Is there a way to boost GPS signal?

[Nonprophet]

Tried flying around a couple of my favorite local Oregon waterfalls this weekend--but couldn't get a good GPS fix. At one location I got 8 satellites, but I've heard horror stories about flyways when the GPS signal started at 7 or 8 and the pilot hoped the signal would get stronger once airborne, but GPS signal was lost and the drones flew away....

So I've seen people put Go-Pros on top of their Mavic series drones and certainly an add-on GPS receiver would be smaller than that, is this doable? Do the more expensive drones have better GPS receivers? BTW, I had my Garmin Inreach Explorer+ with me at all the waterfall locations and it of course had a strong signal.....

 

[lannes]

I suspect the AC would have been in a GPS shadow caused by the waterfall rock face, you might need to fly from above the falls with a downward view if you still want a strong gps connection.

You were probably standing further away from the falls with the Inreach Explorer, but the AC might have been much closer and in the GPS shadow.
I believe for a location lock you need 4 satellites while the MA2 will need about 8 for flight, this is why you might be seeing a difference in the signal strength indicators.

Along with many other factors , the GPS signal is also affected by the time of the day the satellites are tracking overhead and the number of them nearby.
Maybe look at using UAV forecast, which will give you a estimate of satellite lock for a particular location at a particular time, to figure out the optimum time to visit your locations.

UAV Forecast

UAV Forecast combines weather forecasts, visible GPS satellites, and solar flare (Kp) activity, to produce a comprehensive report and forecast of flying conditions for Unmanned Aerial Vehicles.

www.uavforecast.com

 

[dawgpilot]

Tried flying around a couple of my favorite local Oregon waterfalls this weekend--but couldn't get a good GPS fix. At one location I got 8 satellites, but I've heard horror stories about flyways when the GPs signal started at 7 or 8 and the pilot hoped the signal would get stronger once airborne, but GPS signal was lost and the drones flew away....

So I've seen people put Go-Pros on top of their Mavic series drones and certainly am add-on GPS receiver would be smaller than that, is this doable? Do the more expensive drones have better GPS receivers? BTW, I had my Garmin Inreach Explorer+ with me at all the waterfall locations and it of course had a strong signal.....

Quick answer is no, you can't add a 3rd party GPS receiver to your DJI drone. There's no software interface for such accessories.

 

[Meta4]

I've heard horror stories about flyways when the GPS signal started at 7 or 8 and the pilot hoped the signal would get stronger once airborne, but GPS signal was lost and the drones flew away....

Even if you've heard it, losing GPS does not make your drone "fly away".

Tried flying around a couple of my favorite local Oregon waterfalls this weekend--but couldn't get a good GPS fix. At one location I got 8 satellites.

So I've seen people put Go-Pros on top of their Mavic series drones and certainly an add-on GPS receiver would be smaller than that, is this doable?
Do the more expensive drones have better GPS receivers? BTW, I had my Garmin Inreach Explorer+ with me at all the waterfall locations and it of course had a strong signal.....

The number of satellites your drone can receive is dependent on how much of the sky is visible to it.
If you fly under cover or in a canyon where much of the sky is blocked, many of the satellites will also be blocked.
If you want better GPS signal, you have to fly out in the open where the drone will have a good skyview.
More sky = more sats
An add-on GPS unit won't make up for the satellites being blocked by terrain or obstacles.

And no .. more expensive drones don't have better GPS receivers, particularly when the problem isn't the GPS receiver.

 

[fGene]

Long time ago when I was flying a Microkopter, there was an add-on called Microkopter GPS Shield (google it if you are interested). It worked in a way similar to patch antenna and GPS reception was noticeably better after installing it. I suppose if you are a DIY-er you can make a similar shield for the Air 2, although I don't think it will be easy.

Do the more expensive drones have better GPS receivers?

Possibly, but I am not sure how much better they could get, unless more than one GPS receiver used simultaneously (Inspire 2 comes to mind). The trend always was that newer devices had better performance, and Air 2 is among the newest.

 

[Meta4]

the GPS signal is also affected by the time of the day the satellites are tracking overhead and the number of them nearby.
Maybe look at using UAV forecast, which will give you a estimate of satellite lock for a particular location at a particular time, to figure out the optimum time to visit your locations.

Looking at UAV forecast for GPS is completely unnecessary.
There are always more than enough satellites visible in the sky anywhere, any time of the day.

 

[Nonprophet]

Even if you've heard it, losing GPS does not make your drone "fly away".

The number of satellites your drone can receive is dependent on how much of the sky is visible to it.
If you fly under cover or in a canyon where much of the sky is blocked, many of the satellites will also be blocked.
If you want better GPS signal, you have to fly out in the open where the drone will have a good skyview.
More sky = more sats
An add-on GPS unit won't make up for the satellites being blocked by terrain or obstacles.

And no .. more expensive drones don't have better GPS receivers, particularly when the problem isn't the GPS receiver.

My Garmin handheld GPS in my pocket (i.e. same location as the MA2) had 16 satellites locked in.

 

[Meta4]

My Garmin handheld GPS in my pocket (i.e. same location as the MA2) had 16 satellites locked in.

Can you describe the location where you flew the drone?
Waterfalls usually involve a wall for the water to fall down.
Were you flying where the sky was blocked by terrain or obstacles?

How "same" was the Garmin's location?
Was the drone down close to you with the same skyview as the Garmin?

If you suspect a problem with your drone's GPS and want to compare the drone's GPS with the Garmin, put them side by side out in the open.

 

[fGene]

Waterfalls usually involve a wall for the water to fall down.

AND water, if I may add

 

[Nonprophet]

It's a fairly remote waterfall about 1 mile hike in. Tall trees, old growth forest. I was about 200 yards away from the falls at a vantage/view point. Got RC and phone set up, turned on MA2. Said takeoff permitted and updated home point, but wavering between no GPS bars and 6-7 satts locked in. Because of the terrain, I was planning to hand launch and land. I moved around in roughly a 20' circle holding the MA2 in my hand level, hoping to increase GPS signal. While tall trees all around, I can see fairly large patches of blue sky, and there is an opening directly around the falls in the forest canopy. I remember that I have my Garmin Inreach in my jacket pocket, so while holding the drone in one hand and the remote around my neck with lanyard, I pull out the Garmin, power it up, and check its signal---16-17 satts locked in. Of course I would EXPECT it to have more satts connected--it is a GPS device with a fairly robust antenna--I was just surprised maybe that the MA2 couldn't lock in 11-12 satts in the same location/conditions.

 

[Meta4]

While tall trees all around, I can see fairly large patches of blue sky, and there is an opening directly around the falls in the forest canopy.
I remember that I have my Garmin Inreach in my jacket pocket, so while holding the drone in one hand and the remote around my neck with lanyard, I pull out the Garmin, power it up, and check its signal---16-17 satts locked in.
Of course I would EXPECT it to have more satts connected--it is a GPS device with a fairly robust antenna--I was just surprised maybe that the MA2 couldn't lock in 11-12 satts in the same location/conditions.

OK .. now we're getting somewhere.
Tree cover also blocks GPS signals to some extent.
It's the water in the leaves and trunks that GPS signals cannot pass through.
A branch here and there doesn't make a lot of difference but when you can only see some patches of sky through the canopy, there will be significant attenuation.
If your Garmin is like mine, it has a better antenna and can be used under tree cover .. up to a point.

It sounds like the tree cover was the issue here.
An area like you described does not sound like a great spot for launching or flying and you need to be aware of potential problems in an environment like that.

Your drone's GPS receiver is probably fine.
If you suspect a problem with your drone's GPS and want to compare the drone's GPS with the Garmin, put them side by side out in the open and see how they match up when there is no tree cover.
In most flying situations, the drone is going to have no problems receiving GPS and would possibly pick up more sats than the Garmin.

 

[InvisibleName]

Said takeoff permitted and updated home point, but wavering between no GPS bars and 6-7 satts locked in.

just an observation on this - never a good idea to take-off in this state of GPS lock & signal strength, especially with the potential turbulence in the air from the waterfall - drop into ATTI mode & your drone could be blown all over the place!

 

[Meta4]

especially with the potential turbulence in the air from the waterfall - drop into ATTI mode & your drone could be blown all over the place!

At a distance of 200 yards ??

 

[InvisibleName]

At a distance of 200 yards ??

i don’t know the area, so don’t know the size of the waterfall - my comments are more of a general observation / comment

 

[Meta4]

i don’t know the area, so don’t know the size of the waterfall - my comments are more of a general observation / comment

Neither have I ... but I read his description in post #10.

 

[InvisibleName]

Neither have I ... but I read his description in post #10.

Surely you agree though that, in principle, my warning is correct?

 

[Dave Maine]

200 yards has nothing to do with it. The GPS signals are coming from satellites in orbit hundreds of miles up in the sky. Clear lines of sight between the drone’s receiver and the 10 satellites in orbit is the key.

 

[InvisibleName]

Sorry, are we getting some crossed wires here? I was referring to him taking off with zero GPS signal which could have meant the drone switching into ATTI mode, with the potential consequence of it drifting in turbulent air. Nothing to do with being 200 yards from anything.

 

[Nostris]

The GPS sat, 24 in total, are not geostationary. They orbit at a height of about 20,000kms and each orbits the Earth twice every 24 hours. At certain times of the day more are visible above the horizon, at other times fewer are visible. Occasionally, not enough are visible to fix a position with sufficient accuracy. Usually it’s nothing to do with your drone, it’s to do with how many satellites are visible at the time. Also note. It’s for this reason that many systems also receive the Russian Glonas and European Galileo satellites so they can interpolate between the systems for a more accurate 3d position fix.

 

[sar104]

The GPS sat, 24 in total, are not geostationary. They orbit at a height of about 20,000kms and each orbits the Earth twice every 24 hours. At certain times of the day more are visible above the horizon, at other times fewer are visible. Occasionally, not enough are visible to fix a position with sufficient accuracy. Usually it’s nothing to do with your drone, it’s to do with how many satellites are visible at the time. Also note. It’s for this reason that many systems also receive the Russian Glonas and European Galileo satellites so they can interpolate between the systems for a more accurate 3d position fix.

GPS actually comprises 31 operational satellites, of which 27 are in the baseline slots. GLONASS is 24, making 51 in total, and so the chances of too few being visible to achieve an accurate fix is very small unless you have restricted sky view.