Differential GPS (DGPS) is an enhancement to the standard Global Positioning System (GPS) that improves location accuracy. It uses a network of fixed ground-based reference stations that receive GPS signals and calculate the difference between their known positions and the positions reported by the GPS satellites. This difference is then transmitted to nearby GPS receivers, allowing them to correct their own position data. By applying these corrections, DGPS can achieve accuracy levels of about 1 to 3 meters, compared to the typical 10 to 20 meters of standard GPS. This technology is widely used in various applications, including marine navigation, land surveying, and agriculture.