How many satellites for your home point to be updated? (Poll)

[Let Us Drone]

Hello!

I apologize if this topic seems redundant, but I would like to gather research on what the minimum amount of satellites you personally need for your Phantom's home point to be updated?

I realize that there are a lot of threads that discuss this, but from what I've seen, there really isn't a definitive number of satellites that is required. So, what's your personal experience? Cast your vote! Thanks in advance for your participation...

Regards,
Trevor

 

[3rdof5]

I've never got the green "safe to fly GPS" on my P3P with less than 6 satellites. Just my experience.

 

[With The Birds]

Are you interested in knowing which phantom Model?

Hard to appreciate what you might be trying to achieve. Home point can be set when there is sufficient positioning information for P-GPS mode to be available. Generally this will be 6 satellites acquired.

 

[With The Birds]

I've never got the green "safe to fly GPS" on my P3P with less than 6 satellites. Just my experience.

I suspect that will be everyone’s experience.

 

[David_Cambridge]

I am a little confused by the question’s wording. The home point is only updated when the drone is in flight, and the pilot requests it, and there are enough satellites. The home point is set initially at takeoff if the proper number and signal strength of the satellites are present.

 

[msinger]

I am a little confused by the question’s wording

The OP is likely referring to the number of satellites needed before the home point is auto set after the motors are started.

 

[Loz]

Arguably (and I don’t wish to) a gps location on earth fix is possible with just 4 satellites signals being received, three technically without altitude, but I’ve no idea what DJI programme their min to be, for home point fix. With so many available now that GLONASS is included, 6 sounds quite reasonable as a minimum.

 

[With The Birds]

Arguably (and I don’t wish to) a gps location on earth fix is possible with just 4 satellites signals being received, three technically without altitude, but I’ve no idea what DJI programme their min to be, for home point fix. With so many available now that GLONASS is included, 6 sounds quite reasonable as a minimum.

6 seems to be it for the Phantoms. My suspicion is it is higher for the Mavic. I would say 8 as a guess.... I base these numbers on direct experience and observation. Specifically occasions where I have noted the satellite count where DJI GO reported P-GPS mode being active and homepoint recorded with the AC’s powered up indoors.

 

[African wildlife]

We almost always wait until the green GPS confirmation light is on before taking off. For us, this happens extremely quickly - within less than 20-30 seconds - so we don’t usually check how many satellites have been acquired. Our skies here are even bigger than those in “big sky country” Montana!

 

[Let Us Drone]

The OP is likely referring to the number of satellites needed before the home point is auto set after the motors are started.

Yes, that’s correct [emoji1303]

 

[skymonkey]

I checked today and it was 10 until home point updated.
Sunrise Florida

 

[sar104]

A quick look at a dozen or so DAT files shows that the home point is set when the pDOP value drops to 2. How many satellites that requires depends on constellation geometry and local factors that affect signal quality.

 

[With The Birds]

A quick look at a dozen or so DAT files shows that the home point is set when the pDOP value drops to 2. How many satellites that requires depends on constellation geometry and local factors that affect signal quality.

Is there a typical number of satellites providing for that condition. I’m going to say it’s 6 plus from direct observation of what is reported in the go app.

 

[sar104]

Is there a typical number of satellites providing for that condition. I’m going to say it’s 6 plus from direct observation of what is reported in the go app.

From those same DAT files the total number of satellites varied from 8 to 13 when the pDOP value became 2. Separately, I don't think I've ever seen the home point set with fewer than 8.

 

[3rdof5]

Here's an example of 6. My P3P in my living room.

 

[sar104]

Here's an example of 6. My P3P in my living room.

Are you sure that it didn't have more than that just prior to the image? That also shows a nav health of just 3, which is below the usual threshold for P-GPS.

 

[3rdof5]

No it was jumping between 4 and 7. Everytime it went below 6 it went into atti mode but 6 and up stayed green in the app and the rear arms of the AC

 

[With The Birds]

Here's an example of 6. My P3P in my living room.

That has been my experience also.

 

[sar104]

No it was jumping between 4 and 7. Everytime it went below 6 it went into atti mode but 6 and up stayed green in the app and the rear arms of the AC

It would be interesting to see the pDOP values while that was happening.

 

[3rdof5]

It would be interesting to see the pDOP values while that was happening.

Am I able to post that info? Props were running atm. There will be a flight log.