Presented by the NOAA/Space Weather Prediction Center

Updated: 2008 Sep 17 2029 UTC     Data from a total of 81  real-time GPS stations from the CORS , GPS/Met, and IGS networks are used for these calculations.

US-TEC provides vertical TEC and slant path values of the line-of-sight electron content to the GPS satellites in view at the time. Note that TEC values in regions outside of the CONUS have no data and should be treated with caution. This ionospheric product is designed to estimate the signal delay for single and dual frequency GPS applications. US-TEC products are provided for today and yesterday, prior to yesterday please go to NGDC.