Testing the IONORT‐ISP system: A comparison between synthesized and measured oblique ionograms

Abstract

[1] The three-dimensional (3-D) electron density representation of the ionosphere computed by the assimilative IRI-SIRMUP-P (ISP) model was tested using IONORT (IONOspheric Ray-Tracing), a software tool for calculating a 3-D ray-tracing for highfrequency waves in the ionospheric medium. A radio link was established between Rome (41.8 N, 12.5 E) in Italy, and Chania (35.7 N, 24.0 E) in Greece, within the ISP validity area, and for which oblique soundings are conducted. The ionospheric reference stations, from which the autoscaled foF2 and M(3000)F2 data and real-time vertical electron density profiles were assimilated by the ISP model, were Rome (41.8 N, 12.5 E) and Gibilmanna (37.9 N, 14.0 E) in Italy, and Athens (38.0 N, 23.5 E) in Greece. IONORT was used, in conjunction with the ISP and the International Reference Ionosphere 3-D electron density grids, to synthesize oblique ionograms. The comparison between synthesized and measured oblique ionograms, both in terms of the ionogram shape and the maximum usable frequency characterizing the radio path, demonstrates both that the ISP model can more accurately represent real conditions in the ionosphere than the IRI, and that the raytracing results computed by IONORT are reasonably reliable.

Tomography of the ionospheric electron density with geostatistical inversion

“…Our goal is to enhance initialization of the background model by using the ionosonde F2 layer measurements, as well as the assimilation of ionosonde electron density profiles; see, e.g., Pezzopane et al (2013); Settimi et al (2013).…”

Scientific Review on the Ionospheric Absorption and Research Prospects of a Complex Eikonal Model for One-Layer Ionosphere

“…In order to solve the ionospheric ray-tracing and absorption problems, Settimi et al [11] have prospected a novel point of view. Equations (21a)-(21b) or (22) for complex eikonal are derived assuming the material medium as optically isotropic. However, there exist suitable conditions in which (21a)-(21b) or (22) can be referred to the Appleton-Hartree equations (5) or (6) for ionospheric magnetoplasma, which becomes anisotropic at the presence of geomagnetic field.…”

“…Equations (21a)-(21b) or (22) for complex eikonal are derived assuming the material medium as optically isotropic. However, there exist suitable conditions in which (21a)-(21b) or (22) can be referred to the Appleton-Hartree equations (5) or (6) for ionospheric magnetoplasma, which becomes anisotropic at the presence of geomagnetic field. Indeed, in agreement with [16][17][18], the quasi-isotropic approximation (QIA) of geometrical optics can be applied for weakly anisotropic inhomogeneous media, so that the eikonal equations hold alternatively for both the ordinary and extraordinary rays, which propagate independently in the magnetoplasma by experiencing each a different refractive index.…”

“…Inserting the refractive index (25a) to solve the real part ∇ = ( ⃗ )̂of complex eikonal equation (22), then the optical path ℎ = ℎ( ) is obtained [11] (Figure 1):…”

Empirical regional models for the short-term forecast of <i>M3000F2</i> during not quiet geomagnetic conditions over Europe

“…ionosphere in real time for quiet and disturbed geomagnetic conditions (Pezzopane et al, 2011 was developed and then used for calculating a 3-D ray tracing in the ionospheric medium on the base of measured oblique ionograms over a given radio link (Settimi et al, 2013).…”