Alien8
Senior Moment
- Location
- (A little bit north of) Cambridge
GPS works best with direct line-of-sight to the satellites. It may also track attenuated and reflected signals but the accuracy of the fix will be degraded. Whether a receiver works upside down will probably depend mostly on the mounting, orientation, and any shielding of the antenna, as well as on the sensitivity of the receiver. If you turn a GPS upside down you may find it still tracks satellites close to the horizon but it may have a harder time with those directly above, ie now underneath it, for the reasons described. A GPS may work ok in your pocket, it may work inside some buildings, but it won't be at its best.