K(Asm) and E indices are calculated according to algorithms published in papers:
- Nowozynski, K., Ernst, T. and Jankowski, J.,
1991. Adaptive smoothing method for computer derivation of K-indices,
Geophys. J. Int., 104, pp. 85-93.
- Reda, J. and Jankowski, J.,
2004. Three-hour activity index based on power spectra estimation,
Geophys. J. Int., 157, pp. 141-146.