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Generating GPS satellite fractional cycle bias for ambiguity-fixed precise point positioning / Pan Li in GPS solutions, vol 20 n° 4 (October 2016)
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Titre : Generating GPS satellite fractional cycle bias for ambiguity-fixed precise point positioning Type de document : Article/Communication Auteurs : Pan Li, Auteur ; Xiaohong Zhang, Auteur ; Xiaodong Ren, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 771 - 782 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] données GRACE
[Termes IGN] erreur systématique
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïtéRésumé : (Auteur) With the development of precise point positioning (PPP), the School of Geodesy and Geomatics (SGG) at Wuhan University is now routinely producing GPS satellite fractional cycle bias (FCB) products with open access for worldwide PPP users to conduct ambiguity-fixed PPP solution. We provide a brief theoretical background of PPP and present the strategies and models to compute the FCB products. The practical realization of the two-step (wide-lane and narrow-lane) FCB estimation scheme is described in detail. With GPS measurements taken in various situations, i.e., static, dynamic, and on low earth orbit (LEO) satellites, the quality of FCB estimation and the effectiveness of PPP ambiguity resolution (AR) are evaluated. The comparison with CNES FCBs indicated that our FCBs had a good consistency with the CNES ones. For wide-lane FCB, almost all the differences of the two products were within ±0.05 cycles. For narrow-lane FCB, 87.8 % of the differences were located between ±0.05 cycles, and 97.4 % of them were located between ±0.075 cycles. The experimental results showed that, compared with conventional ambiguity-float PPP, the averaged position RMS of static PPP can be improved from (3.6, 1.4, 3.6) to (2.0, 1.0, 2.7) centimeters for ambiguity-fixed PPP. The average accuracy improvement in the east, north, and up components reached 44.4, 28.6, and 25.0 %, respectively. A kinematic, ambiguity-fixed PPP test with observation of 80 min achieved a position accuracy of better than 5 cm at the one-sigma level in all three coordinate components. Compared with the results of ambiguity-float, kinematic PPP, the positioning biases of ambiguity-fixed PPP were improved by about 78.2, 20.8, and 65.1 % in east, north, and up. The RMS of LEO PPP test was improved by about 23.0, 37.0, and 43.0 % for GRACE-A and GRACE-B in radial, tangential, and normal directions when AR was applied to the same data set. These results demonstrated that the SGG FCB products can be produced with high quality for users anywhere around the world to carry out ambiguity-fixed PPP solutions. Numéro de notice : A2016--029 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0483-z En ligne : http://dx.doi.org/10.1007/s10291-015-0483-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83931
in GPS solutions > vol 20 n° 4 (October 2016) . - pp 771 - 782[article]A mixed weighted least squares and weighted total least squares adjustment method and its geodetic applications / Y. Zhou in Survey review, vol 48 n° 351 (October 2016)
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Titre : A mixed weighted least squares and weighted total least squares adjustment method and its geodetic applications Type de document : Article/Communication Auteurs : Y. Zhou, Auteur ; X. Fang, Auteur Année de publication : 2016 Article en page(s) : pp 421 - 429 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie
[Termes IGN] compensation par moindres carrés
[Termes IGN] méthode des moindres carrés
[Termes IGN] pondération
[Termes IGN] variableRésumé : (Auteur) A mixed weighted least squares (WLS) and weighted total least squares (WTLS) (mixed WLS–WTLS) method is presented for an errors-in-variables (EIV) model with some fixed columns in the design matrix. The numerical computational scheme and an approximate accuracy assessment method are also provided. It is extended from the mixed Least squares (LS)–Total least squares (TLS) method to deal with the case that the random columns are corrupted by heteroscedastic correlated noises. The mixed WLS–WTLS method can improve the computational efficiency compared with the existing WTLS methods without loss of accuracy, particularly when the fixed columns are far more than random ones. The Bursa transformation and parallel lines fitting examples are carried out to demonstrate the performance of the proposed algorithm. Since the mixed WLS–WTLS problem includes both the WLS and the WTLS problem, it will have a more wide range of applications. Numéro de notice : A2016-823 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000040 En ligne : https://doi.org/10.1179/1752270615Y.0000000040 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82639
in Survey review > vol 48 n° 351 (October 2016) . - pp 421 - 429[article]Modeling the effects of horizontal positional error on classification accuracy statistics / Henry B. Glick in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 10 (October 2016)
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Titre : Modeling the effects of horizontal positional error on classification accuracy statistics Type de document : Article/Communication Auteurs : Henry B. Glick, Auteur ; Devin Routh, Auteur ; Charlie Bettigole, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 789 - 802 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] classification
[Termes IGN] erreur de positionnement
[Termes IGN] méthode de Monte-Carlo
[Termes IGN] simulationRésumé : (Auteur) Using a concept proposed by Stehman and Czaplewski (1997), we implemented spatially-explicit Monte Carlo simulations to test the effects of manually introduced horizontal positional error on standard inter-rater statistics derived from twelve classified high-resolution images. Through simulations we found that both overall and kappa accuracies decrease markedly with increasing error distance, varying greatly across distances relevant to practical application. The use of ground reference sites falling solely in homogeneous patches significantly improves inter-rater statistics and calls into question the use of kernel-smoothed data in one-time accuracy assessments. Our simulations offer insight into the scale of both structural and cover type heterogeneity across our landscapes, and support a new method for minimizing the effects of positional error on map accuracy. We recommend that analysts use caution when applying traditional accuracy assessment strategies to categorical maps, particularly when working with high-resolution imagery. Numéro de notice : A2016-934 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.82.10.789 En ligne : http://dx.doi.org/10.14358/PERS.82.10.789 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83348
in Photogrammetric Engineering & Remote Sensing, PERS > vol 82 n° 10 (October 2016) . - pp 789 - 802[article]Outlier detection by using fault detection and isolation techniques in geodetic networks / U.M. Durdag in Survey review, vol 48 n° 351 (October 2016)
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Titre : Outlier detection by using fault detection and isolation techniques in geodetic networks Type de document : Article/Communication Auteurs : U.M. Durdag, Auteur ; S. Hekimoglu, Auteur ; B. Erdogan, Auteur Année de publication : 2016 Article en page(s) : pp 400 - 408 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] coordonnées GNSS
[Termes IGN] décomposition
[Termes IGN] données GNSS
[Termes IGN] méthode de Monte-Carlo
[Termes IGN] système de référence géodésique
[Termes IGN] valeur aberranteRésumé : (Auteur) Fault detection and isolation (FDI) techniques, which are called standard parity space approach (SPSA) and optimal parity vector approach (OPVA), have been presented in literature extensively for engineering sensor systems or sensor networks. This paper demonstrates the abilities of these approaches to detect and isolate outliers in geodetic networks. The ability to detect and isolate outliers has been measured by computing the mean success rate (MSR) for some given probability of significance levels. These approaches have been applied to a levelling network and a Global Navigation Satellite System (GNSS) network. Different matrix decomposition techniques have been used as an alternative way to the Potter algorithm, which is used in SPSA and OPVA. It has been proven that the abilities of FDI techniques, i.e. the MSRs of OPVA, increase with regard to the ones of SPSA in the levelling network and the GNSS network especially if the significance level α is chosen as 0.001 by using Monte–Carlo simulation. Numéro de notice : A2016-822 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000038 En ligne : https://doi.org/10.1179/1752270615Y.0000000038 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82638
in Survey review > vol 48 n° 351 (October 2016) . - pp 400 - 408[article]A probabilistic approach to detect mixed periodic patterns from moving object data / Jun Li in Geoinformatica, vol 20 n° 4 (October - December 2016)
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Titre : A probabilistic approach to detect mixed periodic patterns from moving object data Type de document : Article/Communication Auteurs : Jun Li, Auteur ; Jingjing Wang, Auteur ; Junfei Zhang, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 715 - 739 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] comportement
[Termes IGN] détection automatique
[Termes IGN] détection d'objet
[Termes IGN] estimation par noyau
[Termes IGN] objet mobile
[Termes IGN] séquence d'images
[Termes IGN] variable aléatoireRésumé : (Auteur) The prevalence of moving object data (MOD) brings new opportunities for behavior related research. Periodic behavior is one of the most important behaviors of moving objects. However, the existing methods of detecting periodicities assume a moving object either does not have any periodic behavior at all or just has a single periodic behavior in one place. Thus they are incapable of dealing with many real world situations whereby a moving object may have multiple periodic behaviors mixed together. Aiming at addressing this problem, this paper proposes a probabilistic periodicity detection method called MPDA. MPDA first identifies high dense regions by the kernel density method, then generates revisit time sequences based on the dense regions, and at last adopts a filter-refine paradigm to detect mixed periodicities. At the filter stage, candidate periods are identified by comparing the observed and reference distribution of revisit time intervals using the chi-square test, and at the refine stage, a periodic degree measure is defined to examine the significance of candidate periods to identify accurate periods existing in MOD. Synthetic datasets with various characteristics and two real world tracking datasets validate the effectiveness of MPDA under various scenarios. MPDA has the potential to play an important role in analyzing complicated behaviors of moving objects. Numéro de notice : A2016-814 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1007/s10707-016-0261-2 En ligne : http://dx.doi.org/10.1007/s10707-016-0261-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82615
in Geoinformatica > vol 20 n° 4 (October - December 2016) . - pp 715 - 739[article]Relative importance analysis of Landsat, waveform LIDAR and PALSAR inputs for deciduous biomass estimation / Alyssa Endres in European journal of remote sensing, vol 49 n° 1 (2016)
PermalinkQuantitative assessment of meteorological and tropospheric Zenith Hydrostatic Delay models / Di Zhang in Advances in space research, vol 58 n° 6 (September 2016)
PermalinkFinding spatial outliers in collective mobility patterns coupled with social ties / Monica Wachowicz in International journal of geographical information science IJGIS, vol 30 n° 9-10 (September - October 2016)
PermalinkIdentification of stable areas in unreferenced laser scans for deformation measurement / Daniel Wujanz in Photogrammetric record, vol 31 n° 155 (September - November 2016)
PermalinkPPP-RTK and inter-system biases: the ISB look-up table as a means to support multi-system PPP-RTK / Amir Khodabandeh in Journal of geodesy, vol 90 n° 9 (September 2016)
PermalinkA remark on the GNSS single difference model with common clock scheme for attitude determination / Wantong Chen in Journal of applied geodesy, vol 10 n° 3 (September 2016)
PermalinkTaking correlations in GPS least squares adjustments into account with a diagonal covariance matrix / Gaël Kermarrec in Journal of geodesy, vol 90 n° 9 (September 2016)
PermalinkUnderstanding the bias of call detail records in human mobility research / Ziliang Zhao in International journal of geographical information science IJGIS, vol 30 n° 9-10 (September - October 2016)
PermalinkVariance components estimation of residual errors in GPS precise positioning / Darko Anđić in Geodetski vestnik, vol 60 n° 3 (September - November 2016)
PermalinkAutomatic extraction of road networks from GPS traces / Jia Qiu in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 8 (August 2016)
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