To form the sparse array antenna, the robots arrange themselves at roughly equal intervals

Wednesday, May 8th, 2024

Swarm Troopers by David HamblingSeveral drones working together can act as a single large radar dish, David Hambling explains (in Swarm Troopers), an arrangement known as a “sparse antenna array”:

The emissions from several drones are combined together into a single signal in a process called beamforming.


To form the sparse array antenna, the robots arrange themselves at roughly equal intervals, generally in a line or a circle. One robot acts as master and has software that takes information about the signal at each of the antennas — specifically the amplitude, phase, and delay — and combines this information to get an enhanced signal. There is little extra hardware needed as the system exists almost entirely in software, so any of the drones can be the master.


In a process known as nulling, the jammer signal is detected and located from its influence at different points, then completely cancelled out.

“I showed that we could completely ignore the effect of a jammer, positioned between the transmitter and receiver, that was twenty-three decibels above the desired transmitted signal,” says Okamoto.

Twenty-three decibels means the jammer is transmitting noise two hundred times as powerful as the source signal. It is like being able to hear a distant whisper while someone is bellowing in your ear.


In addition, Kocaman’s paper demonstrates how ten drones could act together and use “distributed beamforming,” like Kitts’ formation robots, to achieve more than a simple addition of their power would suggest. Kocaman calculates ten of these drones could jam a Russian Sam-2 Fan Song anti-aircraft radar, producing too much radio noise for the radar to “burn through.” This would render it helpless – the drones could broadcast the radar’s exact location with impunity, and even “lase” it with a designator, making the radar a sitting duck for an air strike.


A swarm that combined jammers with “flying IED” would be able to overwhelm a ship comparatively easily. If it attacked at night, even the last-ditch machine-guns would be lucky to score any hits.


Its ability to act as a giant antenna means it could carry out stealthy electronic eavesdropping over a wide area.

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