DJI Mini + Litchi + improved accuracy - RTK?

General Drone Discussion
1

I bought a Mini 3 in 2022 with the intention of flying it around a (planned) route round my garden to record what was flowering when etc.

I asked for advice on here and Litchi was recommended.

Original thread: DJI Mini 3 Pro - repeat route / fly my garden through the seasons

At that time Litchi not available for the Mini 3, so I bought a Mini 2 and tried that.

GPS nothing like accurate enough - I would “train” it down a path, then repeat on another day, and it would fly far enough off course to hit a plant.

I had a go (on the “repeat the route” days) at recording a new Litchi file for a specific location / route, I then adjusted all the waypoints of my original saved plan (by the change in offset for my “specific location” plan), accordingly, and that worked (provided flown “immediately”). But I didn’t have an easy way to bulk-edit the waypoints, nor the time to engineer something (I have software skill, but not much time)

I parked that project - too much else on …

Separately I had a robot mower. The sort with a, buried, wire around the boundary and the mower goes back and forth, at random, until it encounters the wire.

If the wire breaks that’s a hassle. If it is me being an idiot with a spade then I know where that was, not too bad, an animal normally leaves evidence, so worse but tolerable. But I have started to have increasing numbers of wire problems and I suspect is that the insulation is breaking down and the signal leaking / becoming too weak for the mower.

I discovered that robot mower now available with RTK GPS correction. Bought one of those, and it is night-and-day better than the “boundary wire” solution - mower position accurate to a CM or two. That’s another story …

But if I could have RTK on the Mini 3, with Litchi, I could resume my “repeat route / fly my garden through the seasons” project. My thought is that Litchi could adjust the plan, that the Mini flies, using RTK to adapt the original plan (and fly the revised plan). Maybe Litchi could just require that Mini was placed on a guaranteed-repeatable spot, and use that for the adjustment and thus not need expensive of RTK base station (I have no idea how long the revised GPS data would be valid, but my individual flights are very short)

And if I could use the Mower’s RTK base station (which cost and arm and a leg) that would be great. I imagine that their signal-to-mower is proprietary … but maybe not.

Am I fresh-out-of-luck with Mini + Litchi + RTK?

Maybe I should just have bought a Phantom RTK (although “Buy now” says “Not available in your region”) and I am sure more money than I would like to pay - I only have this usage for a drone, not something I want to develop as a hobby.

But that said I am open to ideas - including that existing Mini + Litchi could be persuaded to fly a route more accurately by some other means

2

Are you planning the route in LitchiHub?

3

I think so (sorry, its been a while since I used it at all). I am using

https://flylitchi.com/hub

I have managed to log on to that, with an old login, and I have a number of Missions stored, and I can load those into the Litchi APP on my phone

EDIT: I also have “Virtual Litchi Mission 2.8.1 by Namirda” on my PC. It looks vaguely familiar but I’m not sure if I ever actually used it

4

My mini 2 and Litchi works perfectly on gps and routes. Love it.

5

I’m flying along a “corridor” path 2M wide at a height of a 2M. My repeat flights are not reliably within that corridor (route is recorded dead centre down the path, so there is 1M of latitude each way, my Mini will be outside that on some repeat flights)

I presume this is “normal” rather than “just me” due to the normal GPS tolerance?

If I was flying higher I would be above any obstacles and I doubt the accuracy would be a problem from a camera-position perspective either. But I want low level photographs

6

GPS accuracy is generally 3-5 metres, your margins are just too low.

Go Pro on your mower?

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7

Get a cheap Mavic 2 Zoom, fly higher, zoom in!

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8

The DJI mini is not accurate enough for this, you will need to spend a lot more on a drone to get that

Or use a camera dolly

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9

Thanks, I thought that was the case for GPS (hence RTK would be of interest), seems (well … to me!) that Litchi could implement that on a stored route plan, combining it with data from an RTK source, as part of sending it to Mini. Some mower brands are working on “An RTK source nearby” rather than buying one specifically for own property (I think their plan was to roll out nation/worldwide network of RTK base stations)

Interesting idea, because mower will quite happily drive a route (to get to “an area to be cut”), but I want camera PAN and TILT and so on. Maybe strap the Mini to the mower!

Can the mini follow the mower? (seems likely) and PAN etc. from a repeatable script? (I reckon that will be tricky?)

10

Insta360?

Not reliably as it does not have the sensor capability and relies on clever (not that clever) software using the camera to track.