How do Drone RF Jammers work?
There are a number of technologies under development to prevent dangerous drones from entering no-fly zones or causing harm to civilians. Among these, radio frequency interference (RF) or drone jammer can be used to jam the drone's RF signal, causing it to drop out.
An RF jammer is designed to interfere with a UAS or drone by triggering electromagnetic noise in the RF that is used by drones to operate and transmit video at a level high enough for effective communication between the systems and disturb his pilot.
Generally, this RF interference is either 2.4 GHz or 5.8 GHz, which are unassigned public frequencies. When using these frequencies, the jammers do not interfere with manned aircraft, cellular communications, public broadcasts, or other dedicated radio bands.
Jammers act against drones over a distance of several kilometers. Most RF jammers operate with a ratio of the distance between a drone and the jammer compared to the drone with its pilot. In general, the further the drone is from the pilot and closer to the jammer, the better. A typical effective jammer direction is a cone of about 15-30 degrees protruding forward from the gun (this is also affected by the RF band and jammer performance).
In addition to RF interference, GPS interference can also be used as a large number of drones rely on GPS to either counterbalance headwind or to navigate between designated points.
If a drone is intercepted by an RF jammer, the system will usually revert to its point of origin (unless the GPS is also jammed), giving the user the ability to track the drone.
Alternatively, a jammed drone can even perform a vertical descent and land in place, offering the opportunity to conduct a forensic investigation.
The limitations of RF jammers to combat fraudulent drone threats.
In the most recent test scenarios, however, several analysts agree that signal interference as a countermeasure often does more harm than good. For example, in December 2019, in an incident at Gatwick International Airport in London, two rogue drones flew within the airport's restricted airspace. Gatwick officials reportedly tried various methods of remedial action, including interfering with the drone's RF signals, which proved ineffective.
1. Lack of precision
The level of precision required to accurately jam the drone signal without jamming other signals based on the same radio band is technically difficult to achieve.
The person interfering with the RF signal must point the jammer at the moving target and consider several variables - from speed and velocity to distance, direction, angle of arrival, and altitude - while making sure they are not on or nearby showing objects This could be negatively affected by interference from RF signals in the vicinity.
Criminal or terrorist-operated drones can be purposely flown on a GPS waypoint, completely eliminating the RF signal.
2. Risks of collateral damage
The operator has to guess which RD tape the signal is running on. The typical range of 2.4 to 5.0 GHz means that any system operating in this range can also be disturbed.
This can potentially be disastrous. For example, air traffic controllers use radio to communicate between the pilot and the tower. A congested signal can potentially interfere with this communication.
An interrupted signal can interrupt communication between these critical processes and lead to a disaster in air and ground traffic. Airport commuters and guests using Wi-Fi can also interfere with their signal, causing enormous inconvenience.
