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Comment by naz | Hacker News Reader

It's surprising that GPS signals are that important to these displays. I figured they use GPS to provide a rough center of the display, for the "leader" drone, and the other drones would position themselves relative to their leader using some local peer-to-peer positioning signals.

Then again, I know nothing about this.

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Drones like this use DGPS. GPS is inherently inaccurate when you need centimeter level precision, especially with spinny bladed machines in formation. DGPS uses a ground station that helps the drones gain the accuracy they need, but it's much more complex than a simple GPS unit.

I suspect the specific implementation here uses "carrier-phase RTK" which means the recievers are locking into the pure sinusoid of the carrier frequency to get sub-centimeter positioning accuracy. It's mind blowing that this works at all, given that it really isn't how the GPS system was designed to be used.

Surely drones do not need DGPS unless they need precise location against the ground.

For swarms, drones need precise location relative to each other, for which there are other techniques than GPS.

I think you are speculating - or do you have information showing that these drones use DGPS for this display?

GPS + accelerometers in fusion are accurate enough, and what you describe AFAIK doesn't exist in off-the-shelf variant, which is usually the core consideration.

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