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Comments
43 comments
With the latest beta, the distance is either the distance from the drone to the home point (when you select home) or from the drone to the mobile device (when you select device, which suffers when the device does not have GPS - the whole reason we created the option). The real test here is to have the flight dashboard open with home selected for distance, and then turn the drone on and just let it sit there on the ground and when you see the home icon show up on the map, see what the distance says. Then let it keep sitting there and watch the distance change as the GPS error drifts about.
Jim that is approximately what I did. I turned on a mission and let the drone sit until home is recognized and it said the drone was 12 feet away. It varied each time I did it. I then hand flew it to a point that was 107 feet away and it said that the drone was 90 feet away. I use the modern dashboard because it shows lat. And long. I then put the coordinates into a program that calculates the distance and it says 106 feet. I think the discrepancy is because I am hand flying the drone with the mission on. I am going to create a mission to fly a much more distant point to point that I know what the distance is.
I don’t fly my My often but it has always been less accurate then my MA2. The reported Distance is always more off and doesn’t land on home-point as close. Maybe something to do with each drone but not sure. Maybe I’ll fly the MM soon and do some tests. For me It doesn’t matter if it’s 6’ to 10’ on the telemetry, as long as it’s 3 feet to literally inches within my launch spot which is common. At least for me and my purposes.
Yeah I'm pretty much the same, was hoping to get out and do some testing today, but the weather was Carp
Do you see the actual drone coordinates changing on screen? If so, even if the drone is not moving, DL has no way to know this because the telemetry from the DJI SDK says otherwise. This is the GPS drift that everyone keeps referring to, and we have seen it as much as +/- 4m.
I think I figured it out. If I start the program and just leave the the drone on the pad without launching it, it can show anywhere from 9 to 12 feet distance when it should be 0. When I start the program and the drone actually takes off, the distance changes to .6 feet. The mission was to fly to a pre-measured location and hover over it and get a distance measurement, the drone said 312 feet and the laser said 310.56. That is really good, but if I just hand fly it by turning everything on but not actually activating the mission and then launch the drone with the sticks and hand fly it to the location the distance can be off as much as 15 feet. I will try some more testing this evening when the winds diminish.
I think the accuracy is sporadic. I just flew a mission and hand flew from and to pre-measured locations and they were not more than a foot or 2 off, even DJI was really close. The biggest discrepancy was in the Lat. and Long. calculation, but even that was not bad. The coordinates said it was 6 feet further. So I think this subject is dead.
I finally got down my local flying field yesterday, which is home to the local rugby club and flew some tests, and created this video
https://youtu.be/2Bam4xsY3zU
Thanks for the video, Martin.
A few thoughts.
From the start, even when on the ground, the drone is showing a couple of meters away from the home point. This is not uncommon - GPS is just not that accurate and the home point sets as soon as it gets about 8 sats, so as it improves with more sats it will naturally move from the "home point".
Overall though, everything you showed seems within the level of tolerance for GPS from what I understand, so I guess that is a good thing!
Cheers for your comments Barry Houldsworth, yeah that was my take on the results as well, don't think you can complain about a few meters difference here or there
Yeah I think everything is working fine. But as I said, when I flew just sitting on the pad was 9 to 12 feet but as soon as I launched it went down to .6 feet, that I think is a little strange, the # of sats did not change! Also strange is that the coordinates when calculated were 6 feet different than the reported distance. But still all within acceptance.
DJI automatically updates the home point to the current location when the drone takes off.
Even though DL doesn’t have an actual audible “Home-Point has been updated” like with DJI app, there is a way to tell before it launches and again after it launches. You can tell if the drones home-point has been updated before take-off by seeing the little “Arrow” icon which is the drone. Once enough satellites are acquired and the arrow is displayed the drone is ready to go.
The other way may vary with different drones but the rear green LED Lights on my MA2 flash about 10 times quickly right after launching which means it’s being updated again. The same for my MM except it only has the front light but does the same. I notice this awhile back when using the DJI app and after launching it gives the audible at take-off and lights flash at same time.
Just some additional info to ensure when using DL that home-point is recorded which will make it as accurate as it possibly can be. It’s all automatic but sometimes patience’s and paying attention to the app pays off. Enjoy everyone.
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