Got it. Flat.
And this is what scares me.
I have several Pixhawk based quads, from tiny 250 FPV with Bulgarian Pixhawk clone and old MT3329 GPS module up to the largest one based on S1000 frame with NEO-M8N, all with different GPS units, including old Mediatek MT3329, MT3339, LEO-6H, NEO-7 and...