Here are some links to various VRS (Virtual Reference Stations). Some of them charge a seasonal or annual fee to obtain access, others are free of charge. For an explanation of what VRS networks are, click here.
Many states are now offering statewide or regional GNSS real time networks that allow the user to receive real time corrections to their survey or mapping rover. There are several requirements that must be met in order to receive these corrections:
Questions? Go to my Contact page for help.
GPS Education Resource
Your GNSS Training Headquarters for GIS and Mapping Applications