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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]A new method for specular and diffuse pseudorange multipath error extraction using wavelet analysis / Giovanni Pugliano in GPS solutions, vol 20 n° 3 (July 2016)
[article]
Titre : A new method for specular and diffuse pseudorange multipath error extraction using wavelet analysis Type de document : Article/Communication Auteurs : Giovanni Pugliano, Auteur ; Umberto Robustelli, Auteur ; Fabio Rossi, Auteur ; Raffaele Santamaria, Auteur Année de publication : 2016 Article en page(s) : pp 499 - 508 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Campanie (Italie)
[Termes IGN] correction du trajet multiple
[Termes IGN] mesurage de pseudo-distance
[Termes IGN] onde porteuse
[Termes IGN] réflexion spéculaire
[Termes IGN] transformation en ondelettes
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) Multipath remains one of the major challenges in Global Navigation Satellite System (GNSS) positioning because it is considered the dominant source of ranging errors, which can be classified into specular and diffuse types. We present a new method using wavelets to extract the pseudorange multipath in the time domain and breaking it down into the two components. The main idea is an analysis-reconstruction approach based on application of both continuous wavelet transform (CWT) and discrete wavelet transform (DWT). The proposed procedure involves the use of L1 code-minus-carrier (CMC) observable where higher-frequency terms are isolated as residuals. CMC residuals are analyzed by applying the CWT, and we propose the scalogram as a technique for discerning time–frequency variations of the multipath signal. Unlike Fourier transform, the potential of the CWT scalogram for examining the non-stationary and multifrequency nature of the multipath is confirmed as it simultaneously allows fine detection and time localization of the most representative frequencies of the signal. This interpretation of the CWT scalogram is relevant when choosing the levels of reconstruction with DWT, allowing accurate time domain extraction of both the specular and diffuse multipath. The performance and robustness of the method and its boundary applicability are assessed. The experiment was carried out using a receiver of Campania GNSS Network. The results are given in which specular multipath error is achieved using DWT level 7 approximation component and diffuse multipath error is achieved using DWT level 6 denoised detail component. Numéro de notice : A2016-634 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0458-0 En ligne : http://dx.doi.org/10.1007/s10291-015-0458-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81838
in GPS solutions > vol 20 n° 3 (July 2016) . - pp 499 - 508[article]Range imaging of E-region field-aligned irregularities by using a multifrequency technique : validation and initial results / Jenn-Shyong Chen in IEEE Transactions on geoscience and remote sensing, vol 54 n° 7 (July 2016)
[article]
Titre : Range imaging of E-region field-aligned irregularities by using a multifrequency technique : validation and initial results Type de document : Article/Communication Auteurs : Jenn-Shyong Chen, Auteur ; Yen-Hsyang Chu, Auteur ; Ching-Lun Su, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 3739 - 3749 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] étalonnage d'instrument
[Termes IGN] fréquence multiple
[Termes IGN] ionosphère
[Termes IGN] onde métrique
[Termes IGN] radar imageurRésumé : (Auteur) This paper reports the first use of a multifrequency range imaging (RIM) technique for observing E-region field-aligned irregularities (FAIs) in the midlatitude ionosphere. The Middle and Upper atmosphere Radar (MUR; 34.85°N, 136.10°E) was used to conduct experiments with five equally spaced frequencies between 46.25 and 46.75 MHz. Three types of RIM data were examined: data with 13-element binary Barker codes, with 16-element binary complementary codes, and without phase codes. Moreover, two calibration approaches were adopted to validate the applicability of the RIM technique, which functioned as intended. Excellent RIM performance such as the ability to resolve several striations in an echo region of FAIs was demonstrated. However, sidelobe echoes caused by pulse coding mechanisms were occasionally observed at altitudes above and below the source regions in the coded data. Therefore, a procedure was developed according to one of the calibration approaches to identify and remove such kind of sidelobe echoes, which was shown to be applicable for the complementary-coded data. In addition to FAIs, a thin plasma layer with a thickness of approximately 1 km was identified as being structured with some tilted finer structures, which could not be observed in the original intensity images with a range resolution of 600 m. Preliminary estimates of the Doppler velocities indicated that a wind shear effect could be the cause of such tilted finer structures. Numéro de notice : A2016-870 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2521702 En ligne : http://dx.doi.org/10.1109/TGRS.2016.2521702 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83027
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 7 (July 2016) . - pp 3739 - 3749[article]Toward operational compensation of ionospheric effects in SAR interferograms: the split-spectrum method / Giorgio Gomba in IEEE Transactions on geoscience and remote sensing, vol 54 n° 3 (March 2016)
[article]
Titre : Toward operational compensation of ionospheric effects in SAR interferograms: the split-spectrum method Type de document : Article/Communication Auteurs : Giorgio Gomba, Auteur ; Alessandro Parizzi, Auteur ; Francesco De Zan, Auteur Année de publication : 2016 Article en page(s) : pp 1446 - 1461 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] bande L
[Termes IGN] compensation
[Termes IGN] correction ionosphérique
[Termes IGN] image ALOS-PALSAR
[Termes IGN] image radar moirée
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] phase
[Termes IGN] relief
[Termes IGN] retard troposphériqueRésumé : (Auteur) The differential ionospheric path delay is a major error source in L-band interferograms. It is superimposed to topography and ground deformation signals, hindering the measurement of geophysical processes. In this paper, we proceed toward the realization of an operational processor to compensate the ionospheric effects in interferograms. The processor should be robust and accurate to meet the scientific requirements for the measurement of geophysical processes, and it should be applicable on a global scale. An implementation of the split-spectrum method, which will be one element of the processor, is presented in detail, and its performance is analyzed. The method is based on the dispersive nature of the ionosphere and separates the ionospheric component of the interferometric phase from the nondispersive component related to topography, ground motion, and tropospheric path delay. We tested the method using various Advanced Land Observing Satellite Phased-Array type L-band synthetic aperture radar interferometric pairs with different characteristics: high to low coherence, moving and nonmoving terrains, with and without topography, and different ionosphere states. Ionospheric errors of almost 1 m have been corrected to a centimeter or a millimeter level. The results show how the method is able to systematically compensate the ionospheric phase in interferograms, with the expected accuracy, and can therefore be a valid element of the operational processor. Numéro de notice : A2016-130 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2481079 En ligne : https://doi.org/10.1109/TGRS.2015.2481079 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80017
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 3 (March 2016) . - pp 1446 - 1461[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2016031 SL Revue Centre de documentation Revues en salle Disponible Is waveform worth it? A comparison of LiDAR approaches for vegetation and landscape characterization / Karen Anderson in Remote sensing in ecology and conservation, vol 2 n° 1 (February 2016)
[article]
Titre : Is waveform worth it? A comparison of LiDAR approaches for vegetation and landscape characterization Type de document : Article/Communication Auteurs : Karen Anderson, Auteur ; Steven Hancock, Auteur ; Mathias I. Disney, Auteur ; Kevin J. Gaston, Auteur Année de publication : 2016 Article en page(s) : pp 5 - 15 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] canopée
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] forêt
[Termes IGN] forme d'onde
[Termes IGN] sous-bois
[Termes IGN] sous-étageRésumé : (auteur) Light Detection and Ranging (LiDAR) systems are frequently used in ecological studies to measure vegetation canopy structure. Waveform LiDAR systems offer new capabilities for vegetation modelling by measuring the time-varying signal of the laser pulse as it illuminates different elements of the canopy, providing an opportunity to describe the 3D structure of vegetation canopies more fully. This article provides a comparison between waveform airborne laser scanning (ALS) data and discrete return ALS data, using terrestrial laser scanning (TLS) data as an independent validation. With reference to two urban landscape typologies, we demonstrate that discrete return ALS data provided more biased and less consistent measurements of woodland canopy height (in a 100% tree covered plot, height underestimation bias = 0.82 m; SD = 1.78 m) than waveform ALS data (height overestimation bias = 0.65 m; SD = 1.45 m). The same biases were found in suburban data (in a plot consisting of 100% hard targets e.g. roads and pavements), but discrete return ALS were more consistent here than waveform data (SD=0.57 m compared to waveform SD=0.76 m). Discrete return ALS data performed poorly in describing the canopy understorey, compared to waveform data. Our results also highlighted errors in discrete return ALS intensity, which were not present with waveform data. Waveform ALS data therefore offer an improved method for measuring the three-dimensional structure of vegetation systems, but carry a higher data processing cost. New toolkits for analysing waveform data will expedite future analysis and allow ecologists to exploit the information content of waveform LiDAR. Numéro de notice : A2016--166 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1002/rse2.8 En ligne : http://doi.org/10.1002/rse2.8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87172
in Remote sensing in ecology and conservation > vol 2 n° 1 (February 2016) . - pp 5 - 15[article]A wavelet-based echo detector for waveform LiDAR data / Cheng-Kai Wang in IEEE Transactions on geoscience and remote sensing, vol 54 n° 2 (February 2016)PermalinkEffectiveness of observation-domain sidereal filtering for GPS precise point positioning / Christopher Atkins in GPS solutions, vol 20 n° 1 (January 2016)PermalinkEntwicklung einer direkten Georeferenzierungseinheit zur Positions- und Orientierungbestimmung leichter UAVs in Eichzeit / Christian Eling (2016)PermalinkPermalinkRemote Sensing Observations of Continental Surfaces, ch. 6. Airborne lidar data processing / Clément Mallet (2016)PermalinkPermalinkA fast and accurate algorithm for high-frequency trans-ionospheric path length determination / Dudy D Wijaya in Journal of geodesy, vol 89 n° 12 (december 2015)PermalinkFusion of waveform LiDAR data and hyperspectral imagery for land cover classification / Hongzhou Wang in ISPRS Journal of photogrammetry and remote sensing, vol 108 (October 2015)PermalinkGetting There by Tuning In: Using HD Radio Signals for Navigation / Ananta Vidyarthi in GPS world, vol 26 n° 9 (September 2015)PermalinkSnow depth estimation based on multipath phase combination of GPS triple-frequency signals / Kegen Yu in IEEE Transactions on geoscience and remote sensing, vol 53 n° 9 (September 2015)Permalink