DGPSjärjestelmiä

DGPSjärjestelmiä, or Differential GPS, is a system that enhances the accuracy of standard Global Positioning System (GPS) signals. It achieves this by using a network of fixed ground-based reference stations. These reference stations are precisely located and continuously monitor GPS satellites. By comparing the expected GPS signal from a satellite with the actual signal received, the reference station can calculate an error correction value.

This error correction data is then broadcast to nearby GPS receivers, which are often referred to as "user receivers." When a user receiver receives this correction data, it can apply it to its own GPS measurements. This process effectively removes or significantly reduces the errors caused by atmospheric disturbances, satellite clock inaccuracies, and orbital variations that affect standard GPS signals.

The result is a substantial improvement in positional accuracy, often reducing errors from several meters to less than a meter, and in some advanced implementations, to centimeter-level precision. DGPS systems are crucial for applications requiring high accuracy, such as precision agriculture, maritime navigation, surveying, and construction. Different types of DGPS systems exist, including wide-area augmentation systems (WAAS) in North America, EGNOS in Europe, and MSAS in Japan, which provide these corrections over large geographical areas.