Satellite in situ measurements of plasma ( electron) density fluctuations provide direct information about the structure and morphology of irregularities that are responsible for scintillation of radio waves on transionospheric links. When supplemented with the ionosphere model and irregularity anisotropy model, they can be applied to model morphology of scintillation provided a suitable propagation model is used. In this paper we present a scintillation climatological model for the Northern Hemisphere high-latitude ionosphere, which makes use of the Dynamics Explorer 2 retarding potential analyzer plasma density data, IRI ionosphere model, and the phase screen propagation model. An important aspect of our work is that we derived from the satellite data not just the turbulence strength parameter C-s but also the spectral index p, which influences the scintillation level as well. We discuss the magnetic activity, season, magnetic time, and latitude dependence of these parameters. We were able to reproduce successfully the observed scintillation intensity diurnal and seasonal variations. The model satisfactorily describes the expansion of the scintillation zone under magnetically disturbed conditions and reproduces the dawn-dusk asymmetry in the scintillation intensity. The results demonstrate the usefulness of the proposed approach.
Scintillation modelling using in situ data
Materassi M
2007
Abstract
Satellite in situ measurements of plasma ( electron) density fluctuations provide direct information about the structure and morphology of irregularities that are responsible for scintillation of radio waves on transionospheric links. When supplemented with the ionosphere model and irregularity anisotropy model, they can be applied to model morphology of scintillation provided a suitable propagation model is used. In this paper we present a scintillation climatological model for the Northern Hemisphere high-latitude ionosphere, which makes use of the Dynamics Explorer 2 retarding potential analyzer plasma density data, IRI ionosphere model, and the phase screen propagation model. An important aspect of our work is that we derived from the satellite data not just the turbulence strength parameter C-s but also the spectral index p, which influences the scintillation level as well. We discuss the magnetic activity, season, magnetic time, and latitude dependence of these parameters. We were able to reproduce successfully the observed scintillation intensity diurnal and seasonal variations. The model satisfactorily describes the expansion of the scintillation zone under magnetically disturbed conditions and reproduces the dawn-dusk asymmetry in the scintillation intensity. The results demonstrate the usefulness of the proposed approach.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.