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Monitoring and prediction of precipitable water vapor using GPS data in Turkey / Kutubuddin Ansari in Journal of applied geodesy, vol 10 n° 4 (December 2016)
[article]
Titre : Monitoring and prediction of precipitable water vapor using GPS data in Turkey Type de document : Article/Communication Auteurs : Kutubuddin Ansari, Auteur ; Omar F. Althuwaynee, Auteur ; Ozsen Corumluoglu, Auteur Année de publication : 2016 Article en page(s) : pp 233 – 245 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse diachronique
[Termes IGN] données météorologiques
[Termes IGN] effet atmosphérique
[Termes IGN] précipitation
[Termes IGN] réfraction atmosphérique
[Termes IGN] réseau géodésique permanent
[Termes IGN] signal GPS
[Termes IGN] température
[Termes IGN] Turquie
[Termes IGN] vapeur d'eauRésumé : (auteur) Although Global Positioning System (GPS) primarily provide accurate estimates of position, velocity and time of the receiver, as the signals pass through the atmoshphere carrying its signatures, thus offers opportunities for atmoshpheric applications. Precipitable water vapor (PWV) is a vital component of the atmosphere and significantly influences atmospheric processes like rainfall and atmospheric temperature. The developing networks of continuously operating GPS can be used to efficiently estimate PWV. The Turkish Permanent GPS Network (TPGN) is employed to monitor PWV information in Turkey. This work primarily aims to derive long-term data of PWV by using atmospheric path delays observed through continuously operating TPGN from November 2014 to October 2015. A least square mathematical approach was then applied to establish the relation of the observed PWV to rainfall and temperature. The modeled PWV was correlated with PWV estimated from GPS data, with an average correlation of 67.10 %–88.60 %. The estimated root mean square error (RMSE) varied from 2.840 to 6.380, with an average of 4.697. Finally, data of TPGN, rainfall, and temperature were obtained for less than 2 months (November 2015 to December 2015) and assessed to validate the mathematical model. This study provides a basis for determining PWV by using rainfall and temperature data. Numéro de notice : A206-973 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2016-0037 En ligne : https://doi.org/10.1515/jag-2016-0037 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83680
in Journal of applied geodesy > vol 10 n° 4 (December 2016) . - pp 233 – 245[article]On 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)
[article]
Titre : On the spectral combination of satellite gravity model, terrestrial and airborne gravity data for local gravimetric geoid computation Type de document : Article/Communication Auteurs : Tao Jian, Auteur ; Yan Ming Wang, Auteur Année de publication : 2016 Article en page(s) : pp 1405 - 1418 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse harmonique
[Termes IGN] bruit blanc
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] erreur
[Termes IGN] géoïde gravimétrique
[Termes IGN] géoïde local
[Termes IGN] Texas (Etats-Unis)
[Termes IGN] varianceRésumé : (Auteur) One of the challenges for geoid determination is the combination of heterogeneous gravity data. Because of the distinctive spectral content of different data sets, spectral combination is a suitable candidate for its solution. The key to have a successful combination is to determine the proper spectral weights, or the error degree variances of each data set. In this paper, the error degree variances of terrestrial and airborne gravity data at low degrees are estimated by the aid of a satellite gravity model using harmonic analysis. For higher degrees, the error covariances are estimated from local gravity data first, and then used to compute the error degree variances. The white and colored noise models are also used to estimate the error degree variances of local gravity data for comparisons. Based on the error degree variances, the spectral weights of satellite gravity models, terrestrial and airborne gravity data are determined and applied for geoid computation in Texas area. The computed gravimetric geoid models are tested against an independent, highly accurate geoid profile of the Geoid Slope Validation Survey 2011 (GSVS11). The geoid computed by combining satellite gravity model GOCO03S and terrestrial (land and DTU13 altimetric) gravity data agrees with GSVS11 to ±1.1 cm in terms of standard deviation along a line of 325 km. After incorporating the airborne gravity data collected at 11 km altitude, the standard deviation is reduced to ±0.8 cm. Numerical tests demonstrate the feasibility of spectral combination in geoid computation and the contribution of airborne gravity in an area of high quality terrestrial gravity data. Using the GSVS11 data and the spectral combination, the degree of correctness of the error spectra and the quality of satellite gravity models can also be revealed. Numéro de notice : A2016-810 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0932-7 En ligne : http://dx.doi.org/10.1007/s00190-016-0932-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82602
in Journal of geodesy > vol 90 n° 12 (December 2016) . - pp 1405 - 1418[article]Optimal placement of a terrestrial laser scanner with an emphasis on reducing occlusions / Morteza Heidari Mozaffar in Photogrammetric record, vol 31 n° 156 (December 2016 - February 2017)
[article]
Titre : Optimal placement of a terrestrial laser scanner with an emphasis on reducing occlusions Type de document : Article/Communication Auteurs : Morteza Heidari Mozaffar, Auteur ; Masood Varshosaz, Auteur Année de publication : 2016 Article en page(s) : pp 374 – 393 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] angle de visée
[Termes IGN] occultation du signal
[Termes IGN] optimisation spatiale
[Termes IGN] point de visibilité
[Termes IGN] semis de points
[Termes IGN] télémétrie laser terrestreRésumé : (auteur) In this paper, a new automated algorithm is proposed that finds the optimum locations of a terrestrial laser scanner (TLS), ensuring completeness of data and minimising the number of scanning locations. The process starts with an initial scan and placing a 3D grid of candidate stations over the entire scan area. A global visibility analysis is then performed to identify the next best view (NBV) location. The TLS is placed on this selected point and a new scan is recorded. Having updated the initial scan with the resulting point cloud, the model is checked for completeness and density. The process is repeated until full coverage of the scan area is achieved by determining the best global arrangement with the minimum number of stations. Experiments show that the algorithm is able to automatically determine the station positions and provide a coverage of 99·5% for simulated data and 91% for real data. Numéro de notice : A2016--002 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12162 Date de publication en ligne : 15/12/2016 En ligne : https://doi.org/10.1111/phor.12162 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83820
in Photogrammetric record > vol 31 n° 156 (December 2016 - February 2017) . - pp 374 – 393[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 106-2016041 RAB Revue Centre de documentation En réserve L003 Disponible 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]Assimilation of SMOS retrievals in the land information system / Clay B. Blankenship in IEEE Transactions on geoscience and remote sensing, vol 54 n° 11 (November 2016)
[article]
Titre : Assimilation of SMOS retrievals in the land information system Type de document : Article/Communication Auteurs : Clay B. Blankenship, Auteur ; Jonathan L. Case, Auteur ; Bradley T. Zavodsky, Auteur ; William L. Crosson, Auteur Année de publication : 2016 Article en page(s) : pp 6320 - 6332 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] carte de la végétation
[Termes IGN] Etats-Unis
[Termes IGN] filtre de Kalman
[Termes IGN] humidité du sol
[Termes IGN] image radar
[Termes IGN] image SMOS
[Termes IGN] modèle numérique de surface
[Termes IGN] radiométrie
[Termes IGN] système d'information foncièreRésumé : (Auteur) The Soil Moisture and Ocean Salinity (SMOS) satellite provides retrievals of soil moisture in roughly the upper 5 cm with a 30-50-km resolution and a mission accuracy requirement of 0.04 cm3/cm-3. These observations can be used to improve land surface model (LSM) soil moisture states through data assimilation (DA). In this paper, SMOS soil moisture retrievals are assimilated into the Noah LSM via an Ensemble Kalman Filter within the National Aeronautics and Space Administration Land Information System. Bias correction is implemented using cumulative distribution function (cdf) matching, with points aggregated by either land cover or soil type to reduce the sampling error in generating the cdfs. An experiment was run for the warm season of 2011 to test SMOS DA and to compare assimilation methods. Verification of soil moisture analyses in the 0-10-cm upper layer and the 0-1-m root zone was conducted using in situ measurements from several observing networks in central and southeastern United States. This experiment showed that SMOS DA significantly increased the anomaly correlation of Noah soil moisture with station measurements from 0.45 to 0.57 in the 0-10-cm layer. Time series at specific stations demonstrates the ability of SMOS DA to increase the dynamic range of soil moisture in a manner consistent with station measurements. Among the bias correction methods, the correction based on soil type performed best at bias reduction but also reduced correlations. The vegetation-based correction did not produce any significant differences compared with using a simple uniform correction curve. Numéro de notice : A2016-913 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2579604 En ligne : http://dx.doi.org/10.1109/TGRS.2016.2579604 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83135
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 11 (November 2016) . - pp 6320 - 6332[article]A global study of NDVI difference among moderate-resolution satellite sensors / Xingwang Fan in ISPRS Journal of photogrammetry and remote sensing, vol 121 (November 2016)PermalinkInterference localization from space: theoretical background / Luca Canzian in Inside GNSS, vol 11 n° 6 (November - December 2016)PermalinkAn advanced GNSS code multipath detection and estimation algorithm / Negin Sokhandan in GPS solutions, vol 20 n° 4 (October 2016)PermalinkLong-term soil moisture dynamics derived from GNSS interferometric reflectometry: a case study for Sutherland, South Africa / Sibylle Vey in GPS solutions, vol 20 n° 4 (October 2016)PermalinkA new ZTD model based on permanent ground-based GNSS-ZTD data / M. Ding in Survey review, vol 48 n° 351 (October 2016)PermalinkOn the significance of periodic signals in noise analysis of GPS station coordinates time series / Janusz Bogusz in GPS solutions, vol 20 n° 4 (October 2016)PermalinkSMAP L-Band microwave radiometer: RFI mitigation prelaunch analysis and first year on-orbit observations / Priscilla N. Mohammed in IEEE Transactions on geoscience and remote sensing, vol 54 n° 10 (October 2016)PermalinkThe influence of elliptical Gaussian laser beam on inversion of terrain information for satellite laser altimeter / Zhou Hui in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 10 (October 2016)PermalinkDynamic occlusion detection and inpainting of in situ captured terrestrial laser scanning point clouds sequence / Chi Chen in ISPRS Journal of photogrammetry and remote sensing, vol 119 (September 2016)PermalinkGNSS interferometric radio occultation / Manuel Martín-Neira in IEEE Transactions on geoscience and remote sensing, vol 54 n° 9 (September 2016)PermalinkNoise removal from hyperspectral image with joint spectral–spatial distributed sparse representation / Jie Li in IEEE Transactions on geoscience and remote sensing, vol 54 n° 9 (September 2016)PermalinkVariance components estimation of residual errors in GPS precise positioning / Darko Anđić in Geodetski vestnik, vol 60 n° 3 (September - November 2016)PermalinkAtmospheric correction in time-series SAR interferometry for land surface deformation mapping : A case study of Taiyuan, China / Wei Tang in Advances in space research, vol 58 n° 3 (August 2016)PermalinkA geometry-free and ionosphere-free multipath mitigation method for BDS three-frequency ambiguity resolution / Dezhong Chen in Journal of geodesy, vol 90 n° 8 (August 2016)PermalinkInterference mitigation in the E5A Galileo band using an open-source simulator / Diego Alonso in Inside GNSS, vol 11 n° 4 (July - August 2016)PermalinkA new computerized ionosphere tomography model using the mapping function and an application to the study of seismic-ionosphere disturbance / Jian Kong in Journal of geodesy, vol 90 n° 8 (August 2016)PermalinkAn adaptive stochastic model for GPS observations and its performance in precise point positioning / J. Z. Zheng in Survey review, vol 48 n° 349 (July 2016)PermalinkA comparative analysis of measurement noise and multipath for four constellations: GPS, BeiDou, GLONASS and Galileo / Changsheng Cai in Survey review, vol 48 n° 349 (July 2016)PermalinkEstimating the intrinsic dimension of hyperspectral images using a noise-whitened eigengap approach / Abderrahim Halimi in IEEE Transactions on geoscience and remote sensing, vol 54 n° 7 (July 2016)PermalinkGNSS multipath detection using three-frequency signal-to-noise measurements / Philip R.R. Strode in GPS solutions, vol 20 n° 3 (July 2016)Permalink