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Some thoughts on the RTH accuracy

A.O.

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Flying a couple batteries the other day and got a "low battery RTH" warning, I almost turned it off like I usually do when it is close by (1000 feet ish) but I thought I would see how close it actually came. I recently purchased one of those 3' round spring open landing pads which was home point. the bird landed dead center of the pad, I was impressed. Second battery and the same warning so I let it do its thing again from around the same distance, different direction.. It was ready to land about 3 feet to the side of the pad, so I stopped it and landed manually on the pad. Still thought the closeness of the landing was pretty good.. something I want to play more with..
 
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GPS drift is only as accurate as it can be. It’s not uncommon to be off by as much as 10’
 
GPS drift is only as accurate as it can be. It’s not uncommon to be off by as much as 10’
Also, everyone keep in mind that the accuracy of the landing depends both on the GPS accuracy of the home point when it acquires it, and then GPS accuracy when it's coming in to land. You get inaccuracies most often when the home point is acquired with just barely enough satellites.
 
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Flying a couple batteries the other day and got a "low battery RTH" warning, I almost turned it off like I usually do when it is close by (1000 feet ish) but I thought I would see how close it actually came. I recently purchased one of those 3' round spring open landing pads which was home point. the bird landed dead center of the pad, I was impressed. Second battery and the same warning so I let it do its thing again from around the same distance, different direction.. It was ready to land about 3 feet to the side of the pad, so I stopped it and landed manually on the pad. Still thought the closeness of the landing was pretty good.. something I want to play more with..

My thoughts, all is correct as stated with GPS. Ever since DJI introduced precision landing in the Mavic Pro (I think, may have had it already in their commercial drones) and if when taking off you met the criteria correctly, vertically up to predetermined height based on model, paused for a sec, then started moving horizontally) you'll hit your target every single flight. Mine messed up once and overshot, but that was due to the wind blowing my landing pad away but it still landed very close. The Mavic Mini 2 does not have or at least does not discuss precision landing in their. But then it's so small, close is good enough for me.

I've attached excerpts from the manuals I have for each DJI drone. Models after Mavic Pro which required 10meters, only require 7 meters now. I just receivedf my DJI FPV on the 11th, so i haven't tested it yet, but as with all my other drones, I'm sure it will perform the same. will keep you posted on that.

It's kind of fun to watch. Once the drone nears and hits it's GPS home location and starts to descend, on the way down it pauses for a sec and adjusts it's position based on the information it recorded on take off and as stated mine haven't missed yet.

Happy and safe flying
Inno



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Mavic Air 2
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Im not convinced precision landing is working on the dji fpv given people with Landing Pads are finding its landing off centre- these have high contrast , so should be relatively easy to land precisely on.

I remember hearing somwhere, that on one of the Mavics precision landing was not available at launch - and was added in a later firmware update - I'd not be surprised if this turns out to be the case on the DJI FPV. ( * )

----

( * ) I've a feeling the firmware on the dji fpv is a bit of a departure from the code base of the mavic series.
It feels like the 1.0 firmware contains all the basics needed, but a little bare bones - in many areas it I'm hoping the first couple of firmware updates might see a few things added back.

in fairness, I will say for a v1.0 firmware - I think the firmware is very stable, they did a good job.
the fact they have not had to rush out a firmware update for the dji fpv is a testament to that!
 
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@inno thanks for the copy from the FPV manual. Has there been an update to firmware and manual adding Precision Landing? Or did I overlook it? I swear it wasn't there at launch!
 
@inno thanks for the copy from the FPV manual. Has there been an update to firmware and manual adding Precision Landing? Or did I overlook it? I swear it wasn't there at launch!
Not really, I've stayed up on all the latest manuals, and it's basically been the same. Version number on the manual is still the same, not updated yet. How precise the fpv's precision landing is... havent tested it yet. But using a high contrast landing pad helps a lot.

In an earlier post, he is right. Cant remember mavic pro or mavic 2, precision landing was not part of the original realease.
 
It was first introduced on the mavic pro. I remember when it arrived, it was so nice landing on my tiny deck.

Did a few take off and landings yesterday just to check out precision landing, and yes indeed, it's right there. I'm coming in within 1 to 2" of my landing spot, every time, if I have a good contrast image below the drone, and a good satellite fix at take off.

It made no sense to me that they would leave it out on a drone that has the sensors, and the codes already implemented in their code base. Glad I was a doofus!
 
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I'm going to have to play with my precision landing a bit. I was a doofus as well, when I got this FPV people were saying it didn't have it and I stupidly believed it. On my Air 2 I always took off and hovered for a bit to let it get its bearings, this one I have not, but will from now on.
 
Hmmmm... now it seems to be operating in imprecise mode... landed 3 ft away from a very good patterned contrasty surface twice yesterday.

Some investigative work is called for here...
 
So I went out to play today and I hardly ever auto RTH land this thing but wanted to try out the precision landing on it, so from different directions and from 1000 to 2000 feet (cant get much farther away due to thick tree cover) I thought I would try it. Conditions were a little breezy but not too bad even though I did get a couple "high wind warnings" on my screen. Anyway , taking off I waited till I got the home point announcement then went straight up around 15-20 feet and hovered in place before flying away and 4 out of 4 times it landed on my 3' Hoodman landing pad!

IMG_5562.JPGIMG_5561.JPG
 
Meh, who needs it :p:D

Landing on tiny enclosed deck with the Motion Controller:

 
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I was poking fun... While I can land manually, I'm the lazy guy always praising RTH and Precision Landing because I use it all the time :cool:

I'm flying more these days with MC than the RC... lots of practice learning to land manually with it. Challenging! As my video above shows, gotta practice coming in at an angle, if doing it FPV.

Much easier LOS, cause you can safely ascend/descend vertically.

Most of my FPV flying the last two weeks has been soaring around the edges of clouds. The MC feels so instinctual and natural flying like a stunt plane in that environment.
 
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So playing around with this again today, the first time RTH it lands right on the pad.
I am always ready, goggles off , so I can watch the bird do what its doing when it arrives at HP so I can take over and land it if need be. The second RTH today, its coming in at set altitude and gets to HP and starts to descend, I noticed as its coming down its about 10 to 15 feet to the right of the HP so I'm just about to turn RTH off to adjust it and land on the pad... when it does exactly that!! At maybe 25-30 feet high it starts to slide sideways toward HP so I let it do its thing, and it lands right on the pad. I've never seen it adjust like that on the way down before, but maybe I've always taken over before it had its chance to do so.
Interesting observation today!
 
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