Accuracy of GPS for car location

[Rerod]

Looked at the location of the car on the app and showed it was parked at a hotel. Ask wife about it and she says she was shopping at Costco. Costco is about 1/8 of a mile from Costco. What is the probability that there was a discrepancy between actual location and displayed location?

 

[gsmith123]

Oh no.

1/8 mile is 660 ft. Generally the GPS is more accurate than that, but there's enough factors* that could throw this off that off it's not conclusive evidence of exactly where the car was... It's probably too late but the dash cam footage would be an authoritative source.

(*Offhand, high buildings and mountains obscuring sky visibility will impact GPS, maybe the map data shown in app is not accurate even if the GPS fix is, GPS takes some time to acquire an accurate fix, parking garages will significantly impact accuracy, etc)

Also, is the 660 ft to the Costco building or to the edge of the parking lot? Or in other words if the car was parked at the extreme edge of the Costco parking lot (maybe it was busy or to avoid door dings) how far would it be away from the hotel parking lot?

 

[Rerod]

Thanks for the info. Not really convenient to park at the hotel to go to Costco.