Drone incidents have become a well-documented nuisance and credible threat to aviation. The lack of countermeasure equipment available to properly detect and mitigate drones while preserving the continuity of airport operations is resulting in a risk to both security and flight safety.
While there are many counter-drone (C-UAS) technologies available today, most of them originated in the military sphere. This makes them unsuitable for civilian airport environments due to their potential for significant adverse effects on airport operations.
More specifically, systems based on jamming can be very effective to stop a drone in a remote rural location. However, they can be highly problematic in a busy, urban civilian airport. Jamming can also impact airport operations for extended periods of time, which is obviously unacceptable in the context of time-critical airport schedules.
While ‘interference’ is the unintended disruption of wireless communications, ‘jamming’ describes the deliberate act of interfering with the purpose of blocking communications. In other words, it directs a very strong signal at a drone that blocks out the GPS signal and/or the drone pilot’s signal commands so they no longer have control.
There are two types of jamming: repeater jamming, which is not applicable to drones; and noise jamming, which is the main type of jamming against drones. Noise jamming involves three main techniques:
· Spot Jamming – The jammer transmits all its radio frequency (RF) power on the single frequency that the drone is operating on. The issue with spot jamming is that it cannot deal with drones that are ‘frequency agile’ due to their ability to operate on more than one frequency.
· Sweep Jamming – The jammer shifts all power from one frequency to another. It sweeps up and down multiple frequencies in quick succession, but not all at the same time. Sweep jamming multiple frequencies can result in airport operations being adversely affected, as the jamming may impact the airport’s communications or operational systems.
· Barrage Jamming – The jamming of multiple frequencies, all at the same time, using a single jammer. Just as sweep jamming may have an impact on airplane operations, so does barrage jamming. It also has a decreased effective range and is less powerful due to the jammer’s power being spread across multiple frequencies.
Commercial drones operate on four frequency bands: 2.4Ghz, 5.8GHz, 433MHz, and 915MHz. These frequencies are also used for other activities such as amateur radio operations, remote controls, vehicle keyless entry devices, door, gate and garage openers, radar frequency for aviation and maritime, radar systems, CCTV, weather, military, and amateur-satellite radars, and more. Given this, jamming any or all of these four frequencies could have an incredibly detrimental effect on airport operations and could even lead to major collateral impact on businesses and homes surrounding the airport. Jamming also does not have the ability to take over control of the drone – it only temporarily negates the control of the pilot. A drone that loses its remote controller’s signal will commence an “emergency default back-up plan,” which, in most cases, means it will either return home, hover in place, or land on the spot. If the drone pilot loses control and the jammer does not control the drone, the result is a drone that is controlled by nobody and acts the way it was programmed to, which in some cases is unknown to the jammer operator. This, in turn, may pose a risk to air traffic or ground operations due to a lack of control, even if the pilot did not mean to cause any damage and was going to withdraw from the protected area.
Overall, jamming's lack of efficacy and the potential harm it could have on busy airports make it an undesirable option to overcome rogue drones. So, what is the best solution? The only way to truly manage rogue drones is through complete control, and cyber technology is the key to achieving this.
Cyber technology is the next generation of C-UAS solutions. A proper RF cyber-based C-UAS technology can detect, track, identify and mitigate unauthorized drones, without affecting the surrounding airfield and airplanes. Such a solution could passively detect the drone’s RF signal, interpret it, identify if the drone type is authorized or not, and pinpoint the drone and pilot location. Once a drone is recognized as non-authorized, the RF cyber-based C-UAS technology would actively command the rogue drone to disconnect from the original pilot and then take complete control of the drone. Compared to jamming, this type of complete control not only puts the drone into a hover mode to prevent it from crashing into anything, it also automatically reroutes the drone along a safe corridor and at a safe altitude to a safe landing point of choice. With rogue drones under control, airport operations can continue safely and securely. It allows for a safer and more controlled outcome without compromise, negative fallout, or financial impact.
