Over the last two years, the Anti Drone systems have attracted a lot of attention, with the advent of SWARM attack threats, there hardly a few in the security detail, who might have not heard about this new setup.
Popularly known as cUAS, the Counter measures to monitor and mitigate the hostile drone threats are an enigma of sorts, each one trying to defend with one solution or another with a sole objective to stop the intruder in its tracks and prevent it from causing any harm.
The most important aspect of the Anti Drone solution is Detection, the specialised sensor stack, which provides an alert if any new flying object enters the monitored airspace, easier said than done; till the time the drones are broadcasting their identification dataset, it is easier, it all depends on the configuration and sensitivity of the radios deployed.
While the most of the popular models like DJI can be easily detected, identified and to some extent, even tracked, the bit difficult part is to find the drones which do not transmit their Drone ID, the ones which have been tampered with or even more deadly, DIY types fabricated by the guys with nefarious intent.
To detect these dark drones or RF Silent drones, Radars and EO devices are common, sometimes assisted by an elaborate array of accoustic sensors, however, the problem lies with the ease of operations, none of the latter are as modular as the most popular device called Aeroscope, earlier sold by DJI for the benefit of the Airspace regulators, now kind of discontinued after its widespread use in the Ukraine- Russia conflict. Some of the NextGen RF sensors are able to detect the frequency hopping signals used by the drones and even geolocate those in 2D and 3D, but those kind of SDRs are both expensive and require careful calibration and training.
EO devices or Day & Night PTZ cameras are good for fixed sites, where a perched up installation is possible, however, these need a clear line of sight, sometimes not quite feasible in dense Urban environment or in mobile applications. Night vision thermal cameras come with a steep price tag and other limitations and hence generally conspicuous by their absence in field conditions.
Radars are becoming the first choice for detection as these can work Day & Night and do not generally get affected by climate, thus the sturdy ones can be left out to provide 24×7 situational awareness. Radars also require an elevated mounting position to be able to see the distance and avoid the ground clutter. Legacy perimeter surveillance radars weren’t designed to detect drones or birds, but much larger objects like vehicles, human and animal intrusions, their Air Defence counterparts can detect even a small aircraft nearly a hundred miles away, but they can stare at drones inconsequently just because those small objects can not trigger any response.
Moreover, the Radars are generally not designed to look at the ground as the reflections from the ground will provide a humongous amount of data to be processed and overwhelm the Radar, thus the drones can fly undetected under the Radar. Only a few AESA panels with STAP capabilities can detect the drones flying under the installation height of the Radars
Acoustic sensors were earlier not quite popular, however these are making a come back as these are low cost as compared to Thermal cameras and Radars. Acoustic panels can be deployed in remote Rural or forest conditions as the urban noise can create an issue.
You cannot fight an enemy that you cannot see and thus most of the generic cUAS or Anti-Drone systems seemingly fail to stop the FPV attacks.