Ionospheric Disturbance Indices for RTK and Network RTK Positioning

Ionospheric disturbances may cause difficulties in singlebase RTK and even in Network RTK positioning. Hence, index values providing statistical information on expected residual ionospheric biases are of great help to RTK users. One such indicator is the I95 ionospheric disturbance index which has been in continuous use in Central Europe since 1998. This 7 year long time series contains valuable statistical information on the occurrence of medium-scale and small-scale ionospheric disturbances. Whereas the I95 index is mainly suited for RTK positioning, a newly developed I95L-index is aimed at Network RTK users. Numerical values of both indices are compared.