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Real-time sea-level monitoring using Kalman filtering of GNSS-R data / Joakim Strandberg in GPS solutions, vol 23 n° 3 (July 2019)
[article]
Titre : Real-time sea-level monitoring using Kalman filtering of GNSS-R data Type de document : Article/Communication Auteurs : Joakim Strandberg, Auteur ; Thomas Hobiger, Auteur ; Rüdiger Haas, Auteur Année de publication : 2019 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] B-Spline
[Termes IGN] déformation de la croute terrestre
[Termes IGN] filtre de Kalman
[Termes IGN] glace de mer
[Termes IGN] marée terrestre
[Termes IGN] niveau de la mer
[Termes IGN] rapport signal sur bruit
[Termes IGN] réflectométrie par GNSS
[Termes IGN] surface de la mer
[Termes IGN] temps réel
[Vedettes matières IGN] AltimétrieRésumé : (auteur) Current GNSS-R (GNSS reflectometry) techniques for sea surface measurements require data collection over longer periods, limiting their usability for real-time applications. In this work, we present a new, alternative GNSS-R approach based on the unscented Kalman filter and the so-called inverse modeling approach. The new method makes use of a mathematical description that relates SNR (signal-to-noise ratio) variations to multipath effects and uses a B-spline formalism to obtain time series of reflector height. The presented algorithm can provide results in real time with a precision that is significantly better than spectral inversion methods and almost comparable to results from inverse modeling in post-processing mode. To verify the performance, the method has been tested at station GTGU at the Onsala Space Observatory, Sweden, and at the station SPBY in Spring Bay, Australia. The RMS (root mean square) error with respect to nearby tide gauge data was found to be 2.0 cm at GTGU and 4.8 cm at SPBY when evaluating the output corresponding to real-time analysis. The method can also be applied in post-processing, resulting in RMS errors of 1.5 cm and 3.3 cm for GTGU and SPBY, respectively. Finally, based on SNR data from GTGU, it is also shown that the Kalman filter approach is able to detect the presence of sea ice with a higher temporal resolution than the previous methods and traditional remote sensing techniques which monitor ice in coastal regions. Numéro de notice : A2019-198 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-019-0851-1 En ligne : https://doi.org/10.1007/s10291-019-0851-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92653
in GPS solutions > vol 23 n° 3 (July 2019)[article]Error propagation for the Molodensky G1 term / Jack C. McCubbine in Journal of geodesy, vol 93 n°6 (June 2019)
[article]
Titre : Error propagation for the Molodensky G1 term Type de document : Article/Communication Auteurs : Jack C. McCubbine, Auteur ; Will E. Featherstone, Auteur ; Nicholas J. Brown, Auteur Année de publication : 2019 Article en page(s) : pp 889 - 898 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] anomalie de pesanteur
[Termes IGN] Australie
[Termes IGN] géoïde gravimétrique
[Termes IGN] géoïde local
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] incertitude de position
[Termes IGN] intégrale de Stokes
[Termes IGN] modèle numérique de surface
[Termes IGN] problème des valeurs limites
[Termes IGN] propagation d'erreur
[Termes IGN] quasi-géoïde
[Termes IGN] transformation de coordonnéesRésumé : (auteur) Molodensky G terms are used in the computation of the quasigeoid. We derive error propagation formulas that take into account uncertainties in both the free air gravity anomaly and a digital elevation model. These are applied to generate G1 terms and their errors on a 1″ × 1″ grid over Australia. We use these to produce Molodensky gravity anomaly and accompanying uncertainty grids. These uncertainties have average value of 2 mGal with maximum of 54 mGal. We further calculate a gravimetric quasigeoid model by the remove–compute–restore technique. These Molodensky gravity anomaly uncertainties lead to quasigeoid uncertainties with a mean of 4 mm and maximum of 80 mm when propagated through a deterministically modified Stokes’s integral over an integration cap radius of 0.5°. Numéro de notice : A2019-351 Affiliation des auteurs : non IGN Thématique : MATHEMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-018-1211-6 Date de publication en ligne : 09/11/2018 En ligne : https://doi.org/10.1007/s00190-018-1211-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93395
in Journal of geodesy > vol 93 n°6 (June 2019) . - pp 889 - 898[article]Analysis of ocean tide loading displacements by GPS kinematic precise point positioning: a case study at the China coastal site SHAO / H. Zhao in Survey review, vol 51 n° 365 (March 2019)
[article]
Titre : Analysis of ocean tide loading displacements by GPS kinematic precise point positioning: a case study at the China coastal site SHAO Type de document : Article/Communication Auteurs : H. Zhao, Auteur ; Q. Zhang, Auteur ; R. Tu, Auteur ; Z. Liu, Auteur Année de publication : 2019 Article en page(s) : pp 172 - 182 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse spectrale
[Termes IGN] Chine
[Termes IGN] données GPS
[Termes IGN] données marégraphiques
[Termes IGN] GPS en mode cinématique
[Termes IGN] littoral
[Termes IGN] marée océanique
[Termes IGN] positionnement ponctuel précis
[Termes IGN] série temporelle
[Termes IGN] surcharge océaniqueRésumé : (Auteur) Ocean tide loading (OTL) displacement amplitudes and phase lags of SHAO site are estimated by global positioning system (GPS), kinematic precise point positioning (PPP) and spectral analysis using 19 years of continuous GPS observations. In kinematic PPP, the 66 additional harmonic displacement parameters are replaced by the three time-varying displacement parameters without a priori modelled OTL displacements. By comparing the results with predictions from hybrid regional/global models, we are able to demonstrate that GPS/model agreements are at the level of 0.2 mm (horizontal) and 0.6 mm (vertical) for the four lunar constituents, 0.4 mm (horizontal) and 1.35 mm (vertical) for the four solar/sidereal constituents, and 0.2 mm (horizontal) and 0.3 mm (vertical) for the three long-period constituents. Finally, we conclude that GPS-derived lunar constituents can substitute for the model corrections in GPS data processing and the accuracy of GPS-derived solar/sidereal constituents needs to be improved by further studies. Numéro de notice : A2019-190 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2017.1407392 Date de publication en ligne : 30/11/2017 En ligne : https://doi.org/10.1080/00396265.2017.1407392 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92634
in Survey review > vol 51 n° 365 (March 2019) . - pp 172 - 182[article]Deflections of the vertical from full-tensor and single-instrument gravity gradiometry / Christopher Jekeli in Journal of geodesy, vol 93 n° 3 (March 2019)
[article]
Titre : Deflections of the vertical from full-tensor and single-instrument gravity gradiometry Type de document : Article/Communication Auteurs : Christopher Jekeli, Auteur Année de publication : 2019 Article en page(s) : pp 369 - 382 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] déviation de la verticale
[Termes IGN] faille géologique
[Termes IGN] gradient de gravitation
[Termes IGN] intégration de données
[Termes IGN] levé gravimétriqueRésumé : (Auteur) Gravity gradiometry on a moving platform, whether ground or airborne, has the potential to offer an efficient and accurate determination of the deflection of the vertical by simple line integration. A significant error in this process is a trend error that results from the integration of systematic gradient errors. Using an airborne full-tensor gradiometry data set of regularly spaced and intersecting tracks over a 10 km square region and the USDOV2012 vertical deflection model to calibrate these long wavelength errors, it is shown that the gradient-derived deflections agree with the USDOV2012 model at the level of 0.6–0.9 arcsec. Moreover, it is shown by graphical inspection that these differences represent high-frequency signal rather than error. Another data processing technique is examined using only (simulated) single-gradiometer instrument data, i.e., the local differential curvature components, (Γyy−Γxx)/2 and Γxy, of the gravity field. While in theory these data can yield deflection components using two parallel data tracks, the results in the tested case are unsatisfactory due to implicit additional cross-track integration errors that accumulate systematically. The analysis thus demonstrates the importance of using the individual horizontal gradient components, Γxx, Γyy, to derive the deflection of the vertical. Numéro de notice : A2019-152 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-018-1162-y Date de publication en ligne : 11/07/2018 En ligne : https://doi.org/10.1007/s00190-018-1162-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92491
in Journal of geodesy > vol 93 n° 3 (March 2019) . - pp 369 - 382[article]A generalized theory of the figure of the Earth : formulae / Chengli Huang in Journal of geodesy, vol 93 n° 3 (March 2019)
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Titre : A generalized theory of the figure of the Earth : formulae Type de document : Article/Communication Auteurs : Chengli Huang, Auteur ; Yu Liu, Auteur ; Chenjun Liu, Auteur ; Mian Zhang, Auteur Année de publication : 2019 Article en page(s) : pp 297 - 317 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie
[Termes IGN] croute terrestre
[Termes IGN] ellipticité (géométrie)
[Termes IGN] équation de Clairaut
[Termes IGN] figure de la Terre
[Termes IGN] surface de référenceRésumé : (Auteur) Traditionally a laterally homogeneous and spherical base Earth model (e.g., the PREM model) is considered as input when computing the Earth’s equipotential surfaces, which are then resulted to be in symmetric shape. However, the Earth, known with a complex distribution of interior material and density, especially in the upper mantle and the crust, cannot be treated as a symmetric sphere. Recently, a CRUST1.0 model of crust layer is published and well accepted. But the effect caused by the asymmetric crust (and mantle) on equilibrium figures of the Earth cannot be analyzed by the traditional theories. A generalized theory of the figure of the Earth to third-order precision is firstly proposed in this paper, as well as the iterative calculation strategy to solve the complex equation system. In order to validate this generalized theory, the degeneration of this generalized theory with the PREM model is made and is compared with traditional theories, and it is shown that the result of this generalized theory, after degeneration, is consistent very well with traditional theory. Meanwhile, the effect (including both the direct and indirect effects) of the crust layer, from the CRUST1.0 model, on the figures of equipotential surfaces of the Earth’s interior, as well as their effects on the global dynamics flattening, will be presented as an application of this theory in accompanying paper. Numéro de notice : A2019-150 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-018-1159-6 Date de publication en ligne : 15/06/2018 En ligne : https://doi.org/10.1007/s00190-018-1159-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92488
in Journal of geodesy > vol 93 n° 3 (March 2019) . - pp 297 - 317[article]A generalized theory of the figure of the Earth : on the global dynamical flattening / Chenjun Liu in Journal of geodesy, vol 93 n° 3 (March 2019)PermalinkFFT swept filtering: a bias-free method for processing fringe signals in absolute gravimeters / Petr Křen in Journal of geodesy, vol 93 n° 2 (February 2019)PermalinkInfluence of subdaily model for polar motion on the estimated GPS satellite orbits / Natalia Panafidina in Journal of geodesy, vol 93 n° 2 (February 2019)PermalinkA new global grid model for the determination of atmospheric weighted mean temperature in GPS precipitable water vapor / Liangke Huang in Journal of geodesy, vol 93 n° 2 (February 2019)PermalinkOn the assimilation of absolute geodetic dynamic topography in a global ocean model: impact on the deep ocean state / Alexey Androsov in Journal of geodesy, vol 93 n° 2 (February 2019)PermalinkPermalinkAtmospheric angular momentum related to Earth rotation studies: history and modern developments / David A. Salstein (2019)PermalinkCorrelated atom accelerometers for mapping the Earth gravity field from space / Thomas Lévèque (2019)PermalinkDPOD2014 : A new DORIS extension of ITRF2014 for precise orbit determination / Guilhem Moreaux in Advances in space research, vol 63 n° 1 (1 January 2019)PermalinkEnhancing the predictability of least-squares collocation through the integration with least-squares-support vector machine / Hossam Talaat Elshambaky in Journal of applied geodesy, vol 13 n° 1 (January 2019)PermalinkEvaluation of terrestrial and airborne gravity data over Antarctica : a generic approach / Philipp Zingerle in Journal of geodetic science, vol 9 n° 1 (January 2019)PermalinkHow IGN (France) computed the so-called "centre of gravity" of physical Europe in 1989 and 2004 / Jean-François Hangouët (2019)PermalinkMass variation observing system by high low inter-satellite links (MOBILE) : a new concept for sustained observation of mass transport from space / Roland Pail in Journal of geodetic science, vol 9 n° 1 (January 2019)PermalinkOptimization of optical clock network for the geopotential determination / Guillaume Lion (2019)PermalinkReconciling upper mantle seismic velocity and density structure below ocean basins / Isabelle Panet (2019)PermalinkPermalinkAn analysis of gravitational gradients in rotated frames and their relation to oriented mass sources / Isabelle Panet in Journal of geophysical research : Solid Earth, vol 123 n° 12 (December 2018)PermalinkAUSGeoid2020 combined gravimetric–geometric model : location-specific uncertainties and baseline-length-dependent error decorrelation / Nicholas J. Brown in Journal of geodesy, vol 92 n° 12 (December 2018)PermalinkLa forme de la terre dans l'histoire occidentale / Xavier Della Chiesa in XYZ, n° 157 (décembre 2018 - février 2019)PermalinkIdentification and extraction of seasonal geodetic signals due to surface load variations / Stacy Larochelle in Journal of geophysical research : Solid Earth, vol 123 n° 12 (December 2018)Permalink