Total electron content

Total electron content (TEC) is an important descriptive quantity for the ionosphere of the Earth.

[1] TEC is significant in determining the scintillation and group and phase delays of a radio wave through a medium.

The value of the constant is approximately κ ≈ 40.308193 m3·s−2;[4][5] the units can be expressed equivalently as m·m2·Hz2 to highlight the cancellation involved in yielding delays τ in meters, given f in Hz and TEC in m−2.

However, very small variations of 0.1-0.5 TEC units can be also extracted under the assumption of relatively constant observational biases.

[7] These ionospheric disturbances are primarily generated by gravity waves propagating upward from lower atmosphere.