Total Electron Content
The Total Electron Content or TEC is a key parameter not only for ionospheric studies but also for the correction of ionospheric effects which degrade GNSS positioning accuracy. Indeed, the influence of the ionosphere on GNSS measurements depends on GNSS wave frequency and on Total Electron Content which is the integral of the electron concentration on the GNSS receiver-to-satellite path. It is measured in TEC Units (TECU): 1 TECU=1016 electrons m-2.
GPS dual frequency measurements can be used to reconstruct the Total Electron Content. Vertical TEC can be computed with an accuracy of 2-3 TECU.
SWANS provides users with real- time information on TEC measured in the following (GPS) stations: