Although different in the way of work, SBAS (Satellite Based Augmentation System) in general can be said is that using satellite DGPS. Coverage area is much broader than the use DGPS ground station. There are several acknowledged for SBAS, that is WAAS (Wide Area Augmentation System), EGNOS (European Geostationary Navigation Overlay Service), and MSAS (Multi-functional Satellite Augmentation System). Managed by the U.S. WAAS, EGNOS by the European Union, and MSAS by Japan. All three systems are mutually compatible with one another, which means navigation devices can use one system, will be able to use the two other systems also. At this time only WAAS is already fully operational and can be enjoyed by the user navigation tools in the world. However, a DGPS ground station are functioning properly, can improve the accuracy exceeds / equals improvement can be achieved by SBAS.
In general, can be divided into two major parts, namely "real time (direct)" and "Post-processing (after the activity is completed)." The purpose of the 'real time' is a navigation tool that uses SBAS or DGPS signals when used directly. While the 'post processing' meant that the data collected by the navigation tools in the process of re-using data from the DGPS ground station. There are plenty of DGPS ground stations around the world can we use for this, both free and paid versions, even we can directly use it via the internet.
Although DGPS or SBAS can improve accuracy, but on condition that the emitted signal contains a correction to an area where we use the navigation tool. If it does not contain the correction data for the area, there will be no increase in accuracy.