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Help with Mavic 2 Pro Crash Location

You're right. I was looking at the battery_info:wind_dir and assuming the usual DJI convention was being used.

I printed your graph and laid a straight edge on the North and East plots and there is a slight bend to those curves.

This shows computed velocity as a function of time. The horizontal velocities are asymptoting to the wind velocity, as expected.

Results2.png
 
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The DAT file also shows multiple battery error entries starting at 2 seconds:

2.080 : 1980 [L-BATTERY][ERROR] BATTERY_STATE_ABSENT​

but no other obvious clues that I can see. It looks like a power disconnect shut down. It has to be there.
I finally found it last night. Had searched 5 previous times with no luck and decided to take a break for a few weeks. Went back last night and couldn't believe it when I finally saw it.

It had become separated from the battery which was nowhere to be found in the immediate and surrounding vicinity. The drone was found at 41.5261 -122.3472. That was about 60-70 feet short of the projected landing spot, but possibly lacking the weight of the battery, I can understand why that would change.

Amazingly, the damage was not nearly what I expected for a drone falling 400ft out of the sky. It's actually completely intact and after installing a new battery it turns on and the gimbal works as normal. There is one motor that is frozen and one front landing gear is broken. I have refresh, so I'll be sending it in.

All in all a good ending with some lessons learned. Mainly, to get some sort of third party tracker. Looking for a downed drone is much more difficult than I ever imagined.

Thanks again to all who provided some insight on this situation.

Special thanks to sar104 for providing the crash estimate. That gave me the confidence to know it had to be there somewhere.
 

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I finally found it last night. Had searched 5 previous times with no luck and decided to take a break for a few weeks. Went back last night and couldn't believe it when I finally saw it.

It had become separated from the battery which was nowhere to be found in the immediate and surrounding vicinity. The drone was found at 41.5261 -122.3472. That was about 60-70 feet short of the projected landing spot, but possibly lacking the weight of the battery, I can understand why that would change.

Amazingly, the damage was not nearly what I expected for a drone falling 400ft out of the sky. It's actually completely intact and after installing a new battery it turns on and the gimbal works as normal. There is one motor that is frozen and one front landing gear is broken. I have refresh, so I'll be sending it in.

All in all a good ending with some lessons learned. Mainly, to get some sort of third party tracker. Looking for a downed drone is much more difficult than I ever imagined.

Thanks again to all who provided some insight on this situation.

Special thanks to sar104 for providing the crash estimate. That gave me the confidence to know it had to be there somewhere.
So glad you solved your mystery. And yes, SAR104 is amazing.
 
I finally found it last night. Had searched 5 previous times with no luck and decided to take a break for a few weeks. Went back last night and couldn't believe it when I finally saw it.

It had become separated from the battery which was nowhere to be found in the immediate and surrounding vicinity. The drone was found at 41.5261 -122.3472. That was about 60-70 feet short of the projected landing spot, but possibly lacking the weight of the battery, I can understand why that would change.

Amazingly, the damage was not nearly what I expected for a drone falling 400ft out of the sky. It's actually completely intact and after installing a new battery it turns on and the gimbal works as normal. There is one motor that is frozen and one front landing gear is broken. I have refresh, so I'll be sending it in.

All in all a good ending with some lessons learned. Mainly, to get some sort of third party tracker. Looking for a downed drone is much more difficult than I ever imagined.

Thanks again to all who provided some insight on this situation.

Special thanks to sar104 for providing the crash estimate. That gave me the confidence to know it had to be there somewhere.

Excellent news. And yes - that's actually 75 ft short of my estimate, which is more than I would have expected. If the battery had ejected I would actually have expected it to go further with the wind, due to the increased vertical drag, so that's a bit of a puzzle. Perseverance rewarded though. Nice work.
 
Excellent news. And yes - that's actually 75 ft short of my estimate, which is more than I would have expected. If the battery had ejected I would actually have expected it to go further with the wind, due to the increased vertical drag, so that's a bit of a puzzle. Perseverance rewarded though. Nice work.
If the battery ejected then it's possible the M2 achieved a nose down orientation and vertical drag actually decreased causing a more downward trajectory. But, then the horizontal force would increase due to the wind. Apparently, the vertical decrease was more than the horizontal increase.
 
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If the battery ejected then it's possible the M2 achieved a nose down orientation and vertical drag actually decreased causing a more downward trajectory. But, then the horizontal force would increase due to the wind. Apparently, the vertical decrease was more than the horizontal increase.

True. Or maybe my maths just sucks.
 
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True. Or maybe my maths just sucks.
Oh no. I'm sure your math is correct. Impeccable. Flawless. Of the highest order. Heard enough? :)

Kidding aside there is only so much that can be done without a better model based on empirical data. Knowing the wind field at different heights would also help.
 
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Oh no. I'm sure your math is correct. Impeccable. Flawless. Of the highest order. Heard enough? :)

Kidding aside there is only so much that can be done without a better model based on empirical data. Knowing the wind field at different heights would also help.

Agreed. On the data I mean. There is also the issue that the drag model I use is fitted to previous tumbling Mavic data, and could change if the attitude is not chaotic during the descent.
 
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