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Improving accuracy of local geoid model using machine learning approaches and residuals of GPS/levelling geoid height / Mosbeh R. Kaloop in Survey review, vol 54 n° 387 (November 2022)
[article]
Titre : Improving accuracy of local geoid model using machine learning approaches and residuals of GPS/levelling geoid height Type de document : Article/Communication Auteurs : Mosbeh R. Kaloop, Auteur ; Samui Pijush, Auteur ; Mostafa Rabah, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 505 - 518 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] apprentissage automatique
[Termes IGN] géoïde gravimétrique
[Termes IGN] géoïde local
[Termes IGN] Koweit
[Termes IGN] MNS SRTM
[Termes IGN] modèle de géopotentiel
[Termes IGN] nivellement avec assistance GPS
[Termes IGN] processus gaussien
[Termes IGN] régression
[Termes IGN] régression multivariée par spline adaptative
[Termes IGN] résiduRésumé : (auteur) This study aims to use GPS/Levelling data and machine learning techniques (MLs) to model a high precision local geoid for Kuwait. To improve the accuracy of a local geoid the global geopotential model and local terrain effect should be incorporated. The geoid model was improved based on the modelling of geoid residuals using three MLs. Minimax Probability Machine Regression (MPMR), Gaussian Process Regression (GPR), and Multivariate Adaptive Regression Splines (MARS) MLs were developed for modelling the calculated geoid residuals. The results show that the accuracy of the three MLs was improved compared to previous studies, and the accuracy of the GPR model was better than the other models. The standard deviations of Kuwait geoid undulation determined by GPS/Levelling, gravimetric, and developed GPR models were 1.377, 1.375, 1.375 m, respectively. Thus, the developed GPR model has successfully predicted an accurate geoid height of Kuwait with maximum variation approaches ±0.02 m. Numéro de notice : A2022-829 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2021.1970918 Date de publication en ligne : 27/08/2021 En ligne : https://doi.org/10.1080/00396265.2021.1970918 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102013
in Survey review > vol 54 n° 387 (November 2022) . - pp 505 - 518[article]Determination of local geometric geoid model for Kuwait / Ahmed Zaki in Journal of applied geodesy, vol 16 n° 4 (October 2022)
[article]
Titre : Determination of local geometric geoid model for Kuwait Type de document : Article/Communication Auteurs : Ahmed Zaki, Auteur ; Yasmeen Elberry, Auteur ; Hamad Al-Ajami, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 393 - 400 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altitude orthométrique
[Termes IGN] conversion altimétrique
[Termes IGN] données GNSS
[Termes IGN] géoïde local
[Termes IGN] Koweit
[Termes IGN] modèle de géopotentiel
[Termes IGN] modèle numérique de surfaceRésumé : (auteur) Determining a precise local geoid is particularly important for converting the Global Navigation Satellite System (GNSS) heights to orthometric heights. The geometric method for computing the geoid has been extensively used for a comparatively small region, which, in some points, interpolates geoid heights based on GNSS-derived heights and levelling heights. Several considerations should be considered when using the geometric method to increase the accuracy of a local geoid. Kuwait is used as a test area in this paper to investigate several features of the geometric method. The achievable precision is one of these aspects, the role of the interpolation method, global geopotential models, and the influence of the topographic effect. The accuracy of the local geoid can be substantially enhanced by integrating a geopotential model with a digital terrain model of the research region. It is possible to get a precision of 2–3 cm. Numéro de notice : A2022-743 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2022-0017 Date de publication en ligne : 23/07/2022 En ligne : https://doi.org/10.1515/jag-2022-0017 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101725
in Journal of applied geodesy > vol 16 n° 4 (October 2022) . - pp 393 - 400[article]Validation and comparison of several global geopotential models with an official quasigeoid solution of Serbia / Marko D. Stanković in Geodetski vestnik, vol 66 n° 3 (September - November 2022)
[article]
Titre : Validation and comparison of several global geopotential models with an official quasigeoid solution of Serbia Type de document : Article/Communication Auteurs : Marko D. Stanković, Auteur ; Oleg Odalovic, Auteur ; Miloš D. Marković, Auteur Année de publication : 2022 Article en page(s) : pp 432 - 448 Note générale : bibliographie Langues : Anglais (eng) Slovène (slv) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] géoïde local
[Termes IGN] modèle de géopotentiel
[Termes IGN] quasi-géoïde
[Termes IGN] réseau de nivellement
[Termes IGN] Serbie
[Termes IGN] surface de référenceRésumé : (auteur) This study aims to analyze the quality of several local reference quasigeoid surfaces obtained from several Global Geopotential Models (GGM) relative to the official quasigeoid solution of Serbia (SQM2011) and GNSS/dh observations for the territory of Serbia. Therefore, validation and comparison of the derived surfaces from the three GGM’s were made based on comparisons of height anomaly derived from GGM’s, SQM2011, and the GNSS/dh observations at the points of the high-precision leveling network. The selected publicly available GGM’s in this study are GOCO05c, SGG- UGM-2, and XGM2019e. Primarily, at 1001 points of the high-precision leveling network, the differences between GGM and GNSS/dh height anomaly were calculated. The final translation parameters were calculated in the iteration procedure, which was then used to calculate the final values of the estimated height anomaly for all GGM’s at 143207 points of the regular grid of spatial resolution 0.5' × 0.5' on the entire territory of Serbia. From the estimated height anomaly, three GGM-derived surfaces were modeled relative to the SQM2011. According to the results of the calculations, SGG-UGM-2 provides the best approximation of the quasi- geoid SQM2011, where the remaining differences have a mean value of 0.01 m, a standard deviation of 0.06 m, and a span of 0.67 m. Numéro de notice : A2022-782 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.15292/geodetski-vestnik.2022.03.432-448 Date de publication en ligne : 20/07/2022 En ligne : https://doi.org/10.15292/geodetski-vestnik.2022.03.432-448 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101865
in Geodetski vestnik > vol 66 n° 3 (September - November 2022) . - pp 432 - 448[article]Réservation
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[article]
Titre : The RTM harmonic correction revisited Type de document : Article/Communication Auteurs : R. Klees, Auteur ; Kurt Seitz, Auteur ; D.C. Slobbe, Auteur Année de publication : 2022 Article en page(s) : n° 39 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse harmonique
[Termes IGN] anomalie de pesanteur
[Termes IGN] Auvergne
[Termes IGN] correction des altitudes
[Termes IGN] géoïde local
[Termes IGN] harmonique sphérique
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] méthode des moindres carrés
[Termes IGN] modèle de géopotentiel local
[Termes IGN] modèle numérique de terrain
[Termes IGN] Norvège
[Termes IGN] quasi-géoïde
[Termes IGN] résiduRésumé : (auteur) In this paper, we derive improved expressions for the harmonic correction to gravity and, for the first time, expressions for the harmonic correction to potential and height anomaly. They need to be applied at stations buried inside the masses to transform internal values into harmonically downward continued values, which are then input to local quasi-geoid modelling using least-squares collocation or least-squares techniques in combination with the remove-compute-restore approach. Harmonic corrections to potential and height anomaly were assumed to be negligible so far resulting in yet unknown quasi-geoid model errors. The improved expressions for the harmonic correction to gravity, and the new expressions for the harmonic correction to potential and height anomaly are used to quantify the approximation errors of the commonly used harmonic correction to gravity and to quantify the magnitude of the harmonic correction to potential and height anomaly. This is done for two test areas with different topographic regimes. One comprises parts of Norway and the North Atlantic where the presence of deep, long, and narrow fjords suggest extreme values for the harmonic correction to potential and height anomaly and corresponding large errors of the commonly used approximation of the harmonic correction to gravity. The other one is located in the Auvergne test area with a moderate topography comprising both flat and hilly areas and therefore may be representative for many areas around the world. For both test areas, two RTM surfaces with different smoothness are computed simulating the use of a medium-resolution and an ultra-high-resolution reference gravity field, respectively. We show that the errors of the commonly used harmonic correction to gravity may be as large as the harmonic correction itself and attain peak values in areas of strong topographic variations of about 100 mGal. Moreover, we show that this correction may introduce long-wavelength biases in the computed quasi-geoid model. Furthermore, we show that the harmonic correction to height anomaly can attain values on the order of a decimetre at some points. Overall, however, the harmonic correction to height anomaly needs to be applied only in areas of strong topographic variations. In flat or hilly areas, it is mostly smaller than one centimetre. Finally, we show that the harmonic corrections increase with increasing smoothness of the RTM surface, which suggests to use a RTM surface with a spatial resolution comparable to the finest scales which can be resolved by the data rather than depending on the resolution of the global geopotential model used to reduce the data. Numéro de notice : A2022-414 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s00190-022-01625-w Date de publication en ligne : 30/05/2022 En ligne : https://doi.org/10.1007/s00190-022-01625-w Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100769
in Journal of geodesy > vol 96 n° 6 (June 2022) . - n° 39[article]Orthometric, normal and geoid heights in the context of the Brazilian altimetric network / Danilos Fernandes de Medeiros in Boletim de Ciências Geodésicas, vol 28 n° 1 ([01/03/2022])
[article]
Titre : Orthometric, normal and geoid heights in the context of the Brazilian altimetric network Type de document : Article/Communication Auteurs : Danilos Fernandes de Medeiros, Auteur ; Giuliano Sant’Anna Marotta, Auteur ; Carlos Alberto Moreno Chaves, Auteur ; George Sand Leão Araújo de França, Auteur Année de publication : 2022 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altitude normale
[Termes IGN] altitude orthométrique
[Termes IGN] Brésil
[Termes IGN] géoïde local
[Termes IGN] incertitude des données
[Termes IGN] réseau altimétrique nationalRésumé : (auteur) The extensive use of GNSS positioning, combined with the importance of precise geoid heights for transformation between geodetic and orthometric heights, brings up the discussion of the influence of data uncertainties and the use of variable density values on these estimates. In this sense, we analyze the influence of the topographic masses density distribution and the data uncertainty on the computation of orthometric and geoid heights in stations of the High Precision Altimetric Network of Brazil, considering the Helmert and Mader methods. For this, we use 569 stations whose values of geodetic and normal heights, gravity, and geopotential numbers are known. The results indicate that orthometric heights are more sensitive to density values and to greater heights than to the Helmert and Mader methods applied. Also, we verify that the normal and orthometric heights present significant differences for the analyzed stations, considering the high correlation between the heights, which provide small values of uncertainty. However, our analyses show that the use of the Mader method, along with variable density values, provides either more rigorous or more reliable results. Numéro de notice : A2022-682 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : sans En ligne : https://revistas.ufpr.br/bcg/article/view/86198/46466 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101542
in Boletim de Ciências Geodésicas > vol 28 n° 1 [01/03/2022][article]Empirical comparison between stochastic and deterministic modifiers over the French Auvergne geoid computation test-bed / Ropesh Goyal in Survey review, vol 54 n° 382 (January 2022)PermalinkGeoid determination through the combined least-squares adjustment of GNSS/levelling/gravity networks – a case study in Linyi, China / Dongmei Guo in Survey review, Vol 53 n° 381 (November 2021)PermalinkHigh-resolution geoid modeling using least squares modification of Stokes and Hotine formulas in Colorado / Mustafa Serkan Işık in Journal of geodesy, vol 95 n° 5 (May 2021)PermalinkHeight system unification and estimation of the lithospheric structure beneath Vietnam through high-resolution gravity field and quasigeoid modeling / Dinh Toan Vu (2021)PermalinkError propagation in regional geoid computation using spherical splines, least-squares collocation, and Stokes’s formula / Vegard Ophaug in Journal of geodesy, vol 94 n° 12 (December 2020)PermalinkPossibility to determine highly precise geoid for Egypt territory / Moamen Awad Habib Gad in Geodetski vestnik, vol 64 n° 4 (December 2020 - February 2021)PermalinkOptimizing local geoid undulation model using GPS/levelling measurements and heuristic regression approaches / Mosbeh R. Kaloop in Survey review, vol 52 n° 375 (November 2020)PermalinkIntegration of airborne gravimetry data filtering into residual least-squares collocation: example from the 1 cm geoid experiment / Martin Willberg in Journal of geodesy, vol 94 n° 8 (August 2020)PermalinkError propagation for the Molodensky G1 term / Jack C. McCubbine in Journal of geodesy, vol 93 n°6 (June 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)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)PermalinkUsing radial basis functions in airborne gravimetry for local geoid improvement / Xiaopeng Li in Journal of geodesy, vol 92 n° 5 (May 2018)PermalinkKriging and moving window kriging on a sphere in geometric (GNSS/levelling) geoid modelling / M. Ligas in Survey review, vol 50 n° 359 (March 2018)PermalinkRegional geoid computation by least squares modified Hotine’s formula with additive corrections / Silja Märdla in Journal of geodesy, vol 92 n° 3 (March 2018)PermalinkThe first Australian gravimetric quasigeoid model with location-specific uncertainty estimates / Will E. Featherstone in Journal of geodesy, vol 92 n° 2 (February 2018)PermalinkApplying the GOCE-based GGMs for the quasi-geoid modelling of Finland / Timo Saari in Journal of applied geodesy, vol 12 n° 1 (January 2018)PermalinkAssessing the quality of GEOID12B model through field surveys / Ahmed F. Elaksher in Journal of applied geodesy, vol 12 n° 1 (January 2018)PermalinkContribution actuelle de la calotte Antarctique à la variation du niveau marin / Clémence Chupin (2018)PermalinkHeight biases of SRTM DEM related to EGM96: from a global perspective to regional practice / A. Üstün in Survey review, vol 50 n° 358 (January 2018)PermalinkOn the equivalence of spherical splines with least-squares collocation and Stokes’s formula for regional geoid computation / Vegard Ophaug in Journal of geodesy, vol 91 n° 11 (November 2017)PermalinkOn the spectral combination of satellite gravity model, terrestrial and airborne gravity data for local gravimetric geoid computation / Tao Jian in Journal of geodesy, vol 90 n° 12 (December 2016)PermalinkA spatial analysis of GEOID03 and GEOID09 in Connecticut / Kazi Arifuzzaman in Journal of applied geodesy, vol 10 n° 2 (June 2016)PermalinkThe Canadian Geodetic Vertical Datum of 2013 (CGVD2013) / Marc Véronneau in Geomatica, vol 70 n° 1 (March 2016)PermalinkGravity field modelling and gravimetry / Jan Krynski in Geodesy and cartography, vol 64 n° 2 (December 2015)PermalinkThe status of measurement of the Mediterranean mean dynamic topography by geodetic techniques / Philip L. Woodworth in Journal of geodesy, vol 89 n° 8 (August 2015)PermalinkHow good is AUSGeoid09 in the Blue Mountains ? / Joseph Allerton in Position, n° 77 (June - July 2015)PermalinkDevelopment of new hybrid geoid model for Japan, "GSIGEO2011" / Basara Miyahara in Bulletin of the GeoSpatial Information authority of Japan, vol 62 (December 2014)PermalinkLowest astronomical tide in the North Sea derived from a vertically referenced shallow water model, and an assessment of its suggested sense of safety / D. Slobbe in Marine geodesy, vol 36 n° 1 (January - March 2013)PermalinkNew constraints on the origin of the Hawaiian swell from wavelet analysis of the geoid-to-topography ratio / Cécilia Cadio in Earth and planetary science letters, vol 359–360 (15 December 2012)PermalinkAssessment of the GOCE-based global gravity models in Canada / Elmas Sinem Ince in Geomatica, vol 66 n° 2 (June 2012)PermalinkChoix d'un modèle géopotentiel global pour la détermination du géoïde en Algérie / N. Rabehi in Bulletin des sciences géographiques, n° 27 (juin 2012)PermalinkPermalinkEstimating geoid height change in North America: past, present and future / T. Jacob in Journal of geodesy, vol 86 n° 5 (May 2012)PermalinkThe US Gravimetric Geoid of 2009 (USGG2009): model development and evaluation / Y. Wang in Journal of geodesy, vol 86 n° 3 (March 2012)PermalinkPacific geoid anomalies revisited in light of thermochemical oscillating domes in the lower mantle / Cécilia Cadio in Earth and planetary science letters, vol 306 n° 1-2 (June 2011)PermalinkThe AUSGeoid09 model of the Australian Height Datum / Will E. Featherstone in Journal of geodesy, vol 85 n° 3 (March 2011)PermalinkDéveloppement d’un système léger de gravimétrie mobile : LiMoG / José Cali in Revue des Systèmes (RS) - Instrumentation - Mesure - Métrologie (Série I2M), vol 10 n° 3-4 (Juillet - Décembre 2010)PermalinkTuning a gravimetric quasigeoid to GPS-levelling by non-stationary least-squares collocation / N. Darbehesti in Journal of geodesy, vol 84 n° 7 (July 2010)PermalinkAssessing the accuracy of GEOID03 and GEOID09 in Connecticut / Thomas H. Meyer in SaLIS Surveying and land information science, vol 70 n° 2 (Summer 2010)PermalinkEstablishment of an empirical Geoid Model for a small geographic area: a case study of Port Harcourt, Nigeria / J. Olaleye in SaLIS Surveying and land information science, vol 70 n° 1 (Spring 2010)PermalinkA bias-free geodetic boundary value problem approach to height datum unification / Alireza A. Ardalan in Journal of geodesy, vol 84 n° 2 (February 2010)PermalinkFundamental gravity network of the Republic Croatia in the function of control and improving of national and European geoid model / I. Grgic (01/01/2010)PermalinkPreliminary works on creation of the new geoid model HRG2009 / I. Grgic (01/01/2010)PermalinkPermalinkSea surface topography and marine geoid by airborne laser altimetry and shipborne ultrasound altimetry / Philippe Limpach (2010)Permalink