The scale heights (Hm), F2-region thickness parameter (B0) used in IRI (Bilitza, 2001; Bilitza and Reinisch, 2008) and the F2 peak parameters (peak density NmF2 and its height hmF2) were derived from electron-density profiles obtained from the ionograms using the ARTIST program (Huang and Reinisch, 1996; Reinisch and Huang, 2001).
Most "experimental" 3-D coordinates for small molecules provided by the PDB are, in essence, theoretical models derived from fitting electron density produced by X-ray diffraction experiments to the presumed location of atoms that are part of a protein, a ligand (typically bound to the protein), and other moieties (ions, water molecules, etc).
The validity of these profiles is tested in two ways: (a) by assessing deviations of measured electron densities from corresponding model values, and (b) by comparing the observed riometer absorption with the simulated absorption values derived from model electron densities representative of observed absorption levels.
This paper discusses the behavior of ionospheric parameters that were obtained from electron density profiles derived from ionograms recorded at El Arenosillo (37.1°N, 353.2°E; Dip = 52; Modip = 45.5) during some intense geomagnetic storms.
This difference would be derived from higher absorbed electron density of the former, accessible to electron trapping.
Measurement of frequency dependence of the probe impedance, therefore, allows us to derive the electron density from the UHR frequency.
As derived below, the electron density within the crystal and the diffraction patterns are related by a simple mathematical method, the Fourier transform, which allows the density to be calculated relatively easily from the patterns.
The upper frequency bound of the HFA at 10 MHz, however, allows for the ability to derive the local electron density from UHR frequency even deep inside the plasmasphere.
It is derived from tapped density and fluff density.
