GPS accuracy during crash

[tmarsh0494]

First time posting. First time crashing my spark. 100% my fault. Was flying in sport mode, during the day in full view, at about 80'. Which wasn't enough to clear this group of trees but I thought that the spark was going to go in front of the trees, from my perspective. The spark hit the tree and I watched it go down. Immediately lost transmission and was disconnected on impact. Im assuming either the battery fell out, or it landed in the small creek.

Here is the flight data: DJI Flight Log Viewer - PhantomHelp.com

I immediately used the Find My Drone feature to go to the exact spot that it said to go to, which is also roughly where I watched it go down, but I cannot find it. Myself and 7 others spent hours looking for it. The ground is covered with dense grass and brush. I was able to find 2 pieces of propeller, but not the spark itself.

So my question: during a crash, how accurate is the GPS? I feel at this point it is not anywhere where it says it is, but I've also looked everywhere within reasonable distance of the tree that took it down. Its frustrating that I can't find it, it has to be there somewhere.

 

[Heckmaniac]

I found it to be extremely accurate when mine went down in a field of overgrowth. That said, the coordinates are only showing you the last point where it had power. Depending on how high you were and the speed you were going will determine how far from those coordinates the drone may have gone. I would agree that with 7 people and hours of looking that the drone should have been found. How far away was the drone from where you were (is it possible someone was there and took it before you arrived)? Could it be in one of the tree tops out of view from the ground when looking up? Sorry to hear, best of luck continuing your search.

 

[tmarsh0494]

Alright, I found it. It was about 15 feet away from its last coordinates. Which is odd. The tree it hit, has a creek next to it, and then a trail next to that. The flight log shows it hit the tree, crossed the creek, and landed on the trail. But of course, it was in the creek.. I pulled it up from under the muck and leaves with a rake.
I brought it home, tore it down to the circuit boards, was still wet so I washed the mud away with a little water, blow dried everything and it is in a tub of rice until further notice. The battery however still shows 3 bars worth of juice, so maybe there is hope. I did not try to power the drone.
Am I going about this the right way?

 

[H3Alpha]

15 feet from it's last coordinates are well within typical GPS accuracy. In other words, it was right where it said it would be.

 

[Nope 2.0]

First time posting. First time crashing my spark. 100% my fault. Was flying in sport mode, during the day in full view, at about 80'. Which wasn't enough to clear this group of trees but I thought that the spark was going to go in front of the trees, from my perspective. The spark hit the tree and I watched it go down. Immediately lost transmission and was disconnected on impact. Im assuming either the battery fell out, or it landed in the small creek.

Here is the flight data: DJI Flight Log Viewer - PhantomHelp.com

I immediately used the Find My Drone feature to go to the exact spot that it said to go to, which is also roughly where I watched it go down, but I cannot find it. Myself and 7 others spent hours looking for it. The ground is covered with dense grass and brush. I was able to find 2 pieces of propeller, but not the spark itself.

So my question: during a crash, how accurate is the GPS? I feel at this point it is not anywhere where it says it is, but I've also looked everywhere within reasonable distance of the tree that took it down. Its frustrating that I can't find it, it has to be there somewhere.

I had the same GPS problem when my spark chased. I'd say from only personal experience that the GPS isn't all that accurate in the case of a crash. same story Dense bushes sports mode and tall trees no creek but a massive deep freshwater lake. The GPS said I did 63 mph a went up 6000 feet. so I personally would 100% trust the GPS.

 

[Nope 2.0]

15 feet from it's last coordinates are well within typical GPS accuracy. In other words, it was right where it said it would be.

I can't agree with that but it's a good rule of thumb

 

[H3Alpha]

I can't agree with that but it's a good rule of thumb

Can't agree with what, the typical accuracy? Take a look at any handheld GPS unit, or any GPS app on your phone that shows it's accuracy. For anything under 15' accuracy, you will need either perfect conditions (maximum # of satellites, evenly spread out across the sky, no trees/buildings, etc), or high dollar commercial surveying GPS equipment.

Here's an explanation:

"The United States government currently claims 4 meter RMS (7.8 meter 95% Confidence Interval) horizontal accuracy for civilian (SPS) GPS. Vertical accuracy is worse. Mind you, that's the minimum. Some devices/locations reliably (95% of the time or better) can get 3 meter accuracy.
For more general GPS accuracy information, head to GPS.gov's website. That website also includes data and information on WAAS-enabled systems and accuracy levels depending on location. It's a great resource.
Basically, you can't get 2 meter accuracy reliably without some form of correction."

Here's a good site for GPS accuracy info

 

[Nope 2.0]

Can't agree with what, the typical accuracy? Take a look at any handheld GPS unit, or any GPS app on your phone that shows it's accuracy. For anything under 15' accuracy, you will need either perfect conditions (maximum # of satellites, evenly spread out across the sky, no trees/buildings, etc), or high dollar commercial surveying GPS equipment.

Here's an explanation:

"The United States government currently claims 4 meter RMS (7.8 meter 95% Confidence Interval) horizontal accuracy for civilian (SPS) GPS. Vertical accuracy is worse. Mind you, that's the minimum. Some devices/locations reliably (95% of the time or better) can get 3 meter accuracy.
For more general GPS accuracy information, head to GPS.gov's website. That website also includes data and information on WAAS-enabled systems and accuracy levels depending on location. It's a great resource.
Basically, you can't get 2 meter accuracy reliably without some form of correction."

Here's a good site for GPS accuracy info

as I said I would be good to survey 15 feet from last coordinates but I've done that and I know that the GPS can get really messed up in a crash scenario. ie read my previous reply