Airport Drone Mitigation
Part 1: What is Jamming and How does it Work?

November 15, 2022 | Mark Rutherford

In my previous blog – Why Mitigating the Increase in Rogue Drone Activity in the Vicinity of Airports Has Been Such a Hard Nut to Crack – Until Now? – we looked at the proliferation of drones and why they’re fast becoming a real nuisance to airports and air travel. Using the “VULNERABILITY x THREAT = RISK” model, we were able to establish that drones were not only a ‘Security’ risk, but also a major ‘Flight Safety’ risk too. While we know they pose a credible THREAT to airports and aircrafts in flight, the RISK is real, due to VULNERABILITY. Until the advent of new generation C-UAS technologies such as RF cyber-takeover as represented in D-Fend’s EnforceAir, the only options available to airports were jammers or other effectors, which capture or kill the drone. These were dismissed as unsuitable for airports due to several factors, which I’ll present to you in a new series of airport-related blog posts.

In this first piece, we’ll start with jammers, a security equipment claimed to be effective against drones. In the upcoming posts, we’ll dig a little deeper and look under the bonnet (hood!), before analysing and comparing them to an effective cyber-C-UAS solution.

Update on ‘Near Misses’ with Drones in Controlled Airspace

In my last blog, I made a statement that drone incidents in controlled airspace were on the increase. I don’t have a crystal ball, but the data we looked at indicated they would continue to persist. But did they?

The short answer? Yes.

As we posted in the D-Fend Solutions’ Drone Incident Tracker,  there were more than 70 additional incidents reported in the public domain since my last blog (many of those in the airport space)  of which more than 20 were extremely serious. In one, a Delta Airlines pilot reported that a drone narrowly missed the windshield by 8 feet at the Orlando International Airport!

So, what is Jamming?

‘Interference’ is the unintended disruption of wireless communications, whereas ‘jamming’ describes the deliberate act of interfering with the purpose of blocking communications. In lay terms, it means directing a very strong signal at a drone, blocking out the drone pilot’s signal commands so they can no longer control it and/or the GPS signal. Technically speaking, it’s much more complex than that and, to understand why it’s not suited to airports, we need to know how jamming and jammers operate.

How Do Jammers Operate?

There are two types of jamming: repeater jamming and noise jamming. The most common form of repeater jamming is digital frequency radio memory (DFRM). However, I’ll not cover it in this blog as it’s not applicable to drones, unlike noise jamming which is used against drones.

When it comes to drones, noise jamming is the main type of jamming. It involves three main techniques:

  • Spot Jamming – The jammer transmits all its radio frequency (RF) power on a single frequency – the one the drone is on. The issue with spot jamming is that it can’t deal with drones which are frequency agile as they use more than one frequency.
  • Sweep Jamming – The jammer shifts all its power from one frequency to another, sweeping up and down multiple frequencies in quick succession – although not all at the same time. Sweep jamming these multiple frequencies may result in , as the jamming could affect airport systems, which may malfunction or have to be switched off to protect them from the jammer’s high-power transmission.
  • Barrage Jamming – The jamming of multiple frequencies all at the same time using a single jammer. As we saw with sweep jamming, pumping out RF power to multiple frequencies may have an impact on airport operations. Not only that: with barrage jamming we have a power problem – the jammer spreads its power across multiple frequencies, making it less powerful on any one single frequency and decreasing its effective range.

As you can see, pumping out massive amounts of energy may have an adverse effect on airport systems…

In the next blog post – The Issues with Jamming Drone Frequencies – we’ll look at the problems with jamming frequencies and its effects.

Mark brings a vast amount of business and operational expertise, focusing on engaging with airports, critical national infrastructure, and those owning or managing estates and facilities, where the threat from drones/UAS poses a real risk. Mark delivers high quality and reliability to D-Fend’s customers and partners, educating the market about the need for the most advanced solution for safer airspace.

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