Small UAVs, Big Challenges

Russian-Drone-Shot-Down-Ukrainian
A Ukrainian soldier stands by the wreckage of a destroyed Russian UAV. Electronic warfare has a valuable role to play on the battlefield engaging such threats alongside kinetic fires.

IQPC’s Full Spectrum Air Defence conference, held in London on 28th and 29th June, saw valuable discussion on the role of electronic warfare within the wider air defence domain.

The ongoing war in Ukraine was very much on delegates’ minds. A prevailing theme was the increasing complexity of the air environment and implications therein for air defenders. This deepening complexity is hallmarked by emerging capabilities like weaponised Uninhabited Air Vehicles (UAVs).

Small UAVs pose unique challenges for air defenders. They have a low Radar Cross Section (RCS) of circa 0.05 square metres according to figures in the public domain. To put matters into perspective, a mortar shell has an RCS of 0.01 square metres. The small size of these small UAVs makes them difficult to detect and engage.

Electronic Warfare (EW) plays an important role in the Counter-UAV (CUAV) battle. UAVs rely on Radio Frequency (RF) links connecting the aircraft to its Ground Control Station (GCS). In the civilian domain, these links use frequencies of 2.4 gigahertz/GHz and 5.8GHz. They send and receive flight information and commands between the UAV and GCS and may also carry imagery from the UAV to the GCS.

Alongside this link, UAVs rely on Global Navigation Satellite Signals (GNSS). GNSS uses frequencies of between 1.1GHz and 1.6GHz. Both the GNSS signals and the RF link can be disrupted through electronic attack. This can break both links causing the UAV to return to its launch site, land harmlessly or crash. Usefully, detecting the RF link can reveal where the UAV and GCS are located. This is invaluable for engaging either the UAV and/or the GCS.

US Army

Speakers from the US Army said the force has several EW capabilities which intercept and manipulate protocols and waveforms used by the UAV-GCS RF links. This lets air defenders take control of the UAV and take it out of the fight. These same systems can jam the link or disrupt GNSS signals.

While the majority of CUAV interceptions performed by the US Army in wartime have been kinetic, EW has a role. EW is useful when fratricide and collateral damage is a worry and when the use of kinetics could be risky. For this reason, electronic warfare is vital to the army’s CUAV force balance.

To this end, emerging capabilities like the US Army’s Tactical Electronic Warfare System family of products have utility. EW also has a role supporting the wider ground-based air defence battle, US Army speakers continued. This involves using EW to attack the radar and radio communications airpower depends on. Electronic and communications intelligence can be employed to help detect and locate hostile aircraft. This helps populate the recognised air picture when shared with air defenders in a rapid and cybersecure fashion.

Tactical Considerations

However, use of EW as a CUAV capability triggers concerns over electromagnetic fratricide. Questions were asked on the use of electronic effects against UAVs while ensuring unimpeded blue force use of the electromagnetic spectrum. Troops at the tactical edge will send a ‘check fire’ message if artillery is falling too close to their positions, but having this message blocked by blue force jamming could have disastrous results. US Army speakers argued there is no silver bullet to address this quandary. Instead, they emphasised the need to integrate kinetic and electronic effects, including cyber effects. These must be integrated in planning and targeting processes at the operational and tactical levels as early as possible.

At the tactical level, one speaker remarked that electronic attack is useful in forcing a UAV to hover making it an easier target for kinetic effects. After all, it is much easier to hit a stationary target than a moving one especially when that target is small.

Outlook

That electronic warfare has a useful role to play in assisting the counter-UAV fight is not in doubt. Nonetheless,  it must be used judiciously in a well-coordinated manner alongside kinetic effects. Future ground-based air defence conferences will no doubt discuss such questions in more detail.

by Dr. Thomas Withington

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Editor, Defence commentator, journalist, military historian.