Hi all,
Does anyone know how open sky above a cliff and trees would result in a poor GPS signal?
Having lost a second Neo I contacted DJI. They looked at the data and replaced 1 drone that span out of control after take off and flew out of range. Bonus, I didn’t expect it. It’s the first loss I have trouble with. Flying over the river in Chepstow at 120’ high the drone lost gps and went to ATTI mode. Chepstow has a castle and a liver. On the England side of the river there’s a small white chalk cliff with a few large houses on top. There are large trees atop the cliff. My drone lost GPS and drifted into the very tip of a tree. The drone dropped to 100’ (ATTI mode). It’s just odd to me it lost satellite coverage with no obstacles and clear open shy. There is a large metal bridge a few miles away but nothing in the sky. According to DJI “ GPS signals can be affected by ambient occlusion, which block or interference of satellite signals due to environmental factors. Even when the drone appears to be in open area, certain conditions may still result in weak GPS signals such as the follow:
While the tree may not have leaves, other surrounding foliage can still interfere with GPS signals by scattering or attenuating them. This can temporarily weaken the GPS signal.
For GPS to maintain accuracy, the drone must maintain a strong connection with multiple satellites. If the number of visible satellites is reduced due to the drone’s position relative to the terrain or obstacles, the GPS signal can become unreliable.
Factors like dense humidity, heavy clouds, or ionospheric disturbances can also weaken GPS signals, even in areas that seem clear.”
I really don’t know we’re to fly now. I took Neo 3 out today in Kelston (near Bath) again, clear open sky it lost GPS. I’ve never had this with my Hubsans, not even the Zino mini pro. I don’t fly any drones over 250gms now. Maybe the Neo is just too small?
We’re seeing more and more reports of the Neo dropping in to ATTI mode when being flown with some enthusiasm.
Bruce Xjet mentioned this exact issue just last week too.
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@Snothead have a read of this thread too: Neo Fly away
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That’s got to be an issue with the drone it’s self, I’ve flown around Chepstow plenty with both my mini 3 and air 3s and never had an issue, even flying under the old metal bridge and back up to over the castle I’ve never had satellite signal drop out
Remember there are currently certain world events occurring.
I had GPS problems with BOTH of my drones. Neither would get a signal indoors, and took ages to get a signal outdoors. A few days later, everything was back to normal. I also checked this with another portable GPS unit, and it too had problems.
I think it is safe to say that GPS is currently “unreliable” and could go out at any time. No, there is no requirement for GPS outage due to the military to be published, as it is war time, and not a test.
Commercial airlines are also experiencing GPS issues, to the extent that Airbus is currently developing procedures for its aircraft as they were not designed with regular spoofing/outages in mind. Quite the design flaw.
GPS is line-of-sight from the satellites, which is why the number of satellites available for use by your drone varies as they ‘appear’ and ‘dissappear’ over the horizon. The line of sight is of course mostly unobstructed for the bulk of the distance between the satelllites and your drone, but problems can and do occur when the LOS is broken for sufficient of the theoretically ‘available’ satellites. Atmospheric refraction and dense clouds can affect the signals, as can electromagnetic pulses, so solar storms & thunderstoms. Nearer the ground, hills, cliffs, buildings, and trees will have some effect as well.
I am interested in this because I intend to fly Chepstow castle and the cliffs in due course. The Wye valley at this location is in a deep gorge cut into the local limestone (not chalk, chalk is a type of limestone but not all limestone is chalk, not all fruits are oranges) with sheer cliffs on each side of the river. In such a location, a deeply-formed valley where the clifftops are at a steep angle from any observer’s postion on the valley floor, a number of predicted GPS satellites will not be ‘visible’, and as they are in circumpolar orbits (flying between poles and not around the equator like tv satellites) this will be most prominent from the easterly or westerly directions, precisely the alignmnet of the river and the gorge for much of this section of the valley!
Most drones will cope, but as there seems to be a question mark over the Neo’s resilience to such problems, it might be that the location has caused this particulare model problems when other types would fly normally. Neo owners will need a degree of senitivity and understanding of the issues possibly caused by local landforms and alignments, and be aware of potential problems.
And they are mostly potential as opposed to definitely real problems. There are all sorts of things that will stop you flying your drone; solar storms, birds, humidity, high temperature, low temperature; best is to be fully aware of them and that they might prevent you from doing what you want that particular day, but the more you fly your drone the better you will become at it, and your increased confidence will enable you make rational risk-assessment decisions. In ‘real’ flying, pilots log their hours in the air, for good reason; the same reasoning applies to us.
Thanks, I thought as much. I’ve flown many drones in the same area with no issues. I did take Neo number 3 out over Kelston (Bath) yesterday. It lost GOS twice. Open sky low wind and @250’ so no trees. My Gubsan drone went up straight after. It always had a minimum of 14 satellites. I suppose the Neo is very cheap. I only paid £119 for the last one at Argos so almost a throw away. I am still concerned it can damage something or someone though.
Interestingly I did ask Ofcom if there’s any spurious signals in the area (already checked mil establishments). Apparently 2.4 and 5g are unregulated, so it’s perfectly legal to use a jammer to stop Wi-Fi. I had thought that to be illegal. There are a couple of very large houses above that rock face, so maybe they have some very high power Wi-Fi? I have a 6 node mesh system at home, it doesn’t Dave ant affect on my other drones, But am wondering now if it caused the second fly away. I hovered Neo no 2 in my garden. It moved around at the time and I assumed it was because I launched from the lid of a hot tub. It’s black vinyl so no contrast it does have a wifi connection so I always turn it off when not in use these days. My drone went mad above the rock amongst the trees. My plan being to pull back about 20 feet and drop down to film “the English hole”. The drone lost connection and drifted into the only twig at the top of the tree. Video feed was never bad. The drone sat in leaves at the top of the rock face. Didn’t think it same to try and recover.
MMM I wonder if the NEO has a GPS issue as today I went up to the Peak district near Snake Pass and launched the NEO using the phone app only and it went crazy and did what I would basically call a flyaway as I had little to no control of it. Lucky I was able to ditch it into the snow before it went off too far away.
I then tried it with the RC controller and it was just as bad even though I got the Home Point updated before I tired to fly anywhere with it and it also behaved erratic for what ever reason.
The condistions were really good other than snow on the ground and a very light fog in the air but it was easy enough to see the drone 30+ meters away for sure -
Air Data attached —
Using Phone only as a controller —> 12-01-2025 11:08:35 | General / Overview | DJI Fly log 1.15.8 | United Kingdom | Airdata UAV
Using the RC-N3 controller ----> 12-01-2025 11:16:33 | General / Overview | DJI Fly log 1.15.8 | United Kingdom | Airdata UAV
Using the phone controller I see it reported high winds - very much not the case - it was just about perfect outside other than the cold.
MMM wonder if I need to send it back as something seems to be off here.
Wonder if the NEO has bad firmware currently. Thats 3 issues just on this forum.
Carver messing with the timings again, time to get Pierce Brosnan out of retirement.
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Raise a ticket with DJI you had 20 sats on the first and 29 on the second, no reason to go into Atti mode
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Whats interesting is that both occurances happened at 1m19s 
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I did think that the higher the number the better or more sats you were connected too but then seeing that it then said no gps made me think I had it wrong
Thanks for the clarification
Also good spot on the time too
Will rise a ticket with DJI and question it with them.
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If the problem arises consistently at 1minute 19seconds, it could be that something is overheating. In any case, with the data showing good satellite availability and no reason for the drone to switch itself to ATTI, it’s definitely a return to DJI job. They usually replace faulty drones rather than repairing them, which is great but will not make you any more aware of what the cause of the problem is.
They may be unable to locate the fault of course; mystery faults are rare but they do happen! Back in the 70s, had a brand new Honda CG125 motorbike, which cut out at exactly the same place every time I rode it, and after the 3rd time of pushing it to the dealer they admitted they could fine nothing wrong with it and suspected a wiring loop fault. This did not cure the problem, so they eventually offered me a replacement new bike, despite not being able to say what was wrong with the old one! I’d had enough by then and put extra money to a brand new Kawasaki Z200, which I had for 8 years and never gave me any bother in the slightest! Guy in the showroom said it wasn’t worth wasting time investigating the 125, and they’d scrap it for spares. virtually brand new…
Found something else in the logs, the GPS Level drops to zero
Following enum class represents GPS signal levels, which are used to measure the signal quality.
DJIGPSSignalStatus
Level0 The GPS has almost no signal, which is very bad.
Level1 The GPS signal is very weak.
Level2 The GPS signal is weak.
Level3 The GPS signal is good.
Level4 The GPS signal is very good.
Level5 The GPS signal is very strong.
None There is no GPS signal.
DJI translates that into:
Level0: The GPS has almost no signal, which is very bad.
Level1: The GPS signal is very weak.
Level2: The GPS signal is weak. At this level, the aircraft’s go home functionality will still work.
Level3: The GPS signal is good. At this level, the aircraft can hover in the air.
Level4: The GPS signal is very good. At this level, the aircraft can record the home point.
Level5: The GPS signal is very strong.
None: There is no GPS signal.
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Same issue on the other flight
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