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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)
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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]Performance of real-time Precise Point Positioning using IGS real-time service / Mohamed Elsobeiey in GPS solutions, vol 20 n° 3 (July 2016)
[article]
Titre : Performance of real-time Precise Point Positioning using IGS real-time service Type de document : Article/Communication Auteurs : Mohamed Elsobeiey, Auteur ; Salim Al-Harbi, Auteur Année de publication : 2016 Article en page(s) : pp 565 - 571 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] correction du signal
[Termes IGN] horloge
[Termes IGN] international GPS service for geodynamics
[Termes IGN] orbite
[Termes IGN] positionnement ponctuel précis
[Termes IGN] temps réelRésumé : (Auteur) Until recently, the real-time IGS precise orbit and clock corrections were only available for the predicted part of the ultra-rapid solution. Whereas the accuracy of the ultra-rapid orbit is about 5 cm, the root mean square (RMS) of the respective satellite clock corrections is, unfortunately, about 3 ns (0.9 m). Hence, high accuracy Precise Point Positioning (PPP) applications can be achieved only in post-processing rather than in realtime. With the availability of the IGS real-time service (RTS), it becomes possible to obtain precise satellite orbit and satellite clock corrections in realtime with accuracy better than those of the ultra-rapid products. Recent research has shown that GPS IGS RTS products availability is at least 95 %, which makes it possible to perform real-time PPP with high accuracy. We study the performance of IGS RTS products in PPP by introducing a detailed description and analysis of IGS RTS products, describing the broadcasting of the IGS RTS orbit and clock corrections and their implementation as corrections to the broadcast ephemerides, and analyzing IGS RTS in PPP using several, randomly selected globally distributed IGS stations. It is shown that using IGS RTS products in real-time PPP can improve the solution RMS by about 50 % compared with the solution obtained from the predicted part of the IGS ultra-rapid products. Numéro de notice : A2016-635 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0467-z En ligne : http://dx.doi.org/10.1007/s10291-015-0467-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81837
in GPS solutions > vol 20 n° 3 (July 2016) . - pp 565 - 571[article]Recursive orthogonal projection-based simplex growing algorithm / Hsiao-Chi Li in IEEE Transactions on geoscience and remote sensing, vol 54 n° 7 (July 2016)
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Titre : Recursive orthogonal projection-based simplex growing algorithm Type de document : Article/Communication Auteurs : Hsiao-Chi Li, Auteur ; Chein-I Chang, Auteur Année de publication : 2016 Article en page(s) : pp 3780 - 3793 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] algorithme du simplexe
[Termes IGN] filtre de Kalman
[Termes IGN] géophysique
[Termes IGN] image hyperspectrale
[Termes IGN] projection orthogonaleRésumé : (Auteur) The simplex growing algorithm (SGA) has been widely used for finding endmembers. It can be considered as a sequential version of the well-known endmember finding algorithm, N-finder algorithm (N-FINDR), which finds endmembers one at a time by growing simplexes. However, one of the major hurdles for N-FINDR and SGA is the calculation of simplex volume (SV) which poses a great challenge in designing any algorithm using SV as a criterion for finding endmembers. This paper develops an orthogonal projection (OP)-based SGA (OP-SGA) which essentially resolves this computational issue. It converts the issue of calculating SV to calculating the OP on previously found simplexes without computing matrix determinants. Most importantly, a recursive Kalman filter-like OP-SGA, to be called recursive OP-SGA (ROP-SGA), can be also derived to ease computation. By virtue of ROP-SGA, several advantages and benefits in computational savings and hardware implementation can be gained for which N-FINDR and SGA do not have. Numéro de notice : A2016-871 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2527737 En ligne : http://dx.doi.org/10.1109/TGRS.2016.2527737 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83028
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 7 (July 2016) . - pp 3780 - 3793[article]Correction of atmospheric refraction geolocation error for high resolution optical satellite pushbroom images / Ming Yan in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 6 (June 2016)
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Titre : Correction of atmospheric refraction geolocation error for high resolution optical satellite pushbroom images Type de document : Article/Communication Auteurs : Ming Yan, Auteur ; Chengyi Wang, Auteur ; Jianglin Ma, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 427 - 435 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] correction atmosphérique
[Termes IGN] erreur de positionnement
[Termes IGN] géoréférencement direct
[Termes IGN] image à haute résolution
[Termes IGN] image DMC-3
[Termes IGN] image optique
[Termes IGN] image satellite
[Termes IGN] réfraction atmosphériqueRésumé : (Auteur) When an optical remote sensing satellite is imaging the Earth in-orbit, the propagation direction of the Line of Sight (LOS) will be changed because of atmospheric refraction. This will result in a geolocation deviation on the collinear rigorous geometric model for direct georeferencing, pushbroom images. To estimate and correct the atmospheric refraction geolocation error, the LOS vector tracking algorithm is introduced and a weighted mean algorithm is used to simplify the ISO standard atmospheric model into a troposphere and stratosphere, i.e., two layers spherical atmosphere. The simulation result shows the atmospheric refraction will introduce about 2 m and 7.5 m geometric displacement when the spacecraft is off-pointed view at 30 and 45 degree angle, respectively. For a state-of-the-art high resolution satellite, the atmospheric refraction displacement shall be corrected. The method has been practiced in the DMC3/TripleSat Constellation to remove the atmospheric refraction geolocation error without ground control points. Numéro de notice : A2016-441 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.82.6.427 En ligne : http://dx.doi.org/10.14358/PERS.82.6.427 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81346
in Photogrammetric Engineering & Remote Sensing, PERS > vol 82 n° 6 (June 2016) . - pp 427 - 435[article]Improving the quality of low-cost GPS receiver data for monitoring using spatial correlations / Li Zhang in Journal of applied geodesy, vol 10 n° 2 (June 2016)
[article]
Titre : Improving the quality of low-cost GPS receiver data for monitoring using spatial correlations Type de document : Article/Communication Auteurs : Li Zhang, Auteur ; Volker Schwieger, Auteur Année de publication : 2016 Article en page(s) : pp 119 - 129 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] correction du trajet multiple
[Termes IGN] corrélation automatique de points homologues
[Termes IGN] coût
[Termes IGN] récepteur GPS
[Termes IGN] récepteur monofréquence
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) The investigations on low-cost single frequency GPS receivers at the Institute of Engineering Geodesy (IIGS) show that u-blox LEA-6T GPS receivers combined with Trimble Bullet III GPS antennas containing self-constructed L1-optimized choke rings can already obtain an accuracy in the range of millimeters which meets the requirements of geodetic precise monitoring applications (see [27]). However, the quality (accuracy and reliability) of low-cost GPS receiver data, particularly in shadowing environment, should still be improved, since the multipath effects are the major error for the short baselines.
For this purpose, several adjoined stations with low-cost GPS receivers and antennas were set up next to the metal wall on the roof of the IIGS building and measured statically for several days. The time series of three-dimensional coordinates of the GPS receivers were analyzed. Spatial correlations between the adjoined stations, possibly caused by multipath effect, will be taken into account. The coordinates of one station can be corrected using the spatial correlations of the adjoined stations, so that the quality of the GPS measurements is improved.
The developed algorithms are based on the coordinates and the results will be delivered in near-real-time (in about 30 minutes), so that they are suitable for structural health monitoring applications.Numéro de notice : A2016-559 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2015-0022 En ligne : http://dx.doi.org/10.1515/jag-2015-0022 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81738
in Journal of applied geodesy > vol 10 n° 2 (June 2016) . - pp 119 - 129[article]Listening for RF noise : An analysis of pre-despreading GNSS interference detection techniques / Ali Jafarnia-Jahromi in Inside GNSS, vol 11 n° 3 (May - June 2016)PermalinkA systematic impact assessment of GRACE error correlation on data assimilation in hydrological models / Maike Schumacher in Journal of geodesy, vol 90 n° 6 (June 2016)PermalinkGNSS threat quantification in the United Kingdom in 2015 / Chaz Dixon in Navigation aérienne, maritime, spatiale, terrestre, vol 63 n° 250 (mai - août 2016)PermalinkTowards reliable velocities of permanent GNSS stations / Janusz Bogusz in Reports on geodesy and geoinformatics, vol 100 (May 2016)PermalinkAutonomous relative navigation / Shahram Moafipoor in GPS world, vol 27 n° 4 (April 2016)PermalinkBand-limited signal reconstruction from irregular samples with variable apertures / David G. Long in IEEE Transactions on geoscience and remote sensing, vol 54 n° 4 (April 2016)PermalinkChange detection between SAR images using a pointwise approach and graph theory / Minh-Tan Pham in IEEE Transactions on geoscience and remote sensing, vol 54 n° 4 (April 2016)PermalinkFlying safe : GNSS Robustness for Unmanned Aircraft Systems / Joshua Stubbs in GPS world, vol 27 n° 4 (April 2016)PermalinkPerformance analysis of triple-frequency ambiguity resolution with BeiDou observations / Xiaohong Zhang in GPS solutions, vol 20 n° 2 (April 2016)PermalinkA study on the dependency of GNSS pseudorange biases on correlator spacing / André Hauschild in GPS solutions, vol 20 n° 2 (April 2016)PermalinkCombined Architecture : Enhancing Multi-Dimensional Signal Quality in GNSS Receivers / Nunzia Giorgia Ferrara in Inside GNSS, vol 11 n° 2 (March - April 2016)PermalinkInvestigations on the influence of antenna near-field effects and satellite obstruction on the uncertainty of GNSS-based distance measurements / Florian Zimmermann in Journal of applied geodesy, vol 10 n° 1 (March 2016)PermalinkNoise simulation and correction in synthetic airborne TIR Data for mineral quantification / Christoph Hecker in IEEE Transactions on geoscience and remote sensing, vol 54 n° 3 (March 2016)PermalinkA penalized spline-based attitude model for high-resolution satellite imagery / Hongbo Pan in IEEE Transactions on geoscience and remote sensing, vol 54 n° 3 (March 2016)PermalinkTemporal MODIS data for identification of wheat crop using noise clustering soft classification approach / Priyadarshi Upadhyay in Geocarto international, vol 31 n° 3 - 4 (March - April 2016)PermalinkToward 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)PermalinkAntenna pilots UAV / Adrien Perkins in GPS world, vol 27 n° 2 (February 2016)PermalinkIonospheric 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)PermalinkAdaptive GPS/INS integration for relative navigation / Je Young Lee in GPS solutions, vol 20 n° 1 (January 2016)PermalinkPermalink