Before evaluating or purchasing drone detection technology, it’s important to define needs. Different facilities face different risks, and a single facility’s risk can change with as little as an inmate population change.
Drone detection sensor type and configuration depends in large part on the risk assessment for each facility but let’s face it, budget is always a challenge.
For example, super-max facilities housing the most violent offenders present a different, much higher risk profile related to drone-borne contraband deliveries than low, medium or juvenile facilities.
Because of the super-max facility’s heightened security concerns, they may determine they need a permanently installed full coverage, radio frequency, radar with integrated pan-tilt-zoom camera multi-layer deployment that extends pretty far beyond the prison grounds.
Lower level facilities may only need airspace awareness and a proximity alert that a drone has crossed the boundary into the facility.
The drone contraband risk profile for a low or medium housing facility can vary by the inmate population itself which can change quickly when a high-level gang member transfers into a facility. A low-medium facility’s need may switch from simple airspace awareness when a drone crosses the facility boundary to the need to detect and locate multiple drones and pilots.
The Federal Aviation Administration (FAA) divides the four (4) drone detection sensor types into two (2) categories: Primary and Secondary.
According to the FAA, “Primary detection sources are those sensors that have a greater level of system autonomy, providing alerts to be generated upon a detection, prompting further investigation by the detection system operator.”
In other words, primary sensors are able to detect drones with high enough accuracy and low enough false alarm rates to operate as standalone solutions. That is, they do not require data from other sensor types in order to validate their detections.
Secondary sensors need additional data from other sensor types in order to accurately detect drone threats. These additional sensor types can be used to enhance the accuracy of – or provide more detail about – drone threats, but they should not be used as a standalone system.
Sensor Type | Pros | Cons |
Camera/IR (Secondary) |
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Acoustic (Secondary) |
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Radar (Primary) |
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RF (Primary) |
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Because drones are so difficult to see, most cameras have a fairly short range of under 300 meters and require some primary alert system to notify the operator of drone presence.
Cameras coupled with Artificial Intelligence to detect drones work well on a blue-sky clear background. Once the drone moves to a cluttered background such as trees or buildings, the systems struggle substantially.
Weather and lighting conditions can adversely affect camera operations. Once the sun goes down, infrared camera capability would be required to see anything typically outside a prison boundary. Inside, of course, it’s still bright enough to see day or night.
Since most existing camera networks are pointed to the ground, they will not be very helpful to see drones in the air and should not be used as a standalone drone detection system.
One way to leverage existing camera networks to get eyes on the pilot is for an RF or radar drone detection sensor to automatically tell a Pan, Tilt, and Zoom (PTZ) camera where to point to see both the drone and the pilot either in real-time or video review.
Trains, buses, jack-hammers and everything in between generate noise that hides drone sounds. Even in quiet areas the acoustic detection range is very short, so the technology does not seem feasible for drone detection at a corrections facility.
Radar detects non-RF drones. While the vast majority of drones on the market use RF, some drones can operate without RF communication, and well-informed contraband delivery operators may use shields to attempt to mask the RF signals.
Radar detection is a transmitting technology so facilities must ensure the radars will not interfere with any other equipment. The facility must apply for the proper authorizations to deploy transmitting radar technology.
Radar requires line of sight which can make sensor placement at a corrections facility a challenge.
Birds, plastic bags and even wind that makes tree branches move and flags fly briskly can be a source for radar false alarms.
When radar and RF are combined, they can complement each other. Radar can detect non-RF drones and the RF system can detect and locate the pilot and drones potentially before take-off. Each system can validate the other’s detections to reduce false positives.
RF sensors emerged as the leading drone detection technology because they are the only type that reliably detects both the controller and drone, require little maintenance and operate in all weather conditions.
Since RF-based systems operate in different ways, there are several important considerations to determine which system will be the best fit for your facility. Here are a few key questions to help you evaluate:
Drone and Controller Detection Information
Alerts
Deployment
Legality
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