The Impact of Receiver‐Satellite Line‐of‐Sight Orientation on GNSS TEC Observations of TIDs Induced by GWs From Convective Sources

Abstract Total electron content (TEC) measurements recorded by a dense network of ground receivers tracking signals from Global Navigation Satellite System satellites provide a large number of data points and are one of the most effective methods for observing the horizontal characteristics of traveling ionospheric disturbances (TIDs). Conventionally, the receiver‐satellite line‐of‐sight (LOS) geometry of TEC measurements is not considered except for applying an elevation cut‐off angle to exclude measurements of high signal noise. However, as TEC is the total number of electrons spatially integrated along its LOS, its effectiveness in observing TIDs is heavily influenced by the LOS alignment with respect to the electron density perturbations. LOSs that pass through regions of both increased and decreased electron densities are ineffective at detecting the perturbations from ambient waves. This is because the opposite phases are canceled, yielding a TEC measurement that is not sensitive to the wave characteristic. In this paper, we investigate the effectiveness of different LOS azimuth orientations for TEC observations of concentric TIDs induced by gravity waves (GWs) generated by a tropospheric convective source over the Continental United States (CONUS). Results indicate that the observation and characterization of TIDs from GWs can be significantly improved by using only LOSs with certain azimuth angles.