Mean ROTI is presented for the preceding minute for the European region.
The Rate of TEC index (ROTI) is defined as standard deviation of the rate of TEC (ROT) assuming the ionosphere as a thin layer. Hence the index provides information about temporal ionospheric irregularities. DLR’s ROTI is calculated for the European region between 25°N – 75°N and 20°W – 45°E. As input GPS dual-frequency data is acquired from different providers, like IGS and EUREF, in real-time via the German Federal Agency for Cartography and Geodesy in Frankfurt. These data is used to calculate relative TEC as input for the ROTI processing. The standard deviation is calculated over a one minute window and the ROT is calculated each second.
The ROTI measurements are mapped into a regular grid (2°x2° lat/lon). Each grid cell presents the mean of the ROTI measurements located in this cell.