GPS correction method comprising providing benchmark GPS devices located respectively at a priori known stationary benchmark points within respective geographical zones, the stationary benchmark points having corresponding benchmark GPS coordinates; providing a benchmark database storing data mapping the GPS devices to the benchmark GPS coordinates of their respective stationary benchmark points and their respective geographical zones; receiving first GPS coordinates associated to objects within the geographical zones and second GPS coordinates associated to the stationary benchmark points measured at a same time period, the first GPS coordinates being transmitted by the benchmark GPS devices and the second GPS coordinates being transmitted by GPS devices associated to the objects; and generating corrected GPS coordinates of the object by measuring a deviation between the benchmark GPS coordinates and the second GPS coordinates and using the deviation for correcting the first GPS coordinates. There is also provided a GPS correction system.