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Testing deformation hypotheses by constraints on a time series of geodetic observations / Hiddo Velsink in Journal of applied geodesy, vol 12 n° 1 (January 2018)
[article]
Titre : Testing deformation hypotheses by constraints on a time series of geodetic observations Type de document : Article/Communication Auteurs : Hiddo Velsink, Auteur Année de publication : 2018 Article en page(s) : pp 77 - 94 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] compensation par moindres carrés
[Termes IGN] congruence
[Termes IGN] déformation géométrique
[Termes IGN] programmation par contraintes
[Termes IGN] série temporelleRésumé : (auteur) In geodetic deformation analysis observations are used to identify form and size changes of a geodetic network, representing objects on the earth’s surface. The network points are monitored, often continuously, because of suspected deformations. A deformation may affect many points during many epochs. The problem is that the best description of the deformation is, in general, unknown. To find it, different hypothesised deformation models have to be tested systematically for agreement with the observations. The tests have to be capable of stating with a certain probability the size of detectable deformations, and to be datum invariant. A statistical criterion is needed to find the best deformation model. Existing methods do not fulfil these requirements. Here we propose a method that formulates the different hypotheses as sets of constraints on the parameters of a least-squares adjustment model. The constraints can relate to subsets of epochs and to subsets of points, thus combining time series analysis and congruence model analysis. The constraints are formulated as nonstochastic observations in an adjustment model of observation equations. This gives an easy way to test the constraints and to get a quality description. The proposed method aims at providing a good discriminating method to find the best description of a deformation. The method is expected to improve the quality of geodetic deformation analysis. We demonstrate the method with an elaborate example. Numéro de notice : A2018-016 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2017-0028 En ligne : https://doi.org/10.1515/jag-2017-0028 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89095
in Journal of applied geodesy > vol 12 n° 1 (January 2018) . - pp 77 - 94[article]3D building model-assisted snapshot positioning algorithm / Rakesh Kumar in GPS solutions, vol 21 n° 4 (October 2017)
[article]
Titre : 3D building model-assisted snapshot positioning algorithm Type de document : Article/Communication Auteurs : Rakesh Kumar, Auteur ; Mark G. Petovello, Auteur Année de publication : 2017 Article en page(s) : pp 1923 - 1935 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] Calgary
[Termes IGN] compensation par moindres carrés
[Termes IGN] corrélateur
[Termes IGN] lancer de rayons
[Termes IGN] milieu urbain
[Termes IGN] modèle 3D de l'espace urbain
[Termes IGN] positionnement par GNSS
[Termes IGN] récepteur GNSS
[Termes IGN] résidu
[Termes IGN] trajet multipleRésumé : (Auteur) A method for constructively using non-line-of-sight GNSS signals from a snapshot of signal samples for positioning of users in urban areas is presented here. Using a 3D building model and a ray-tracing algorithm, the number of reception paths and the corresponding path delays of reflected signals are predicted, across a rid of candidate positions. These predictions are then used to compute a least squares fit to the GNSS receiver’s correlator outputs, and the position with smallest residuals is selected as the position estimate. Using data collected along 3.5 km of road in downtown Calgary, Canada, where buildings reach heights of over 200 m, the root-mean-square position error is below 10 m in the along-track and across-track directions. Compared to two pseudorange-based receivers, the proposed method yields RMS error improvements of at least 31% in the along-track direction, 63% in the across-track direction, and 53% in the horizontal plane. Numéro de notice : A2017-621 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-017-0661-2 En ligne : https://doi.org/10.1007/s10291-017-0661-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86931
in GPS solutions > vol 21 n° 4 (October 2017) . - pp 1923 - 1935[article]Bias compensation for rational function model based on total least squares / Anzhu Yu in Photogrammetric record, vol 32 n° 157 (March - May 2017)
[article]
Titre : Bias compensation for rational function model based on total least squares Type de document : Article/Communication Auteurs : Anzhu Yu, Auteur ; Ting Jiang, Auteur ; Wenyue Guo, Auteur Année de publication : 2017 Article en page(s) : pp 48 - 60 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] analyse numérique
[Termes IGN] calcul d'erreur
[Termes IGN] compensation par moindres carrés
[Termes IGN] erreur aléatoire
[Termes IGN] erreur systématique
[Termes IGN] modèle par fonctions rationnelles
[Termes IGN] pondération
[Termes IGN] précision du positionnementRésumé : (auteur) When using the rational function model for the geometric orientation and geopositioning of satellite imagery, systematic bias compensation for vendor-provided rational polynomial coefficients (RPCs) is very important. Most existing bias-compensation models express systematic biases as a function of certain deterministic parameters, and least squares adjustment is used for estimating correction parameters. In this paper, the errors-in-variables model is introduced to take random errors in both the observation vector and the design matrix into consideration, based on a weighted total least squares adjustment. Experiments performed with two datasets demonstrate that the proposed method is reliable and the geopositioning accuracy improvement is better compared with a traditional least squares adjustment. Numéro de notice : A2017-197 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12183 En ligne : http://dx.doi.org/10.1111/phor.12183 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84871
in Photogrammetric record > vol 32 n° 157 (March - May 2017) . - pp 48 - 60[article]An approach for estimating time-variable rates from geodetic time series / Olga Didova in Journal of geodesy, vol 90 n° 11 (November 2016)
[article]
Titre : An approach for estimating time-variable rates from geodetic time series Type de document : Article/Communication Auteurs : Olga Didova, Auteur ; Brian Gunter, Auteur ; Riccardo Riva, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 1207 - 1221 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Antarctique
[Termes IGN] calotte glaciaire
[Termes IGN] compensation par moindres carrés
[Termes IGN] données GRACE
[Termes IGN] filtre de Kalman
[Termes IGN] Global Ocean Observing System
[Termes IGN] montée du niveau de la mer
[Termes IGN] niveau moyen des mers
[Termes IGN] optimisation (mathématiques)
[Termes IGN] positionnement par GPS
[Termes IGN] série temporelleRésumé : (Auteur) There has been considerable research in the literature focused on computing and forecasting sea-level changes in terms of constant trends or rates. The Antarctic ice sheet is one of the main contributors to sea-level change with highly uncertain rates of glacial thinning and accumulation. Geodetic observing systems such as the Gravity Recovery and Climate Experiment (GRACE) and the Global Positioning System (GPS) are routinely used to estimate these trends. In an effort to improve the accuracy and reliability of these trends, this study investigates a technique that allows the estimated rates, along with co-estimated seasonal components, to vary in time. For this, state space models are defined and then solved by a Kalman filter (KF). The reliable estimation of noise parameters is one of the main problems encountered when using a KF approach, which is solved by numerically optimizing likelihood. Since the optimization problem is non-convex, it is challenging to find an optimal solution. To address this issue, we limited the parameter search space using classical least-squares adjustment (LSA). In this context, we also tested the usage of inequality constraints by directly verifying whether they are supported by the data. The suggested technique for time-series analysis is expanded to classify and handle time-correlated observational noise within the state space framework. The performance of the method is demonstrated using GRACE and GPS data at the CAS1 station located in East Antarctica and compared to commonly used LSA. The results suggest that the outlined technique allows for more reliable trend estimates, as well as for more physically valuable interpretations, while validating independent observing systems. Numéro de notice : A2016-798 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0918-5 En ligne : http://dx.doi.org/ 10.1007/s00190-016-0918-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82575
in Journal of geodesy > vol 90 n° 11 (November 2016) . - pp 1207 - 1221[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)
[article]
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]Taking 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)PermalinkAutomatic extraction of road networks from GPS traces / Jia Qiu in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 8 (August 2016)PermalinkBenefits of the third frequency signal on cycle slip correction / Xiaohong Zhang in GPS solutions, vol 20 n° 3 (July 2016)PermalinkA correctly weighted least squares adjustment - Part 3 Estimating standard errors in angular observations / Charles D. Ghilani in xyHt, vol 2016 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 correctly weighted least squares adjustment - Part 2 Estimating uncertainties / Charles D. Ghilani in xyHt, vol 2016 n° 2 (February 2016)PermalinkCombination of GNSS and SLR measurements : contribution to the realization of the terrestrial reference frame / Sara Bruni (2016)PermalinkA correctly weighted least squares adjustment - Part 1 Problems from using computed standard deviations / Charles D. Ghilani in xyHt, vol 2016 n° 1 (January 2016)PermalinkEléments de géodésie et de la théorie des moindres carrés / Abdelmajid Ben Hadj Salem (février 2016)PermalinkSurface-based matching of 3D point clouds with variable coordinates in source and target system / Xuming Ge in ISPRS Journal of photogrammetry and remote sensing, vol 111 (January 2016)PermalinkRelative orientation dependent on dual quaternions / Qing H. Sheng in Photogrammetric record, vol 30 n° 151 (September - November 2015)PermalinkTowards a generic method for building-parcel vector data adjustment by least squares / Yann Méneroux in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol II-3 W5 (October 2015)PermalinkOutlier Detection by means of Monte Carlo Estimation including resistant Scale Estimation / Christian Marx in Journal of applied geodesy, vol 9 n° 2 (June 2015)PermalinkGPS satellite surveying / Alfred Leick (2015)PermalinkPermalinkGeneralized integer aperture estimation for partial GNSS ambiguity fixing / Andreas Brack in Journal of geodesy, vol 88 n° 5 (May 2014)PermalinkStepwise decomposition of full-waveform data based on Levenberg Marquardt / Pengcheng Li in Studies in Surveying and Mapping Science, vol 2 (2014)PermalinkBundle adjustment with and without damping / Niclas Börlin in Photogrammetric record, vol 28 n° 144 (December 2013 - February 2014)PermalinkSingular spectrum analysis for modeling seasonal signals from GPS time series / Q. Chen in Journal of geodynamics, vol 72 (December 2013)PermalinkMulti-feature based boresight self-calibration of a terrestrial mobile mapping system / Ting On Chan in ISPRS Journal of photogrammetry and remote sensing, vol 82 (August 2013)Permalink