LAUSR

The rate of total electron contents (ROT) calculated from global navigation satellite system (GNSS) observables has mainly been used as a quantity that can be averaged into an ROT index (ROTI), which is unable to detect small-scale, fast-moving disturbances. In this study, we demonstrate that a unique signature on ROT time series can be used to estimate the horizontal velocity and dimension of the irregularities when GNSS signals propagate through ionospheric irregularities (IIs). This was achieved by estimating the time lags and durations of the signatures observed by an array of closely spaced GNSS receivers. We applied this ROT-based estimation method to a three-element GNSS receiver array yielding high-rate carrier phase measurements in Poker Flat, Alaska. The velocities were estimated with a precision of 10 m/s and 2° in speed and direction, respectively. In summary, this method can be used to better describe spatial and temporal distributions of IIs. Furthermore, such distributions can be used to project or predict ionospheric fluctuations for receivers located in the directions of the ionospheric disturbance drift.