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, 71