Global Security and Intelligence Studies Volume 2, Issue 1, Fall 2016 | Page 77
An Assessment of Lone Wolves Using Explosive-Laden Consumer Drones in the United States
Current payload limitations severely restrict the amount of potential damage
resulting from an explosive-laden consumer drone flying into a building, specialized
facility or crowd, but payload capacities will likely increase in the future. Existing
drone models can feasibly carry the sufficient amount of explosives to assassinate an
individual, injure dozens in a dense crowd, trigger a larger explosion at a chemical
facility or cause minor damage to buildings, depending on the proximity of the blast.
The government has not established constraints for payload weight, so that capacity
will likely increase over time as companies manufacture larger and more robust drones.
The prospect of heavier payloads seems more realistic as companies like Amazon
experiment with drones to deliver packages.
Evaluation of Defense Mechanisms
Similar to the defense-in-depth concept for physical security practiced by
government agencies and corporations, a series of defense mechanisms improves
the odds of detection and interdiction. Many technical assets can defend long-term
static targets, but it is unfeasible to implement such costly defense mechanisms for
temporary static targets or mobile targets. Unfortunately, “drones can easily bypass
many of the security measures implemented since 9/11,” including many sophisticated
defense assets, yet some can potentially mitigate the likelihood or severity of a drone
attack (Maddox and Stuckenberg 2015). The most viable detection methods include
acoustic sensing, radar and the human eye, while the most efficient interdiction
methods are geofencing and kinetic defense. Additional interdiction methods include
command link jamming and global navigation satellite system (GNSS) jamming, but
these are less feasible options as “jamming the radio signal of a drone (or cellphone or
anything else) is illegal in the United States under long-standing federal law,” because it
may interfere with emergency services (Ripley 2015, 70). These countermeasures must
continue to evolve as consumer drone features improve and become more effective in
overcoming and bypassing existing security measures.
Acoustic Sensing
Consumer drone models produce distinct noises difficult to replicate. Acoustic
sensors can detect nearby drones by these unique sound signatures generated by
drone motors (Sathyamoorthy 2015, 88). One such sensor, called a DroneShield, can
quickly detect a drone by model and send out a text-message alert to nearby guards for
monitoring and interdiction (Ripley 2015, 67). Although the tool is passive and only
serves to detect when a drone flies nearby, the automated text mechanism increases
the chances of interdiction by alerting guards who can shoot down the drone. The
DroneShield is equipped with a database of “common UAV acoustic signatures,”
reducing the chance for false alarms and increasing precision detection rates
(Sathyamoorthy 2015, 88). This detection mechanism is more affordable than most and
is easily installed and transportable. While the DroneShield may be most effective in
defending long-term static targets and less so defending some temporary static targets,
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