STL3 (IL)

STL3 is a continuously operating GNSS reference station in Saint Clair County, operated by NOAA's National Geodetic Survey as part of the NGS CORS network. The station tracks GPS and GLONASS constellations, providing real-time RTK corrections and archival data for static post-processing and network adjustments. Surveyors can utilize STL3 for precise positioning, baseline establishment, and quality