A DGPS survey uses a Differential Global Positioning System (DGPS) to improve the accuracy of GPS measurements. DGPS is used in many fields, including construction, agriculture, and land surveying. DGPS is a method of improving the accuracy of your receiver by adding a local reference station to augment the information available from the satellites. It also improves the integrity of the whole GPS system by identifying certain errors. Since the base station is fixed, we can use the difference between the measurement of the base and the rover receivers to create an error correction vector.