Dilution of Precision: Why GPS Fails

Your phone thinking you are in the middle of a lake is actually a geometry failure called Dilution

of Precision. We call it DOP, and it is the invisible score that determines if your location

is trash or perfect. You have specific scores for everything, like HDOP for horizontal map accuracy and

VDOP for your height. But the king is GDOP, which combines position and time errors

into one big reality check. Basically, if the satellites are bunched up too

close together, your DOP score skyrockets and your navigation fails. You need a low score

to stay on the road.