Our drone mapping went haywire on a 12-acre site

Last Tuesday we were mapping a commercial lot in Austin for earthwork estimates. About 30 minutes in the drone started drifting like crazy and then just dropped the signal completely. I spent 2 hours walking the grid with a handheld GPS to get basic elevations. Turns out a nearby cell tower was causing interference we didn't catch on the preflight check. Has anyone else had luck with frequency scanners or different drones for sites with heavy RF?

2 comments

2 Comments

skyler_craig9d ago

...actually it might not have been the cell tower itself causing your issue. Cell towers usually operate in the 700MHz to 2.5GHz range for their actual cellular signals, and most drones use 2.4GHz or 5.8GHz for control and video. The tower's antennas are designed to broadcast sideways and slightly downward, so unless you were flying directly at one of the antennas (which you wouldn't be, since they're up high), the interference probably wasn't from that. More likely culprit could be a nearby weather radar or maybe even a high-power radio station, those can mess with GPS signals in a way that feels like "drifting" but is actually the satellite lock getting scrambled. A simple frequency scanner might help, but honestly I'd look closer at your preflight checklist and make sure you're checking for known RF sources in the area using something like the FAA's B4UFLY app or even just a quick Google search for local broadcast towers.

the_joseph8d ago

Wait, hold up, you're saying a weather radar can mess with GPS on a drone? That's wild, I had no idea. I always figured it was just the cell towers themselves causing the problems, you know? I had this one time my Mavic started acting all wonky near a big radio station, and I just assumed it was the tall buildings bouncing signals around. But GPS scrambling from a weather radar? That sounds like some next level tech interference I never even thought about. Makes me wonder how many times I've blamed the wrong thing for a sketchy flight. I'm definitely gonna start checking for those broadcast towers before I take off, thanks for the heads up.