> Sudden GPS errors can also result from the anomalies.
When we fly drones especially BVLOS operations we sometimes encounter some GNSS anomalies, that in some cases we just cancel the mission that day and the next day it’s with no issues. Could it be that’s the reason? Who knows, but it might be an issue later with crewed drones.
That depends of what exactly is that anomaly. If your GNSS receiver tracks 4 satellites from the same constellation then obviously, this kind of ionosphere anomaly will with some probability lead to some kind of unexpected fix error (but with some high probability still smaller than the specified error of such receiver). I believe that typical somewhat modern multi-constellation GNSS receiver will either consider satellites affected by that as invalid outliers or just average that out.
Usually when they carry passengers but with no pilot/s, they get called crewed (or manned) ones, but to be honest, there’s no definitive answer or definition as there’s always a mix, sometimes it’s called unmanned/manned aircraft, unmanned/manned drone, uncrewed/crewed drone, and in Canada they even created their own terminology, RPAS (remotely piloted aircraft system), so take the whole thing with a little grain of salt :)
If you have a dual frequency receiver (L1/L2), then the ionospheric error is corrected for. These are very common these days, so probably not the reason.
We had similar anomalies with tri-bands gnss drone before (L1, L2, and L5) with multi constellations support, I even remember before we had similar issues with an RTK enabled system.
It is puzzling because the next day we would bring the sane drone and systems, and as of nothing happened, and since the problem solve itself we never bothered to investigate more.
If it's obvious a spectrum analyzer will help, but GPS signals are very weak and you won't be able to see anything without special equipment. (-125 dBm at the Earth's surface; that's ATTOwatts of power.)
When we fly drones especially BVLOS operations we sometimes encounter some GNSS anomalies, that in some cases we just cancel the mission that day and the next day it’s with no issues. Could it be that’s the reason? Who knows, but it might be an issue later with crewed drones.