Presented by the NOAA/Space Weather Prediction Center

Difference from 10 day average indicating recent trend 2009 Nov 08 0100 - 0115 UTC

Updated: 2009 Nov 08 0128 UTC     Data from a total of 47  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.