Mini 2 distance shown in app

[vulcanclassic]

Hi all
I'm a new Mini 2 owner and I've noticed the distance to the Mini 2 shown in the app says 20-30 ft even when it's sitting less than two feet away. The distance seems to become more accurate as the Mini 2 moves further away, but when I bring it in close the distance starts to increase close in rather than decrease. Is this normal? Is this something to do with the rx and tx being to close to each other? Really not sure. Was wondering if this will effect the RTH accuracy? How accurate is the RTH in general? I live where there are trees everywhere. Is it reasonable to expect to takeoff (of course having good satellites) within 20 ft of trees and have it RTH with enough accuracy to clear those same trees at takeoff point? I'm proceeding slowly as not to get into any trouble, but if some of you more experienced users could shed some light here that would be great. Thanks!

 

[Dronut]

G'day vulcanclassic. Here's the specifications from the manual-

Hovering Accuracy Range
Vertical: ±0.1 m (with Vision Positioning), ±0.5 m (with GPS Positioning)
Horizontal: ±0.3 m (with Vision Positioning), ±1.5 m (with GPS Positioning)

I took some photos for a timelapse video this morning. I took off from a hover from the middle of two shrubs and a tree, about a metre from the ground. The drone was about a metre from any one of them. I was after a nice timelapse with the paddocks beyond my place on the other side of a tree lined creek. I sent the drone straight up to 120 metres and let it do its stuff for 20 minutes, just hovering. Then I brought it straight down to a hover within ten centimetres from where I took off. So even though it was a little windy up above, the drone stuck to its GPS position really well.

I've never had a problem with RTH. It always comes back to where the home point was set. I always hand launch and hand catch and I've never had to move from where I sent it up to go catch it.

 

[Deleted member 103366]

With regards to indicated distance it might be as well for you yourself to see what the RTH behaviour of your drone is when 'close'. There is/are distance threshold/s where the behaviour changes, if the 'error' affects that/those thresholds you could be caught out by the subsequent unexpected behaviour.

With my Mavic Mini, RTH is normally accurate to within 4 or 5 ft, often within 2 to 3ft.
That said, before relying on it for a real flight, I often send the drone out a short distance and then RTH it just to verify where it thinks home is set. This stems from a couple of flights where, with a different drone, the homepoint was inaccurate and the error would have brought it down into a fir tree.

 

[Meta4]

Hi all
I'm a new Mini 2 owner and I've noticed the distance to the Mini 2 shown in the app says 20-30 ft even when it's sitting less than two feet away. The distance seems to become more accurate as the Mini 2 moves further away, but when I bring it in close the distance starts to increase close in rather than decrease. Is this normal?

The most likely explanation for this is that you didn't wait for the drone to record a homepoint before launching.
The distance shown on the screen is the distance of the drone from the homepoint.
It should always be accurate within a couple of feet.
The drone records a homepoint when it gets good GPS position data.
If you launch prematurely, your homepoint will be off wherever the drone was when it did get enough satellites for good data.

Post your flight data and that will confirm if this caused what you observed.

 

[Meta4]

That said, before relying on it for a real flight, I often send the drone out a short distance and then RTH it just to verify where it thinks home is set.

All you need to do is look at the distance shown on the screen.
It's the distance to the homepoint, so you can always easily tell where the drone has recorded its homepoint..

 

[Deleted member 103366]

All you need to do is look at the distance shown on the screen.
It's the distance to the homepoint, so you can always easily tell where teh drone has recorded its homepoint..

Sorry but in the circumstances of the flights I mentioned I would have to disagree. The indicated distances would have been the same or too similar to discern that the homepoint was inappropriate.

 

[umanbean]

Not a Mini 2 but...

The indicated distance in GO4 flying my MPP is often incorrect when the drone is close, and so is the altitude when low - and I always wait for adequate sat lock and HP recorded. I do understand that 'consumer-level' GPS is not exactly accurate to within less than 7-10ft. sometimes.

Still, RTH is very reliable in bringing it back very close to HP - then I'll sometimes cancel RTH at altitude and bring it in manually, sometimes let it descend to ~10ft. before canceling.

When VPS is ON at takeoff and I use the 'Precision Landing' option to launch, it lands itself on my launch pad within inches of takeoff point... sometimes within 1"

if ;tldr then-

Is it reasonable to expect to takeoff (of course having good satellites) within 20 ft of trees and have it RTH with enough accuracy to clear those same trees at takeoff point?

Yes, I do it all the time. In fact, as soon as day breaks I'll be doing it this morning.

 

[Meta4]

Sorry but in the circumstances of the flights I mentioned I would have to disagree. The indicated distances would have been the same or too similar to discern that the homepoint was inappropriate.

Nonsense
When you startup .. watch as the drone gets GPS and the indicated distance changes from N/A to a number.
If that number is really, really small (like 1 or 2 feet), that proves that the homepoint is (as you would expect) exactly where the drone is sitting.
That's a perfect confirmation of what you are unnecessarily trying to achieve.

 

[umanbean]

When you startup .. watch as the drone gets GPS and the indicated distance changes from N/A to a number.

I just did that, with 12 sats and 4 of 5 bars on the GPS health scale. The number starts out small, then fairly rapidly ticks up and up, topping out at 20.7 ft... then wanders around up and down.... just glanced at it, and it's at 31.2 ft. right now

H=0.0 until I arm the motors, then goes negative and eventually settles around -4.3 ft.... it's on -3.6 ft. now and wandering.

 

[Meta4]

I just did that, with 12 sats and 4 of 5 bars on the GPS health scale. The number starts out small, then fairly rapidly ticks up and up, topping out at 20.7 ft... then wanders around up and down.... just glanced at it, and it's at 31.2 ft. right now

H=0.0 until I arm the motors, then goes negative and eventually settles around -4.3 ft.... it's on -3.6 ft. now and wandering.

Can you post the data from that and I'll have a look to work out what's going on?

 

[umanbean]

Can you post the data from that and I'll have a look to work out what's going on?

I'll give it a go, read a lot about posting logs, but never done it myself... do you want the txt or dat?

 

[Meta4]

I'll give it a go, read a lot about posting logs, but never done it myself... do you want the txt or dat?

Txt file is all that's needed

 

[umanbean]

Txt file is all that's needed

uh oh... I've fired it up so many times this morning (8), in different locations around my backyard, I can't remember which one it would be. I'll review my Flight Records in GO4 and see it I can get the right one... might upload some to PhantomHelp see if I can narrow it down.

Sorry for the trouble, thanks for offering to help!

 

[umanbean]

Txt file is all that's needed

@Meta4
Pretty sure this is the one, I can go ahead and upload to PhantomHelp if you want me to, save you the trouble.
Thanks again

 

[Deleted member 103366]

Nonsense

Well we will have to disagree.

 

[Meta4]

@Meta4
Pretty sure this is the one, I can go ahead and upload to PhantomHelp if you want me to, save you the trouble.
Thanks again

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

With that one, what's happening is that the homepoint has never been recorded.
It looks like there was some tree cover that probably was affecting GPS reception.

The drone was sitting there for 5 minutes with satellite numbers were 11-13, but GPS Health never went past 4/5.
Often that's enough to record a home point but the flight controller didn't think everything was perfect so didn't record a home point.
It had location data but wasn't satisfied of its quality.
If you tried again, but out in the open, it should be quite different.

I'm surprised that it was showing a distance figure at all.
But the important thing is to check that a homepoint is recorded and then check the distance shows that the drone is on top of the home point it recorded.

 

[umanbean]

With that one, what's happening is that the homepoint has never been recorded.

OK, that's key... I didn't notice that Sheila never said 'home point has been recorded, please check it on the map' ?... appreciate the assist!

BTW, I deleted the txt attachment in my last post

 

[Meta4]

Sorry but in the circumstances of the flights I mentioned I would have to disagree. The indicated distances would have been the same or too similar to discern that the homepoint was inappropriate.

Sorry but I can't understand what you are saying.
Can you explain how checking that the indicated distance is within a foot or two, when the drone is sitting on top of the home point, isn't a useful confirmation of where the home point has been recorded (and thus the spot the drone will return to if you leave RTH to bring it back and land)?

 

[Deleted member 103366]

In the flights that I mentioned in posts 3 & 6 the drone had indicated the it got a homepoint fix as it took off, the rear LED's flash in a specific way.
Later, when I RTH'd it, the home point it returned to was not the take off point but about 20ft, perpendicular to the RTH flight path, away, where a fir tree lay in wait.
I can not comment on what the indicated distance from the 'homepoint' was, either at take off or at arrival over the fir tree as I do not remember them, even if I noted them at the time. My reference to checking distance in my other posts in this thread was in relation to my drone when my drone was at distance.
Irrespective of our two viewpoints, doing a short distance RTH to check the working location of the homepoint does no harm

 

[Meta4]

Later, when I RTH'd it, the home point it returned to was not the take off point but about 20ft

The only logical explanation is that your home point was recorded after taking off, while you were flying away.
Your flight data would confirm if this is so.

If you want the drone to come back and land where you launched, using RTH, you shouldn't be flying off before you've seen the homepoint recorded.

And launching vertically is a good way to ensure that if the homepoint gets updated soon after launch, that it will be where you want it rather than some distance away.

When your drone records it's home point, check the indicated distance and it will confirm where it's home point is.

Irrespective of our two viewpoints, doing a short distance RTH to check the working location of the homepoint does no harm

It is unnecessary and indicates a lack of understanding of how homepoint recording works.