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Refractive index of HPM at transionospheric propagation


Abstract: The characteristic of high power microwave(HPM) propagation through ionosphere is mainly determined by the diversification of the atmospheric refractive index,while the refractive index has positive correlation with the electron concentration at corresponding propagation layer.The critical frequency of ionosphere in linearity condition and the atmospheric refractive index formula are derived.The electron concentration and the atmospheric refractive index are numerically simulated based on ionospheric electron concentration distributing model.The diversification of the refractive index and the refractive index gradient relating to the altitude are also analyzed, and experiment has been taken under low power microwave condition which validates that the corrected value is closer to the practicality than the value operated from general theory.Hence the altitude,elevation and incept power of HPM propagation can be modified by the theory of this paper,which can also provide theoretic reference to practical HPM propagation.
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Journal ArticleDOI
Linan Yuan1, Jingjuan Liao1Institutions (1)
TL;DR: A modified physical-based method of LST retrieval from passive microwave data was developed for wide viewing zenith angles, and the LST and emissivity can be simultaneously estimated through the analysis of various atmospheric and ionosphere parameters.
Abstract: Land surface temperature (LST) is a key parameter and plays an important role in hydrology, ecology, environment, and biogeochemistry. It is difficult for the existing satellites to acquire global LST with spatial and temporal consistency. The Moon-based Earth observation platform with a long life, large coverage can observe continuously the Earth, and obtain the global-scale LST. At present, various approaches for retrieving LST from passive microwave remote sensing data have been developed for the satellite remote sensing data with small and constant viewing zenith angle, however, the Moon-based Earth observation platform located outside the Earth's ionosphere has the viewing zenith angle of 0–90°. In this study, a modified physical-based method of LST retrieval from passive microwave data was developed for wide viewing zenith angles, and the LST and emissivity can be simultaneously estimated through the analysis of various atmospheric and ionosphere parameters. Three types of data, including the FengYun-3B satellite microwave radiation imager data, the multichannel Advanced Microwave Scanning Radiometer data, and Moon-based microwave radiation simulation data with the viewing zenith angles of 52–53°, 55°, and 0–90°, respectively, were used to retrieve LST. Results show that the estimation accuracy of LST decreases with the increase of viewing zenith angle. The 23.8 and 36.5 GHz brightness temperature is optimum for the LST estimation under a large-scale viewing zenith angle, and the root mean square errors of the LST are 5.18, 5.44, and 4.79 K, respectively.

4 citations


Cites background from "Refractive index of HPM at transion..."

  • ...These electrons and ions will also cause the attenuation of incident microwave radiation energy due to their collisions in the ionosphere [43]–[48]....

    [...]


Journal ArticleDOI
Abstract: Stealth characteristic of two dimensional cylinder plasma envelopes is studied. Three cases about plasma refraction efiect, re∞ection characteristic and attenuation by absorbing electromagnetic wave (EMW) are concerned synthetically. As for plasma refraction stealth, EMW traces equation in cylinder plasma is deduced; a novel concept of plasma refraction deviation angle is presented; the relation between refraction deviation angle and incidence angle of EMW is yielded; the relation between refraction deviation angle and plasma density distribution is made out. As for re∞ection stealth and attenuation stealth, re∞ection calculation of multi-layer plasma is presented flrst, and plasma collision frequency as well as corresponding collision absorption is taken into account simultaneously, then EMW re∞ectivity with double-path attenuation is obtained. It is shown that cylinder plasma envelopes considering the three cases above could make distinct stealth.

15 citations


References
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Journal ArticleDOI
Linan Yuan1, Jingjuan Liao1Institutions (1)
TL;DR: A modified physical-based method of LST retrieval from passive microwave data was developed for wide viewing zenith angles, and the LST and emissivity can be simultaneously estimated through the analysis of various atmospheric and ionosphere parameters.
Abstract: Land surface temperature (LST) is a key parameter and plays an important role in hydrology, ecology, environment, and biogeochemistry. It is difficult for the existing satellites to acquire global LST with spatial and temporal consistency. The Moon-based Earth observation platform with a long life, large coverage can observe continuously the Earth, and obtain the global-scale LST. At present, various approaches for retrieving LST from passive microwave remote sensing data have been developed for the satellite remote sensing data with small and constant viewing zenith angle, however, the Moon-based Earth observation platform located outside the Earth's ionosphere has the viewing zenith angle of 0–90°. In this study, a modified physical-based method of LST retrieval from passive microwave data was developed for wide viewing zenith angles, and the LST and emissivity can be simultaneously estimated through the analysis of various atmospheric and ionosphere parameters. Three types of data, including the FengYun-3B satellite microwave radiation imager data, the multichannel Advanced Microwave Scanning Radiometer data, and Moon-based microwave radiation simulation data with the viewing zenith angles of 52–53°, 55°, and 0–90°, respectively, were used to retrieve LST. Results show that the estimation accuracy of LST decreases with the increase of viewing zenith angle. The 23.8 and 36.5 GHz brightness temperature is optimum for the LST estimation under a large-scale viewing zenith angle, and the root mean square errors of the LST are 5.18, 5.44, and 4.79 K, respectively.

4 citations


Journal ArticleDOI
Abstract: Stealth characteristic of two dimensional cylinder plasma envelopes is studied. Three cases about plasma refraction efiect, re∞ection characteristic and attenuation by absorbing electromagnetic wave (EMW) are concerned synthetically. As for plasma refraction stealth, EMW traces equation in cylinder plasma is deduced; a novel concept of plasma refraction deviation angle is presented; the relation between refraction deviation angle and incidence angle of EMW is yielded; the relation between refraction deviation angle and plasma density distribution is made out. As for re∞ection stealth and attenuation stealth, re∞ection calculation of multi-layer plasma is presented flrst, and plasma collision frequency as well as corresponding collision absorption is taken into account simultaneously, then EMW re∞ectivity with double-path attenuation is obtained. It is shown that cylinder plasma envelopes considering the three cases above could make distinct stealth.

15 citations


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20101