Global Security and Intelligence Studies Volume 2, Issue 1, Fall 2016 | Page 78

Global Security and Intelligence Studies due to increased ambient noise, it was implemented at the 2015 Boston Marathon and it can protect mobile targets, as the tool is available for vehicles, such as a VIP convoy (Abbott et al. 2016, 17; Sathyamoorthy 2015, 88). Unlike some visible defense mechanisms, it is unlikely a lone wolf would detect or become aware of acoustic sensors near a target prior to the attack. One significant challenge with this technology is the internal sound database, which will require updates as companies manufacture new drone models. Nonetheless, the DroneShield’s ability to identify specific drone models may cue security forces to recurring instances of a unique drone flying nearby, possibly probing the perimeter and testing security responses or conducting reconnaissance for a future attack. Radar Radar is one of the most effective methods to detect and track aerial threats, but this defense mechanism encounters unique challenges when applied to consumer drones. Air surveillance radar in the United States is ineffective against consumer drones, as these systems detect and track, but do not interdict, planes moving at high speeds, as opposed to smaller drones moving at relatively slow speeds (Sathyamoorthy 2015, 88). Installation and maintenance of radar systems can be very costly, explaining their limited presence in the United States. Some sophisticated radar systems “can see something as small as a bird flying,” presenting false positives or distinguishing small drones from birds using precision radar and analytics (Elias 2016, 20; Maddox and Stuckenberg 2015). Such systems can provide early warning to long-term static targets, especially with physical standoff in the form of clearings between a facility and its perimeter fence, but a cost–benefit analysis yields poor results in defending temporary static or mobile targets. Furthermore, drone operators may fly at low altitudes, below 100 ft, to capitalize on inter-visibility lines created by surrounding terrain to block line-of-sight required for radar detection (Elias 2016, 20). Radar systems are not the most feasible or easily implemented methods to defend against lone wolves operating an explosive-laden drone, providing a false sense of security for sites protected by a dense array of radar systems. The Human Eye The naked eye remains the most reliable and practical defense against an explosive-laden drone. Ironically, no technical asset detected or brought down the consumer drone that landed on the White House lawn; instead, “a Secret Service officer standing guard” spotted the drone (Leonnig and Whitlock 2015). A combination of human senses provide a redundant means to identify and locate drones, such as seeing a drone’s shadow on the ground or hearing a drone overhead. In Iraq, where radars “intentionally eliminate slow-flying targets on or near the ground” to prevent overtaxing tracking systems, human eyes are also “the most effective means of detecting such slow-flying threats,” such as consumer drones (Gormley 2003, 8–9). Proving to 72