Ionospheric mapping by computer contouring techniques

Perspectives on updated foF2 maps for IRI

“…Attention would need to be paid to scale sizes within the constraints of available data and to whether specific reference epochs or ongoing time-frames should be used. There are established numerical analysis techniques for generating grid values from irregularly geographically disposed data sets, including specifically the techniques of inverse-distance power law smoothing, minimum curvature smoothing and kriging (Samardjiev et al, 1993) that merit examination.…”

“…Alternatively, these differences may to some extent be Ôsmoothed outÕ by procedures which yield Ômore reasonableÕ contours. The underlying questions are: Ôover what distance from a measurement location should the measured values be supposed to influence the mapping?Õ and Ôcan a means be found to generate meaningful artificial Ôscreen-pointÕ values to aid the mapping in other areas?Õ The kriging technique (Samardjiev et al, 1993) has usefully been applied to allow for spatial correlation effects in which all the measurement data set over the whole mapping area are treated as homogenous and used to derive a mean correlagram showing how the correlation coefficient falls with distance separation. Following Rush and Edwards (1976), who demonstrated that correlation distance is typically halved between points displaced in latitude rather than longitude, Stanislawska et al (1996Stanislawska et al ( , 2000 have developed a kriging mapping technique (PLES) in which a latitude co-ordinate transformation is first applied, and which has been adopted by COST251 (Hanbaba, 1999).…”

Retarded lower trace on satellite ionograms as new means for studies of the ionospheric macro-irregularities

“…Introducing the parameters of these irregularities into the model should improve its predictive validity. If such data are available in the operation mode, then they can be used very efficiently in radio-communication practice [5] in the short-wavelength range.…”

Forecasting total electron content maps by neural network technique

“…Mapping carried out by using a certain method extrapolates the known discrete values continuously to the whole surface. There are various widely used ionospheric mapping techniques using both the ionosonde‐derived TEC and the GPS‐TEC [ Samardjiev et al , 1993; Cander , 2003; Jakowski et al , 2004; Stamper et al , 2004; Zolesi et al , 2004]. Samardjiev et al [1993] used contouring techniques for ionospheric mapping including Kriging technique, which performs best when compared with inverse distance squared technique and minimum curvature technique.…”

“…There are various widely used ionospheric mapping techniques using both the ionosonde‐derived TEC and the GPS‐TEC [ Samardjiev et al , 1993; Cander , 2003; Jakowski et al , 2004; Stamper et al , 2004; Zolesi et al , 2004]. Samardjiev et al [1993] used contouring techniques for ionospheric mapping including Kriging technique, which performs best when compared with inverse distance squared technique and minimum curvature technique. Cander [2003] discussed the findings of the European Union Action COST 251 and plans for the COST 271 on TEC forecast and mapping.…”