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Termes IGN > sciences naturelles > physique > optique > optique physique > radiométrie > rayonnement électromagnétique > propagation ionosphérique
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Direction-of-arrival estimation of VHF signals recorded on the international space station and simultaneous observations of optical lightning / Hiroshi Kikuchi in IEEE Transactions on geoscience and remote sensing, vol 54 n° 7 (July 2016)
[article]
Titre : Direction-of-arrival estimation of VHF signals recorded on the international space station and simultaneous observations of optical lightning Type de document : Article/Communication Auteurs : Hiroshi Kikuchi, Auteur ; Takeshi Morimoto, Auteur ; Mitsuteru Sato, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 3868 - 3877 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] interférométrie
[Termes IGN] onde métrique
[Termes IGN] orage
[Termes IGN] positionnement absolu
[Termes IGN] propagation ionosphérique
[Termes IGN] radiomètre à hyperfréquence
[Termes IGN] rayonnement électromagnétiqueRésumé : (Auteur) We report an initial investigation of the new location method of a very high frequency (VHF) radiation source, using signals recorded at the International Space Station. A VHF interferometer (VITF) has two VHF sensors. Locating lightning with VHF bands is useful to locate the position of the charge distribution in the thunderstorm. The location method of a radio source proposed used two direction-of-arrival estimation techniques. One is the interferometric technique, and another is based on the ionospheric propagation delay measurement of received signals. The combination of the two techniques provides two angular positions of the radiation source. When an altitude of a radiation source is assumed, we can determine two possible positions. One of the two positions was associated with the radiation source, while the other was not. In this paper, we compared the position of lightning and sprite imager (LSI) data, which are simultaneously captured during a lightning emission, with the locating position near the emission. The data set of the VITF within 100 ms of the optical lightning emission captured with the LSI was used. The temporally simultaneous event seems to be associated with the same lightning event. The estimated radiation positions were spatially in close agreement with the optical lightning positions captured with LSI, under nighttime ionosphere conditions. From statistical analysis, the spatial difference of the standard deviation changed from 15.3 to 30.8 km depending on the installation direction of the VHF sensors. The usefulness and limitations of the method are also discussed. Numéro de notice : A2016-874 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2529658 En ligne : http://dx.doi.org/10.1109/TGRS.2016.2529658 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83033
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 7 (July 2016) . - pp 3868 - 3877[article]Characterization of ionospheric variability in TEC using EOF and wavelets over low-latitude GNSS stations / J.R.K. Kumar Dabbakuti in Advances in space research, vol 57 n° 12 (June 2016)
[article]
Titre : Characterization of ionospheric variability in TEC using EOF and wavelets over low-latitude GNSS stations Type de document : Article/Communication Auteurs : J.R.K. Kumar Dabbakuti, Auteur ; D. Venkata Ratman, Auteur Année de publication : 2016 Article en page(s) : pp 2427 – 2443 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] coordonnées GPS
[Termes IGN] fonction orthogonale
[Termes IGN] International Reference Ionosphere
[Termes IGN] retard ionosphèrique
[Termes IGN] teneur totale en électrons
[Termes IGN] transformation en ondelettesRésumé : (auteur) Investigation of ionospheric variability is essential for improving the daily ionospheric modeling and forecasting services of Global Navigation Satellite System (GNSS) applications. As India is a low-latitude region, more care has to be taken here to characterize the ionosphere due to irregularities and Equatorial Ionization Anomaly (EIA) conditions. Therefore, an appropriate method is required to diagnose the ionospheric variations during geomagnetic, solar and other disturbances. In this paper, the temporal ionospheric time delay variations were studied based on the Empirical Orthogonal Function (EOF) analysis and wavelet transforms (WT).These analyses were carried out with Total Electron Content (TEC) datasets obtained from three GNSS stations located in low-latitude regions. EOF analysis was performed on the TEC datasets, which were decomposed into a time series of orthogonal eigen values (or base functions) and associated coefficients. EOF base functions and their associated coefficients signify the hourly time variations and the day of the year variations. The results reveal that the first few EOFs represented the majority of TEC variability pertaining to the physical processes of the ionosphere. The accuracy of the EOF model was validated by the evaluation of observational TEC data with International Reference Ionosphere (IRI) 2012 models. The EOF model coefficients for each GNSS station showed a strong correlation with the IRI models and also described the correlation between the impacts of the level of geomagnetic activity on the ionosphere. The correlation coefficients for the first three EOFs were more than 0.95. The phase relationship of ionospheric TEC anomalies, with respect to the geomagnetic indices (Dst), were analyzed by wavelet transforms. Numéro de notice : A2016-267 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2016.03.029 En ligne : https://doi.org/10.1016/j.asr.2016.03.029 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80802
in Advances in space research > vol 57 n° 12 (June 2016) . - pp 2427 – 2443[article]Determination of differential code biases with multi-GNSS observations / Ningbo Wang in Journal of geodesy, vol 90 n° 3 (March 2016)
[article]
Titre : Determination of differential code biases with multi-GNSS observations Type de document : Article/Communication Auteurs : Ningbo Wang, Auteur ; Yunbin Yuan, Auteur ; Zishen Li, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 209 - 228 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] code GNSS
[Termes IGN] erreur systématique
[Termes IGN] estimation de précision
[Termes IGN] retard ionosphèrique
[Termes IGN] teneur totale en électrons
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) In order to better understand the differential code biases (DCBs) of global navigation satellite system, the IGGDCB method is extended to estimate the intra- and inter-frequency biases of the global positioning system (GPS), GLONASS, BeiDou navigation satellite system (BDS), and Galileo based on observations collected by the multi-GNSS experiment (MGEX) of the international GNSS service (IGS). In the approach of IGGDCB, the local ionospheric total electronic content is modeled with generalized triangular series (GTS) function rather than using a global ionosphere model or a priori ionospheric information. The DCB estimated by the IGGDCB method is compared with the DCB products from the Center for Orbit Determination in Europe (CODE) and German Aerospace Center (DLR), as well as the broadcast timing group delay (TGD) parameters over a 2-year span (2013 and 2014). The results indicate that GPS and GLONASS intra-frequency biases obtained in this work show the same precision levels as those estimated by DLR (about 0.1 and 0.2–0.4 ns for the two constellations, respectively, with respect to the products of CODE). The precision levels of IGGDCB-based inter-frequency biases estimated over the 24-month period are about 0.29 ns for GPS, 0.56 ns for GLONASS, 0.36 ns for BDS, and 0.24 ns for Galileo, respectively. Here, the accuracies of GPS and GLONASS biases are assessed relative to the products of CODE, while those of BDS and Galileo are compared with the estimates of DLR. In addition, the monthly stability indices of IGGDCB-based DCBs are 0.11 (GPS), 0.18 (GLONASS), 0.17 (BDS), and 0.14 (Galileo) ns for the individual constellation. Numéro de notice : A2016-246 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0867-4 Date de publication en ligne : 11/11/2015 En ligne : https://doi.org/10.1007/s00190-015-0867-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80752
in Journal of geodesy > vol 90 n° 3 (March 2016) . - pp 209 - 228[article]An enhanced algorithm to estimate BDS satellite’s differential code biases / Chuang Shi in Journal of geodesy, vol 90 n° 2 (February 2016)
[article]
Titre : An enhanced algorithm to estimate BDS satellite’s differential code biases Type de document : Article/Communication Auteurs : Chuang Shi, Auteur ; Lei Fan, Auteur Année de publication : 2016 Article en page(s) : pp 161 - 177 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] analyse combinatoire (maths)
[Termes IGN] BeiDou
[Termes IGN] constellation BeiDou
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] propagation ionosphériqueRésumé : (auteur) This paper proposes an enhanced algorithm to estimate the differential code biases (DCB) on three frequencies of the BeiDou Navigation Satellite System (BDS) satellites. By forming ionospheric observables derived from uncombined precise point positioning and geometry-free linear combination of phase-smoothed range, satellite DCBs are determined together with ionospheric delay that is modeled at each individual station. Specifically, the DCB and ionospheric delay are estimated in a weighted least-squares estimator by considering the precision of ionospheric observables, and a misclosure constraint for different types of satellite DCBs is introduced. This algorithm was tested by GNSS data collected in November and December 2013 from 29 stations of Multi-GNSS Experiment (MGEX) and BeiDou Experimental Tracking Stations. Results show that the proposed algorithm is able to precisely estimate BDS satellite DCBs, where the mean value of day-to-day scattering is about 0.19 ns and the RMS of the difference with respect to MGEX DCB products is about 0.24 ns. In order to make comparison, an existing algorithm based on IGG: Institute of Geodesy and Geophysics, China (IGGDCB), is also used to process the same dataset. Results show that, the DCB difference between results from the enhanced algorithm and the DCB products from Center for Orbit Determination in Europe (CODE) and MGEX is reduced in average by 46 % for GPS satellites and 14 % for BDS satellites, when compared with DCB difference between the results of IGGDCB algorithm and the DCB products from CODE and MGEX. In addition, we find the day-to-day scattering of BDS IGSO satellites is obviously lower than that of GEO and MEO satellites, and a significant bias exists in daily DCB values of GEO satellites comparing with MGEX DCB product. This proposed algorithm also provides a new approach to estimate the satellite DCBs of multiple GNSS systems. Numéro de notice : A2016-018 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0863-8 Date de publication en ligne : 11/10/2015 En ligne : https://doi.org/10.1007/s00190-015-0863-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79509
in Journal of geodesy > vol 90 n° 2 (February 2016) . - pp 161 - 177[article]Ionospheric corrections for single-frequency tracking of GNSS satellites by VLBI based on co-located GNSS / Benjamin Männel in Journal of geodesy, vol 90 n° 2 (February 2016)
[article]
Titre : Ionospheric corrections for single-frequency tracking of GNSS satellites by VLBI based on co-located GNSS Type de document : Article/Communication Auteurs : Benjamin Männel, Auteur ; Markus Rothacher, Auteur Année de publication : 2016 Article en page(s) : pp 189-203 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] co-positionnement
[Termes IGN] correction ionosphérique
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement par ITGB
[Termes IGN] poursuite de satellite
[Termes IGN] propagation ionosphériqueRésumé : (auteur) Tracking L-band signals of GNSS satellites by radio telescopes became a new observation type in recent years and will be used to improve reference system realizations and links between Earth- and space-fixed frames. First successful test observations were done, with the drawback of being single-frequency only. In order to correct the ionospheric delay by using GNSS phase observations from co-located receivers, the L4R approach was developed. Based on residuals derived by a least-squares processing of the GNSS geometry-free linear combination corresponding corrections could be derived. As a first validation step L4R corrections were applied to GNSS L1 data analysis. Station coordinate repeatibilities at the 1-cm level were obtained for baselines of a few thousand kilometers. Comparing the derived delay corrections to VLBI ionospheric delays for quasars located in same directions, differences with a standard deviation of 2.2 TECU could be achieved. Numéro de notice : A2016-035 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0865-6 Date de publication en ligne : 27/10/2015 En ligne : https://doi.org/10.1007/s00190-015-0865-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79512
in Journal of geodesy > vol 90 n° 2 (February 2016) . - pp 189-203[article]PermalinkPermalinkEffectiveness of observation-domain sidereal filtering for GPS precise point positioning / Christopher Atkins in GPS solutions, vol 20 n° 1 (January 2016)PermalinkWide-area ionospheric delay model for GNSS users in middle- and low-magnetic-latitude regions / An-Lin Tao in GPS solutions, vol 20 n° 1 (January 2016)PermalinkNew data processing strategy for single frequency GPS deformation monitoring / S-Q. Huang in Survey review, vol 47 n° 344 (September 2015)PermalinkIonospheric effects in uncalibrated phase delay estimation and ambiguity-fixed PPP based on raw observable model / Shengfeng Gu in Journal of geodesy, vol 89 n° 5 (May 2015)PermalinkAn alternative ionospheric correction model for global navigation satellite systems / M.M. Hoque in Journal of geodesy, vol 89 n° 4 (April 2015)PermalinkEstimating ionospheric delay using GPS/Galileo signals in the E5 band / Olivier Julien in Inside GNSS, vol 10 n° 2 (March - April 2015)PermalinkAssessing and mitigating the effects of the ionospheric variability on DGPS / Duojie Weng in GPS solutions, vol 19 n° 1 (January 2015)PermalinkMeasuring deformations using SAR interferometry and GPS observables with geodetic accuracy: Application to Tokyo, Japan / Tamer Elgarbawi in ISPRS Journal of photogrammetry and remote sensing, vol 88 (February 2014)Permalink