First off I love Virtual Litchi Mission and find the planning and design process easy and fun to do. Sitting back and watching the flight is like being on this giant scenic monorail and makes it easy to spot areas where speed, altitude or camera angle need to be modified. My Question is just how reliable is the overall Litchi system in the real world when dealing with position and altitude? Power lines, trees and other obstacles need to be scouted first and the GPS signal strength is critical but after that will the drone be where it is supposed to be or is there a Variability of a few feet in all directions? Are there other things that can alter a drones preplanned course that we should be aware of? Thanks!
VLM is very reliable and realistic with the following caveats:
- Neither VLM nor Litchi are aware of what your take-off (home) location will be. Since the drone’s altitude is measured from its take-off location, VLM and Litchi must assume that your take-off location is at the same altitude as waypoint 1.
- Consumer GPS is only accurate up to plus or minus one meter. This is neither a fault of VLM nor Litchi. It is just a limitation of the technology.
- Trees grow. Since maps can be years old, be careful when planning missions near them. They may be much higher and wider that what is shown in Google Earth Pro.
- Each model of drone has a different Field of View (FOV). Unless the FOV of Google Earth Pro is set up to match that of your drone, your view will look different.
Keep in mind that VLM and Google Earth Pro are separate products from Litchi. Each has their own limitations. After planning a mission at your desktop, your first flight of that mission needs to be watched carefully as it is flown for the first time. Each time you make subsequent flights of that same mission, there will be slight variations in the position and height of your drone due to GPS accuracy and changes in take-off location).
Thank you wesbarris for the help on this issue! This detailed answer is very helpful to me and hopefully other pilots as well.
You can count on an accuracy of about 10 meters.
On this forum, a question about gps accuracy was very often asked, for some it ended with a broken drone
Wow, 5-10 meters of unpredictability in all directions is dangerous unless you are well above all obstacles! I had been planning on doing some tight missions up and down rivers and streets as well as through building corridors but now I am not so sure what is safe. Insurance companies might even refuse coverage for certain missions. Thanks paxxa!!
You can fly the drone during the mission, just be prepared to use the sticks
wesbarris, have you had any problems with Litchi positioning recently? I was referred to a Forum post where a number of Litchi users were having their positions off by between 5-10 meters which is way off the norm of 1m as you mentioned. Thanks.
Nonsense. Anyone who has planned and flown missions will know that it is much more accurate than ± 10 meters (30 feet). You generally will see better than ± 2 meters. Usually ± 1 meter. If you are only seeing an accuracy of ± 10 meters something is wrong and you need to do some troubleshooting.
These forum threads were not created by me.
Thanks wesbarris and paxxa, you are both helping to hash out a very important issue and I appreciate all the effort and time taken. I can see that this is going to take time and practice for me to be a safe and informed pilot. Unless there are differing viewpoints, there can be no debate.
No, but the 10 meter accuracy statement was.
Anyone with any experience with flying missions will know that the accuracy is better than 10 meters. If the accuracy was really that poor, we would all be crashing our drones. You should know better than that.
I can only find a few more threads on the forum where this problem was mentioned.
I remember there was a case when mini crashed into the wall of the house, it was quite recently.
So you found one post from about 6 months ago from someone with an unknown GPS problem and you automatically assume that is the norm? Doesn’t your own experience tell you anything different? Wouldn’t you say that is a bit irresponsible of yourself?
I see a gps error of about ±5 meters.
In any case, this is not enough to fly into the gate, the drone will definitely crash
Seems like a similar thread 2 months ago
You are confusing wind or possibly signal strength issues with GPS accuracy.
Thanks to you both paxxa and wesbarris, I feel stronger going into this Litchi drone world. While there is plenty to read, some of the learning is finding out what is real and which is rumor or odd glitches caused by who knows what. While guarding against rumor or false statements is vital, I now feel more prepared since I am more confident that the majority of the time the drone will behave properly but also to always expect the unexpected. I will keep you both informed as I venture out and gain more confidence as time goes on. This is a great community and I am proud to be part of it, so keep up the good work!!