Table 1 Construction of the LEMI model.
From: Local empirical model of ionospheric plasma density derived from Digisonde measurements at Irkutsk
1. Calculation of the 27-day running medians of the ionospheric characteristics Pmed (LT, D, Y). |
2. Transformation of Pmed (LT, D, Y) to Pmed (LT, M, YS) at equal month steps using linear interpolation. |
3. Calculation of the two sets of model parameters, (a) low solar activity set P0(LT, M) and (b) slope of the linear dependence on F10.7, PD (LT, M), using the linear regression of Pmed (LT, M, F10.7) on 1-year running mean of F10.7. |
4. Calculation of the B-spline coefficients for P0 and PD sets with local time step ΔLT = 0.5 hour and month step ΔM = 1. |