[lxgr]

Oh, wow, I didn't realize "Find my" worked even when both devices are offline! But it makes sense – all that's really needed is GPS and Bluetooth.

Were you able to access it right there without signal, or did you need to move to an area with coverage for it to sync?

[oldbbsnickname]

Not really. The phone only appears "off" but is in-fact in a low power mode providing beacons. It won't work if the battery were removed.

Also, modern iPhones use tower-assisted GNSS (GPS, GLONASS, Galileo, QZSS, BeiDou, and NavIC) so the satellite isn't necessarily Navistar. With fewer or no towers, and positioned in an odd orientation on the ground, a good fix becomes much less likely, and the range can increase from <1m to 10's-100's of m.

[lxgr]

> Not really. The phone only appears "off" but is in-fact in a low power mode providing beacons. It won't work if the battery were removed.

Sure, how else would it work? But people usually don’t disassemble their phone before losing it on a train/in a taxi etc.

> modern iPhones use tower-assisted GNSS

Yes, but GP says they didn’t have cell coverage where they lost it, so that wouldn’t help.