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GRACE-FO precise orbit determination and gravity recovery / Z. Kang in Journal of geodesy, vol 94 n° 9 (September 2020)
[article]
Titre : GRACE-FO precise orbit determination and gravity recovery Type de document : Article/Communication Auteurs : Z. Kang, Auteur ; S. Bettadpur, Auteur ; P. Nagel, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : n° 85 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] bande K
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GRACE
[Termes IGN] double différence
[Termes IGN] interféromètre au laser
[Termes IGN] orbite précise
[Termes IGN] orbitographieRésumé : (auteur) The gravity recovery and climate experiment follow-on (GRACE-FO) satellites, launched in May of 2018, are equipped with geodetic quality GPS receivers for precise orbit determination (POD) and gravity recovery. The primary objective of the GRACE-FO mission is to map the time-variable and mean gravity field of the Earth. To achieve this goal, both GRACE-FO satellites are additionally equipped with a K-band ranging (KBR) system, accelerometers and star trackers. Data processing strategies, data weighting approaches and impacts of observation types and rates are investigated in order to determine the most efficient approach for processing GRACE-FO multi-type data for precise orbit determination and gravity recovery. Two GPS observation types, un-differenced (UD) and double-differenced (DD) observations in general can be used for GPS-based POD and gravity recovery. The GRACE-FO KBR observations are mainly used for gravity recovery, but they can be also used for POD to improve the relative orbit accuracy. The main purpose of this paper is to study the impacts of the DD, UD and KBR observations on GRACE-FO POD and gravity recovery. The precise orbit accuracy is assessed using several tests, which include analysis of orbital fits, satellite laser ranging residuals, KBR range residuals and orbit comparisons. The gravity recovery is validated by comparing different gravity solutions through coefficient-wise comparison, degree difference variances and water height variations over the whole Earth and selected area and river basins. Numéro de notice : A2020-542 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01414-3 Date de publication en ligne : 16/08/2020 En ligne : https://doi.org/10.1007/s00190-020-01414-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95744
in Journal of geodesy > vol 94 n° 9 (September 2020) . - n° 85[article]Homogeneous tree height derivation from tree crown delineation using Seeded Region Growing (SRG) segmentation / Muhamad Farid Ramli in Geo-spatial Information Science, vol 23 n° 3 (September 2020)
[article]
Titre : Homogeneous tree height derivation from tree crown delineation using Seeded Region Growing (SRG) segmentation Type de document : Article/Communication Auteurs : Muhamad Farid Ramli, Auteur ; Khairul Nizam Tahar, Auteur Année de publication : 2020 Article en page(s) : pp 195 - 208 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] Arecaceae
[Termes IGN] croissance des arbres
[Termes IGN] diamètre des arbres
[Termes IGN] hauteur des arbres
[Termes IGN] houppier
[Termes IGN] image captée par drone
[Termes IGN] Malaisie
[Termes IGN] modèle numérique de surface
[Termes IGN] orthoimage
[Termes IGN] pas d'échantillonnage au sol
[Termes IGN] point d'appui
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] QGIS
[Termes IGN] SAGA GIS
[Termes IGN] segmentation en régionsRésumé : (auteur) The demand for tree height derivation is increasing year by year, especially for large plantation and forest area. The conventional method needs a long time to complete tree measurement for large forest area, especially when using a pole, measuring tape, rangefinder, clinometer, and tree climbing. This study aims to evaluate the height of oil palm tree based on crown diameter by using a multi-rotor Unmanned Aerial Vehicle (UAV). Digital Elevation Model (DEM) and orthophoto were generated by using Agisoft software, while oil palm tree crown diameter was delineated by using seed generation with Quantum Geographic Information System (QGIS) and Seeded Region Growing (SRG) segmentation methods in the System for Automated Geoscientific Analysis (SAGA). The study validates the results between the actual tree height and tree height estimated from UAV. The results showed that the orthophoto was successfully generated with a Ground Sampling Distance (GSD) of 2.95 cm and 129 tree crowns were successfully analyzed. The accuracy of the tree height as compared to the actual measurement was 57.7 cm. In conclusion, UAV images are capable of determining the tree height after going through the correct procedure to help foresters in their daily task. Numéro de notice : A2020-562 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10095020.2020.1805366 Date de publication en ligne : 24/08/2020 En ligne : https://doi.org/10.1080/10095020.2020.1805366 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95878
in Geo-spatial Information Science > vol 23 n° 3 (September 2020) . - pp 195 - 208[article]Mapping quality prediction for RTK/PPK-equipped micro-drones operating in complex natural environment / Emmanuel Clédat in ISPRS Journal of photogrammetry and remote sensing, vol 167 (September 2020)
[article]
Titre : Mapping quality prediction for RTK/PPK-equipped micro-drones operating in complex natural environment Type de document : Article/Communication Auteurs : Emmanuel Clédat , Auteur ; Laurent Valentin Jospin, Auteur ; Davide Antonio Cucci, Auteur ; Jan Skaloud, Auteur Année de publication : 2020 Article en page(s) : pp 24 - 38 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] aérotriangulation
[Termes IGN] compensation par faisceaux
[Termes IGN] image captée par drone
[Termes IGN] modèle numérique de terrain
[Termes IGN] plan de vol
[Termes IGN] point d'appui
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] qualité cartographique
[Termes IGN] temps de vol
[Termes IGN] test statistique
[Termes IGN] texture du solRésumé : (auteur) Drone mapping with GNSS-assisted photogrammetry is a highly efficient method for surveying small- or medium-sized areas. However, the mapping quality is not intuitively predictable, particularly in complex environments (with steep and cluttered terrain), in which the quality of the real-time kinematic (RTK) or post-processed kinematic (PPK) positioning varies. We present a method to predict the mapping quality from the information that is available prior to the flight, such as the flight plan, expected flight time, approximate digital terrain model, prevailing surface texture, and embedded sensor characteristics. After detailing the important considerations, we also present the concept of global precision within the context of minimal and efficient ground control point placement in a complex terrain. Finally, we validate the proposed methodology by means of rigorous statistical testing against numerous experiments conducted under different mapping conditions. Numéro de notice : A2020-545 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2020.05.015 Date de publication en ligne : 12/07/2020 En ligne : https://doi.org/10.1016/j.isprsjprs.2020.05.015 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95771
in ISPRS Journal of photogrammetry and remote sensing > vol 167 (September 2020) . - pp 24 - 38[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2020091 RAB Revue Centre de documentation En réserve L003 Disponible 081-2020093 DEP-RECP Revue LASTIG Dépôt en unité Exclu du prêt 081-2020092 DEP-RECF Revue Nancy Dépôt en unité Exclu du prêt An assessment of wide-lane ambiguity resolution methods for multi-frequency multi-GNSS precise point positioning / Viet Duong in Survey review, vol 52 n° 374 (August 2020)
[article]
Titre : An assessment of wide-lane ambiguity resolution methods for multi-frequency multi-GNSS precise point positioning Type de document : Article/Communication Auteurs : Viet Duong, Auteur ; Ken Harima, Auteur ; Suelynn Choy, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 442 - 453 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] combinaison linéaire
[Termes IGN] délai d'obtention de la première position
[Termes IGN] fréquence multiple
[Termes IGN] mesurage de phase
[Termes IGN] mesurage par GNSS
[Termes IGN] phase
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïté
[Termes IGN] station GNSS
[Termes IGN] taux d'échantillonnageRésumé : (auteur) We assess the time-to-first-fix (TTFF) and the ambiguity fixing rate of two PPP wide-lane ambiguity resolution (WL-AR) methods, namely the geometry-based and ionospheric-free (GB-IF) method, and the geometry-free and ionospheric-free (GF-IF) method. First, an optimal GF-IF WL linear combination is selected based on the ratio between the code and carrier phase measurement noise (RT). Then, the relation between ambiguity variance and satellite geometry in the GB-IF WL-AR is investigated. Both simulated and real data from 31 GNSS stations over 37 consecutive days in 2017 were used. Numerical results show that the GF-IF WL-AR method has shorter TTFF and higher ambiguity fixing rate compared to the GB-IF method when RT≤150. However, when RT≥150, the GB-IF method outperforms the GF-IF method. Depending on RT values used, 2–10 min would be required to resolve the WL ambiguities when using GNSS measurements with one second sampling rate. Numéro de notice : A2020-518 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2019.1634339 Date de publication en ligne : 02/07/2019 En ligne : https://doi.org/10.1080/00396265.2019.1634339 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95678
in Survey review > vol 52 n° 374 (August 2020) . - pp 442 - 453[article]GipsyX/RTGx, a new tool set for space geodetic operations and research / Willy I. Bertiger in Advances in space research, vol 66 n° 3 (1 August 2020)
[article]
Titre : GipsyX/RTGx, a new tool set for space geodetic operations and research Type de document : Article/Communication Auteurs : Willy I. Bertiger, Auteur ; Yoaz E. Bar-Sever, Auteur ; A. Dorsey, Auteur ; Bruce J. Haines, Auteur ; N.R. Harvey, Auteur ; Dan Hemberger, Auteur ; Michael B. Heflin, Auteur ; Wenwen Lu, Auteur ; Mark Miller, Auteur ; Angelyn Moore, Auteur ; Dave Murphy, Auteur ; Paul Ries, Auteur ; L.J. Romans, Auteur ; Aurore E. Sibois, Auteur ; Ant Sibthorpe, Auteur ; Bela Szilagyi, Auteur ; Michele Vallisneri, Auteur ; Pascal Willis , Auteur Année de publication : 2020 Projets : 3-projet - voir note / Article en page(s) : pp 469 - 489 Note générale : bibliographie
The research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données DORIS
[Termes IGN] données GNSS
[Termes IGN] données ITGB
[Termes IGN] données TLS (télémétrie)
[Termes IGN] filtre de Kalman
[Termes IGN] horloge atomique
[Termes IGN] horloge du satellite
[Termes IGN] logiciel d'orbitographie
[Termes IGN] positionnement ponctuel précis
[Termes IGN] série temporelle
[Termes IGN] temps réel
[Termes IGN] traitement de données GNSSRésumé : (auteur) GipsyX/RTGx is the Jet Propulsion Laboratory’s (JPL) next generation software package for positioning, navigation, timing, and Earth science using measurements from three geodetic techniques: Global Navigation Satellite Systems (GNSS), Satellite Laser Ranging (SLR), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS); with Very Long Baseline Interferometry (VLBI) under development. The software facilitates combined estimation of geodetic and geophysical parameters using a Kalman filter approach on real or simulated data in both post-processing and in real-time. The estimated parameters include station coordinates and velocities, satellite orbits and clocks, Earth orientation, ionospheric and tropospheric delays. The software is also capable of full realization of a dynamic terrestrial reference through analysis and combination of time series of ground station coordinates.
Applying lessons learned from its predecessors, GIPSY-OASIS and Real Time GIPSY (RTG), GipsyX/RTGx was re-designed from the ground up to offer improved precision, accuracy, usability, and operational flexibility. We present some key aspects of its new architecture, and describe some of its major applications, including Real-time orbit determination and ephemeris predictions in the U.S. Air Force Next Generation GPS Operational Control Segment (OCX), as well as in JPL’s Global Differential GPS (GDGPS) System, supporting User Range Error (URE) of
5 cm RMS; precision post-processing GNSS orbit determination, including JPL’s contributions to the International GNSS Service (IGS) with URE in the 2 cm RMS range; Precise point positioning (PPP) with ambiguity resolution, both statically and kinematically, for geodetic applications with 2 mm horizontal, and 6.5 mm vertical repeatability for static positioning; Operational orbit and clock determination for Low Earth Orbiting (LEO) satellites, such as NASA’s Gravity Recovery and Climate Experiment (GRACE) mission with GRACE relative clock alignment at the 20 ps level; calibration of radio occultation data from LEO satellites for weather forecasting and climate studies; Satellite Laser Ranging (SLR) to GNSS and LEO satellites, DORIS-based and multi-technique orbit determination for LEO; production of terrestrial reference frames and Earth rotation parameters in support of JPL’s contribution to the International Terrestrial Reference Frame (ITRF).Numéro de notice : A2020-575 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Thématique : INFORMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2020.04.015 Date de publication en ligne : 22/04/2020 En ligne : https://doi.org/10.1016/j.asr.2020.04.015 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96369
in Advances in space research > vol 66 n° 3 (1 August 2020) . - pp 469 - 489[article]Performance of BDS triple-frequency positioning based on the modified TCAR method / Yijun Tian in Survey review, vol 52 n° 374 (August 2020)PermalinkAutomated estimation and tools to extract positions, velocities, breaks, and seasonal terms from daily GNSS measurements: illuminating nonlinear Salton Trough deformation / Michael B. Heflin in Earth and space science, vol 7 n° 7 (July 2020)PermalinkBenefits of combining GPS and GLONASS for measuring ocean tide loading displacement / Majid Abbaszadeh in Journal of geodesy, vol 94 n° 7 (July 2020)PermalinkConstrained and network multi-receiver single-epoch RTK positioning / Mieczysław Bakula in Survey review, vol 52 n° 373 (July 2020)PermalinkEffect of spatial correlation on the performances of modernized GPS and Galileo in relative positioning / Noureddine Kheloufi in Geodesy and cartography, vol 46 n° 2 (July 2020)PermalinkEvaluations of the significant wave height products of HY-2B satellite radar altimeters / Yongjun Jia in Marine geodesy, Vol 43 n° 4 (July 2020)PermalinkGPS + Galileo + BeiDou precise point positioning with triple-frequency ambiguity resolution / Pan Li in GPS solutions, Vol 24 n° 3 (July 2020)PermalinkLearning evolving user’s behaviors on location-based social networks / Ruizhi Wu in Geoinformatica, vol 24 n° 3 (July 2020)PermalinkPrecise point positioning with decimetre accuracy using wide-lane ambiguities and triple-frequency GNSS data / Manoj Deo in Journal of applied geodesy, vol 14 n° 3 (July 2020)PermalinkReestimating a minimum acceptable geocoding hit rate for conducting a spatial analysis / Alvaro Briz-Redon in International journal of geographical information science IJGIS, vol 34 n° 7 (July 2020)Permalink