Hi! i was out flying my spark earlier. There was barely any wind and pretty good flying conditions. After flying for a while at a pretty high altitude i noticed the drone started to fly more and more towards the ocean without me doing anything. I got a magnetic field interference error message and the drone kept drifting outwards. I then lost contact with the drone. After a while it seems like the drone did a RTH and came back, then i regained signal and was able to fly the drone back. I felt like i had to really fight to get it back but im not sure what made it act that way. (could it be really strong winds further up that i wasnt able to feel at the ground?) What im most curious about is what interferred with the drone. There are no powerlines and i cant figure out what made the interference. Anybody with a little more experience than me wanna take a look at the flight log and try to figure out what caused the interference?

https://www.phantomhelp.com/LogViewer/5EMD3W8HDIDFPTVVLM3H/

Thanks

Hello and good day M0rth. I am sorry for the trouble and thank you for reaching out. Have you tried to fly to a different location to see if the issue will still persist? With regards to the interference you have experienced on you previous flight, most of the cause of the interference would be any wireless signal that interfering signals from the remote controller to the said drone. For example, you have the DJI Spark, the aircraft itself used an Optimize wifi connection but still prone to any interference especially when flying in the Urban area. I hope you understand. Thank you for your support.

Hi,

You are so lucky, not loosing your Spark and fly her back in ATTI mode !!
My advice is to contact DJI and ask them to analyze you log and dat file.
IMO something wrong with your SPARK.

Interference at that height? do not think so. YAW error, Compass errors, Speed errors, IMU errors (in any order) will cause the SPARK to go into ATTI.So mayby mayby a wrongly calibrated compass/IMU....but IMO a "common" error for SPARK models.

What happend;
Start flight with 15 satellites and good reception,
On the spot gaining height to 174 meters where a short disconnect happend, for 4.7 no data written in the file (at 3m29s),
During the climb YAW inputs were given, (see chart)
At 5m 27s a YawErrorLarge, not on the screen visible,  
** IMU is getting confused and will switch off use of GPS signals.... / thus ATTI mode **
At 5m 29s SPARK into ATTI mode + warning on the screen "Magnetic Field Interference. Exit P-GPS Mode"
Still flying above takeoff spot, height 238 meter.
Spark starts to drif away, RC down input by you.
At 5m54s SPARK is 44 meters away now...little YAW syteering by you
No Pitch/Roll input, only down and some YAW, drifting more away
At 6m41 SPARK heading is home heading! height 188 meter
More yaw input, heading away from home heading...
At 6m26s 97 meters away and no lost connenction (height 173)
At 7m33s connection!  SPARK now at 66.8 meter. In ATTI with no connection AUTLAND will be executed, that`s why height is lower now
BUT HAPPILY 2 bars reception so SPARK in P-GPS for short moment, stopping the AUTOLAND.  if not your SPARK autolanded at sea....
Again Yaw errors so back in ATTI
Heading more/less to home now, FWD pitch and SPARK flying to home, see polar chart how you did it!
Last part flying at low height flying in OPTI, so stabilized for that part.

BTW see this https://forum.dji.com/thread-185412-1-1.html

Cheers
JJB

Thank you very much for the analysis JJB. I will calibrate the sensors and do a test flight in an open area away from the sea.

I've had trouble calibrating near the ocean as well this week while on vacation in Puerto Rico.  This has happened a few times on this trip, up until I lost the drone in the rainforest