Premium
The relative accuracy of ionogram analysis techniques
Author(s) -
Titheridge J. E.
Publication year - 1975
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs010i006p00589
Subject(s) - interpolation (computer graphics) , polynomial , polynomial interpolation , ionogram , mathematics , boundary (topology) , spline interpolation , spline (mechanical) , algorithm , linear interpolation , mathematical analysis , computer science , statistics , physics , animation , computer graphics (images) , electron density , quantum mechanics , bilinear interpolation , thermodynamics , electron
Increasing accuracy in the conversion of h ′( f ) to N ( h ) profiles is obtained by increasing the order of the polynomial used to interpolate between measured points. Linear and parabolic lamination techniques correspond to first‐ and second‐order interpolation. Fourth‐order interpolation (as in the 5‐term overlapping polynomial method) is about optimum. In comparing different methods, it is essential that fixed boundary conditions be employed; when this is done an adjacent polynomial technique is much less accurate than overlapping polynomials. All methods (including least‐squares procedures) are equally sensitive to errors in the virtual height data. Possible procedures for reducing the errors caused by underlying and valley ionization are critically reviewed. It is concluded that, in general, only a single parameter is necessary or desirable to describe these regions. This parameter can be determined from ordinary and extraordinary ray measurements, at any latitude.