How Accurate Is Litchi Waypoints

[Flipsonic]

Just installed Litchi and planning a mission for the first time. Has anyone tested how accurate the bird flies to each waypoint? I would imagine that it's not that accurate, maybe a few feet off. If so, how much off is it by?


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[Richard Gozinya]

Why don't you measure it and tell us ?

 

[alokbhargava]

Accuracy of positioning depends on two factors: 1. How accurately you work out the coordinates of your waypoints and next 2. how accurately your drone follows them using its GPS. Litchi doesn't play any role

I have been able to get 3-10' accuracies.

 

[Flipsonic]

Thank you sir!


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[flyNfrank]

I just watch a friends video using litchi waypoints and the mission had 75 waypoints that went pretty good. He owns a number of dji aircraft and uses 2 P3 Standards at the same time both using the same mission. Actually the 2nd aircraft's mission is a little higher in altitude so that it looks downward on the lead aircraft which is usually some 30ft to 50ft out in front.

He says the coordinates are based on google's longitude and latitude entries. You can see each aircraft has variances from the other. Their distances from objects are not a carbon copy from one another.

 

[Richard Gozinya]

Accuracy of positioning depends on two factors: 1. How accurately you work out the coordinates of your waypoints and next 2. how accurately your drone follows them using its GPS. Litchi doesn't play any role

I have been able to get 3-10' accuracies.

I'm having a hard time with step 1 NOT being a given.

 

[MikeON]

I think many people on these forums have unrealistic expectations of the accuracy of consumer-grade GPS. Using auto-land, my P3A will sometimes come down within a foot of takeoff point, but other times it might be off 25 or more feet. I usually take over control before touch-down. I've been using hand-held GPS for many years and noticed the same variations. The same considerations would apply to waypoints in Litchi.
Surveyors can achieve much greater precision using sophisticated equipment with multiple receivers.
Trimble - GPS Tutorial - Surveyors Do It Differently

 

[Mark The Droner]

You might find this thread interesting: "Follow the Leader"

The OP flies two birds at once on the same Litchi mission - through the city of Baltimore - especially the Inner Harbor - except the second mission is adjusted to be 25' away from and behind the first mission at all waypoints. You're watching from the second bird. He starts off launching at the same time with the birds 25' apart. But at the end of the mission, he says the birds appear to be about 100' apart (see posts #9 and #22).

See his video here (and I strongly suggest you max the screen):

Tangent: Note the bright yellow flashing of the tail lights indicating loss of the control signal.

 

[Meta4]

Just installed Litchi and planning a mission for the first time. Has anyone tested how accurate the bird flies to each waypoint? I would imagine that it's not that accurate, maybe a few feet off. If so, how much off is it by?

Consumer GPS is going to put your Phantom within 1-2.5 metres most of the time but occasionally it will be further out.

 

[engineerus]

Accuracy test

 

[cstangor]

I thought it would be possible to pretty much superimpose consecutive photos at the same waypoint on top of each other from mission to mission. Sadly, that is not the case. The POI wanders around substantially in the frame from mission to mission. Anyone have any experience with this?

 

[Avocet]

One thing I've tried is I always produce a KML export from a Litchi mission and compare it to the user interface in the Litch Hub's flight path, as an eye test. It's very very close from altitude (the Hub only lets you zoom so much AGL). I will say this, a waypoint mission (and orbit missions too) have always worked flawlessly with respect to interpolation of POIs as the mission progresses - no missed or wonky views of POI targets and now surprises with camera framing, etc. It's close enough to capture what I ask of it and that iS the intent.

The "chase" video above from Mark the Droner doesn't go into a lot of detail. Looks like he cloned a mission and then adjusted the alt of the waypoints. It also looks like other attributes were altered. The birds seem to do different things at different times? Intentional? Dunno ... I've seen this vid when it came out a while back when rule breaking was a learning curve!

My dos centavos ...

 

[Drone Freedom27]

Litchi waypoints are pretty good.ive used them and I've set missions that are well outside my video transmission range and I lose connection but it keeps gps and continues flying the course and then returns home eventually it's scary when you disconnect and you have to wait for it to return or not but mine always returns. Also watch on youtube there is lots of litchi missions and proof of accuracy. The only Bad thing about litchi is it has a 10% battery safety guard and you cant change it or cancel it once your battery hits 10% you land on whatever is below you. So if you want to use every bit of battery for long flights use Dji GO app but if you want more features and a easy cheap way to fly FPV goggles use Litchi.

 

[Avocet]

I thought it would be possible to pretty much superimpose consecutive photos at the same waypoint on top of each other from mission to mission. Sadly, that is not the case. The POI wanders around substantially in the frame from mission to mission. Anyone have any experience with this?

Let's be clear here. The POI is not wandering, but the drone is. Even when hovering. Variables in conditions, wind, temperature, density altitude, humidity, battery state, control input, extraneous electromagnetic activity, light all will make an attempt at defeating an object suspended in our atmosphere. The plus/minus error is quite measurable for just about any object suspended or moving through our atmosphere.

We tend to think of "air" as a nothing. Stand below a glider doing 80 knots as it flies right over head. The roar made by the violence of the air and the surfaces of that machine will make you think about air in a completely different light.

Ooops, sorry, I digress,