ok so this has been bugging me since it happened this morning and i need to talk through it with people who get it. doing a lattice tower inspection, 200ft guyed comms tower, pretty routine stuff at this point. im maybe 15 feet off the structure doing a close visual on some corroded hardware near the top section when the drone just starts drifting. not a lot, but enough that my stomach dropped. switched to atti mode manually and got it back but it was sketchy for a second.

pretty sure it was compass interference from the steel. i know this is a known thing and honestly i should have done a compass cal farther away from the structure before flying close but i was being lazy and figured id done this tower before. the thing is the previous inspections were fine and nothing changed as far as i know. different time of year maybe? wind was low, no precipitation.

flying an M300 with a Zenmuse Z30 so its not like its some toy. has anyone had this happen consistently on certain tower types or is it just random? wondering if adding a second GPS antenna would actually help or if this is purely a compass issue that GPS wont solve anyway

GPS wont fix a compass problem, youre right about that. the M300 has dual IMU and compass but if both are getting saturated from that much steel at close range youre basically fighting the FC's assumptions about where it is in space. atti mode was the right call. i always switch to atti before i get within like 20 feet of any steel structure at this point, just habit. some guys fly full manual for close-in tower work but thats a whole other skill level

the seasonal thing is interesting actually ? ive heard the argument that temperature affects compass calibration drift but i dont have data on that. might just be that you got closer this time without realizing it

this is why i cant get fully comfortable with tower work yet. im still mostly doing residential roofing and the occaisonal water tower for a municipal client and even then i get nervous around anything metal. respect for doing lattice towers, that environment looks genuinely stressful in the videos ive seen. do you use any kind of tether system or is that not practical at 200ft