Receivers tend to be built with augmentation systems. This uses a network of ground stations that measure the variation in the GPS signal and transmit correcti

Receivers tend to be built with augmentation systems. This uses a network of ground stations that measure the variation in the GPS signal and transmit corrections over an additional satellite. This helps the device account for atmospheric interference. https://en.wikipedia.org/wiki/Wide_Area_Augmentation_System https://en.wikipedia.org/wiki/Wide_Area_Augmentation_System