more affordable, easier to obtain, and simpler to fly. But while this opens the skies to a new group of people, it also poses a significant threat to military air bases.

In 2017, General Mike Holmes implored congressional authorities to do more to counter the growing drone threat. Citing two separate incidents, he recounted how one small drone entered a US air base unchecked, while another had a near-miss with an F-22.

Direct collisions between small drones and aircraft can cause serious damage. A University of Dayton experiment conducted in 2018 mimicked a mid-air collision between a 2.1lb DJI Phantom 2 and a Mooney M20. The results were eye-opening. As well as expelling a large amount of debris, the collision penetrated the wing, damaging the main spar.

It’s not only accidental collisions that pose a threat to military operations. From espionage to aerial assaults, drones have become a staple of modern warfare. Even relatively cheap, consumer drones can carry payloads of up to 9lbs. And military-grade equipment can hold significantly more. This makes them the perfect tool for launching airborne attacks against military targets.

FAA regulations prohibit drone activity around national security-sensitive facilities, including:

• Military airbases (that are designated as Department of Defense (DoD) facilities.
• National landmarks, such as the Statue of Liberty.
• Critical infrastructure, such as nuclear power plants.

This covers all operations up to 400 feet above ground level.

To shore up its policies further, the Pentagon unveiled its Counter-Small Unmanned Aircraft Systems Strategy in January 2021. This document aims to develop a common information-sharing architecture, synchronize counter-drone technology investment, and establish joint protocols across the US armed forces.

Nonetheless, many feel more must be done to counter the growing drone threat.

Marine Corp General Kenneth F. McKenzie Jr calls the proliferation of small, cheap drones the “most concerning tactical development” since the invention of the improvised explosive device (IED). Drones are small, fast, and difficult to track. And this presents unique challenges to military air bases.

Detection & tracking

Traditional radar systems were designed to detect piloted, long-distance aircraft and other objects with a large radar cross-section (RCS). Drones, by contrast, are small. Most consumer drones have an RCS comparable in size to a bird. Without the right tools, it can be difficult to detect and track drones that enter your airspace.

Differentiating between airborne threats

Even if a traditional radar can detect small, fast-moving objects, few can tell them apart – due to the similarities in their RCS signatures. This causes confusion which, in turn, can lead to false alarms and wasted time. Specific airborne threats require specific countermeasures.

Intent

Unintentional disruption and collisions are only the tip of the iceberg when it comes to the drone threat. Unlike birds, malicious pilots can launch deliberate attacks on military targets. US forces in Iraq experienced this first-hand earlier this year when two drones carrying a payload of explosives targeted an Iraqi military base housing US troops in western Anbar Province.

Operators must establish the intent of potential threat actors as early as possible to organise an appropriate response.

Drone swarms

Shenzhen High Great Innovation Technology Development Co., Ltd. set a new Guinness World Record for most unmanned aerial vehicles (UAVs) airborne simultaneously in 2021 when 5,164 UAVs took to the skies together. It’s an impressive spectacle and a powerful demonstration of the technology’s capabilities. But it also illustrates the threat they pose to military air bases.

To prepare its forces for the rising drone threat, the US Army simulated a drone swarm attack during a training exercise in 2022. The simulation involved 40 quadcopters equipped with cameras, multiple integrated laser engagement systems (MILES), and lethal munition capabilities. 

Most radars can't keep track of multiple fast-moving targets. Even a swarm of 100 drones is enough to overwhelm a military base.

Autonomous drones

Typically, pilots use a control unit to operate their drones. The unit transmits a radio signal to the drone which relays the pilot’s instructions. And it’s these signals that detectors use to track drone activity.

More recently, we’ve seen the rise of autonomous drones that don’t require a control unit or real-time commands to function. No control unit means no radio waves, and this presents a serious problem for air bases that require full situational awareness to protect their assets.

Military air bases use a mixture of technologies to neutralize drone threats. These fall into two categories:

1. Detection & monitoring
2. Mitigation

You can learn about counter-drone technologies in our comprehensive guide. But here are four of the most important.

Radio frequency (RF) analyzers

RF analyzers use one or more antennas to intercept the radio signals that pass between a drone and its control unit. They typically come in two categories: direction finders and RF signal decoders.

Some can identify common makes and models, while more advanced systems can identify the MAC addresses of the drone and triangulate its position – as well as the position of the operator, in some cases.

Radar

Drone detection radar offers the best range and widest coverage of any detection solution. Traditional radar emits a signal that reflects off any objects it encounters. The antenna then listens for the echo and uses this information to detect and track drones.

As a result, radar is unaffected by weather and low visibility, can track multiple targets, and, unlike human observers, never rests. Purpose-built, 3D drone radars can also distinguish between birds and drones to provide full situational awareness – the cornerstone of an effective early warning system.

Nets and guns

Nets might seem like a relatively low-tech option, but they’re one of the most effective for stopping drones. They work by prohibiting the drone’s rotor blades and quickly bringing the target to the ground.

There are several ways you can bring a net into contact with a drone, including:

• Handheld, shoulder-mounted, or turret-mounted net cannons
• Net cannons equipped to your own drones
• Hanging nets deployed by a ‘net drone’

RF jammers

Radio Frequency (RF) Jammers transmit large amounts of radio energy toward an incoming drone. This masks the controller's signal which causes the drone to either:

• Make a controlled landing in its current position
• Return to its pre-programmed home location
• Fall uncontrolled to the ground
• Fly off in a random direction

The technology is also versatile. Depending on your requirements, you can get static, mobile, or handheld RF jammers.

Radar is the ideal solution for detecting drone threats around sensitive sites, like military air bases.

Combining multiple units into an integrated radar network gives you an uninterrupted, 360° view of your airspace. This allows you to accurately classify, monitor, and track drone activity – in any conditions, 24/7. Not only is this vital for reducing operator workload and eliminating false positives, it provides the full situational awareness you need to organize an effective response.

First to trial avian radar for the RAF

Located at the Moray air base, RAF Lossiemouth is a coastal station that’s particularly vulnerable to bird strikes. It’s also surrounded by several pig farms – another bird attractant. Project Winchell is designed to help protect operations. And, after a successful 18-month trial with Robin’s MAX^® avian radar, we’ve now entered a 5-year contract with RAF Lossiemouth.

MAX^® provides real-time height and positional information of airborne targets, tackling the threat of bird strikes in a more strategic way to reduce the danger and impact of bird strikes at military air bases.

Bird radar in action at RAF Lossiemouth

On the 10^th November 2021, RAF Lossiemouth’s new bird radar capabilities were put to the test. At 17:11, while an RAF Lossiemouth aircraft (call sign Sierra) was in-bound for an ILS approach, MAX^® detected potentially hazardous bird activity over runaway 23…

17:11

Sierra in-bound for an ILS approach. Radar detects a high bird return over the 05 cable, with the flock tracking SE-NW at an altitude of 1100ft on 1013hPa. Air system breaks off at 4.5 miles.

17:17

A second return shows high bird activity further up the cable and crossing the runway from SSE-NNW. Approximate height 600-1000ft.

17:19

Radar detects another large return just off the runway 23 threshold tracking E-W at approximately 600ft. Sierra at downwind leg of RTC.

17:23

Radar detects two large flocks over the intersection and north side of runway 23, tracking E-W and S-N between 550-1000ft. Sierra within 4 miles of runway and awaiting clearance. So, the supervisor instructs the controller to break off the approach.

17:30

Yet another flock is detected over the intersection. However, this one is stationary at an altitude of 300-800ft. This causes the contacts to merge and makes height visibility unclear. Sierra downwind of the RTC for a further ILS to land.

17:31

Sierra on final approach and awaiting clearance to land. The radar shows no large bird returns on or above the runway. One flock, tracking NE-SW, turns directly W after the aircraft has passed. Sierra lands safely.

Radar to the rescue

Thanks to the real-time data provided by MAX^®, controllers had advanced warning of potentially hazardous bird activity around runway 23. This enabled them to accurately monitor and track nearby flocks, aiding with the recovery and reducing risk.

Fast and accurate drone detection at one of Europe's busiest airports

One of the busiest airports in the world, Heathrow processes 70 million passengers every year and serves 203 destinations in 84 countries. The smallest disruption can bring commercial flights to a standstill. And, as demonstrated by the Gatwick drone incident of 2018, it’s the airlines that bear the brunt of the costs.

Heathrow deployed Robin’s counter-drone radar system in 2020 as a key part of the airport’s bespoke defense strategy. This has enabled security teams to detect rogue drones quickly and accurately, helping them protect passengers and keep delays to a minimum.

Improving flight safety with avian radar

The Royal Netherlands Air Force (RNLAF) is dedicated to improving flight safety. And enhancing bird detection across their airfields is a top priority.

Bird strikes can cause serious damage to military aircraft. This can lead to operational downtime, lost aircraft and, in the worst cases, fatalities. They introduced our 3D Flex and MAX^® radars across all six of their air bases as part of their bird radar project. The new systems have enabled the RNLAF to gather objective and persistent knowledge of bird movements around their national air bases – reducing bird strikes and increasing flight safety.

Real-time bird monitoring for Schiphol

Amsterdam Schiphol Airport is the Netherlands’ main airport and the third busiest in Europe. Due to its size, bird control teams struggle to monitor activity across the site. And this puts vulnerable species and valuable aircraft at risk. To tackle the problem, Schiphol deployed Robin’s 3D Flex radars.

Flex delivers actionable information on bird movements in a 10km radius around the airport. Real-time monitoring capabilities allow them to track high-risk species, while long-term data gathering and analysis provide crucial input for habitat management and mitigation strategies.

Robin Radar Systems has over 30 years of applied radar science. It started as ROBIN in the eighties, a project within the well-respected Dutch Research Institute for Applied Science (TNO). The project name was an acronym for Radar Observation of Bird INtensity.

The goal was to prevent collisions between birds and planes for the Royal Netherlands Air Force. In conjunction with the FlySafe initiative of the European Space Agency (ESA), TNO developed software algorithms to process raw radar images from air defence radars to visualize bird intensity. Since achieving commercial viability in 2010, we have provided detection solutions to airports, wind farms, and military installations around the world.

At Robin, we believe that knowledge is power. And a position of full situational awareness is the difference between being at risk and being in control of risk. Full situational awareness at any air base is game-changing in terms of reducing the operational downtime caused by bird strikes or a potential drone threat.

Our range of bird and drone radars track the exact flight paths of both flocks and individual birds up to 10 kilometres and drones up to 4 kilometres. They automatically detect and log hundreds of birds (and drone swarms) simultaneously, including their size, speed, direction, and flight path.

Radar tracks are displayed on intuitive interfaces to empower teams with unprecedented situational awareness. We know that detection is key, but only the first step in neutralizing a drone threat. That’s why we built our drone detection radars to integrate seamlessly with other technologies.

For more information about the MAX^® or any of our other solutions, get in touch today.