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Titel |
Application of the locality principle to radio occultation studies of the Earth's atmosphere and ionosphere |
VerfasserIn |
A. G. Pavelyev, Y. A. Liou, S. S. Matyugov, A. A. Pavelyev, V. N. Gubenko, K. Zhang, Y. Kuleshov |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1867-1381
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 8, no. 7 ; Nr. 8, no. 7 (2015-07-17), S.2885-2899 |
Datensatznummer |
250116486
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Publikation (Nr.) |
copernicus.org/amt-8-2885-2015.pdf |
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Zusammenfassung |
A new formulation of the previously introduced principle of locality is
presented. The principle can be applied for modernization of the radio
occultation (RO) remote sensing of the atmospheres and ionospheres of the
Earth and other planets. The principle states that significant contributions to
variations of the intensity and phase of the radio waves passing through a
layered medium are connected with influence of the vicinities of tangential
points where the refractivity gradient is perpendicular to the radio ray
trajectory. The RO method assumes spherical symmetry of the investigated
medium. In this case, if location of a tangent point relative to the
spherical symmetry centre is known, the time derivatives of the RO signal
phase and Doppler frequency variations can be recalculated into the
refractive attenuation. Several important findings are consequences of the
locality principle: (i) if position of the centre of symmetry is known, the
total absorption along the ray path can be determined at a single frequency;
(ii) in the case of low absorption the height, displacement from the radio
ray perigee, and tilt of the inclined ionospheric (atmospheric) layers can
be evaluated; (iii) the contributions of the layered and irregular
structures in the RO signal can be separated and parameters of layers and
turbulence can be measured at a single frequency using joint analysis
of the intensity and phase variations. Specially for the Earth's
troposphere, the altitude distributions of the weak total absorption (about
of 1–4 db) of the radio waves at GPS frequencies corresponding to possible
influence of the oxygen, water vapour, and hydrometeors can be measured with
accuracy of about 0.1 db at a single frequency. In accordance with the locality
principle, a new index of ionospheric activity is introduced. This index is
measured from the phase variations of radio waves passing through the
ionosphere. Its high correlation with the S4 scintillation index is
established. This correlation indicates the significant influence of locally
spherical symmetric ionospheric layers on variations of the phase and
intensity of the RO signal passing through transionospheric communication
links. Obtained results expand applicable domain of the RO method as a
powerful remote sensing technique for geophysical and meteorological
research. |
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