Détail de l'auteur
Auteur Marek Ziebart |
Documents disponibles écrits par cet auteur (7)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Effectiveness of observation-domain sidereal filtering for GPS precise point positioning / Christopher Atkins in GPS solutions, vol 20 n° 1 (January 2016)
[article]
Titre : Effectiveness of observation-domain sidereal filtering for GPS precise point positioning Type de document : Article/Communication Auteurs : Christopher Atkins, Auteur ; Marek Ziebart, Auteur Année de publication : 2016 Article en page(s) : pp 111 - 122 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] correction du trajet multiple
[Termes IGN] phase
[Termes IGN] positionnement ponctuel précis
[Termes IGN] propagation ionosphérique
[Termes IGN] séisme
[Termes IGN] variance d'Allan
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) Sidereal filtering is a technique used to reduce errors caused by multipath in the positioning of static receivers via the Global Positioning System (GPS). It relies upon the receiver and its surrounding environment remaining static from one day to the next and takes advantage of the approximately sidereal repeat time of the GPS constellation geometry. The repeating multipath error can thus be identified, usually in the position domain, and largely removed from the following day. We describe an observation-domain sidereal filter algorithm that operates on undifferenced ionospheric-free GPS carrier phase measurements to reduce errors caused by multipath. It is applied in the context of high-rate (1 Hz) precise point positioning of a static receiver. An observation-domain sidereal filter (ODSF) is able to account for the slightly different repeat times of each GPS satellite, unlike a position-domain sidereal filter (PDSF), and can hence be more effective at reducing high-frequency multipath error. Using 8-h long datasets of GPS measurements from two different receivers with different antenna types and contrasting environments, the ODSF algorithm is shown overall to yield a position time series 5–10 % more stable, in terms of Allan deviation, than a PDSF over nearly all time intervals below about 200 s in length. This may be particularly useful for earthquake and tsunami early warning systems where the accurate measurement of small displacements of the ground over the period of just a few minutes is crucial. However, the sidereal filters are also applied to a third dataset during which two short episodes of particularly high-frequency multipath error were identified. These two periods are analyzed in detail and illustrate the limitations of using sidereal filters with important implications for other methods of correcting for multipath at the observation level. Numéro de notice : A2016-605 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0473-1 En ligne : http://dx.doi.org/10.1007/s10291-015-0473-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81806
in GPS solutions > vol 20 n° 1 (January 2016) . - pp 111 - 122[article]Urban positioning on a smartphone: real-time shadow matching using GNSS and 3D city models / Lei Wang in Inside GNSS, vol 8 n° 6 (November - December 2013)
[article]
Titre : Urban positioning on a smartphone: real-time shadow matching using GNSS and 3D city models Type de document : Article/Communication Auteurs : Lei Wang, Auteur ; Paul D. Groves, Auteur ; Marek Ziebart, Auteur Année de publication : 2013 Article en page(s) : 13 p. ; pp 44 - 56 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] canyon urbain
[Termes IGN] correction du trajet multiple
[Termes IGN] milieu urbain
[Termes IGN] signal GNSS
[Termes IGN] téléphone intelligent
[Termes IGN] trajet multipleRésumé : (Editeur) This article presents a smartphone-based system that uses the GNSS signal 'shadows' cast by buildings - usually the satellite-signal blocking bane of navigating in narrow urban canyons - to improve the accuracy of street-level positioning. The authors present the results of field tests that reveal dramatic reduction of positioning errors and improved availability. Numéro de notice : A2013-728 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75694
in Inside GNSS > vol 8 n° 6 (November - December 2013) . - 13 p. ; pp 44 - 56[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 159-2013061 SL Revue Centre de documentation Revues en salle Disponible Documents numériques
en open access
a2013-728_urban_positioning_wang.pdfAdobe Acrobat PDF Doppler-aided positioning: Improving single-frequency in the urban environment / M. Bahrami in GPS world, vol 22 n° 5 (May 2011)
[article]
Titre : Doppler-aided positioning: Improving single-frequency in the urban environment Type de document : Article/Communication Auteurs : M. Bahrami, Auteur ; Marek Ziebart, Auteur Année de publication : 2011 Article en page(s) : pp 47 - 56 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] données Doppler
[Termes IGN] effet Doppler
[Termes IGN] géonavigateur
[Termes IGN] lissage de données
[Termes IGN] mesurage de pseudo-distance
[Termes IGN] milieu urbain
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] récepteur monofréquenceRésumé : (Editeur) What do a GPS receiver, a policeman’s speed gun, a weather radar, and some medical diagnostic equipment have in common? Give up? They all make use of the Doppler effect. First proposed in 1842 by the Austrian mathematician and physicist, Christian Doppler, it is the change in the perceived frequency of a wave when the transmitter and the receiver are in relative motion. Doppler introduced the concept in an attempt to explain the shift in the color of light from certain binary stars. Three years later, the effect was tested for sound waves by the Dutch scientist Christophorus Buys Ballot. [...] The beginning of the space age heralded a new application of the Doppler effect. By measuring the shift in the received frequency of the radio beacon signals transmitted by Sputnik 1 from a known location, scientists were able to determine the orbit of the satellite. And shortly thereafter, they determined that if the orbit of a satellite was known, then the position of a receiver could be determined from the shift. That realization led to the development of the United States Navy Navigation Satellite System, commonly known as Transit, with the first satellite being launched in 1961. Initially classified, the system was made available to civilians in 1967 and was widely used for navigation and precise positioning until it was shut down in 1996. The Soviet Union developed a similar system called Tsikada and a special military version called Parus. These systems are also assumed to be no longer in use — at least for navigation. GPS and other global navigation satellite systems use the Doppler shift of the received carrier frequencies to determine the velocity of a moving receiver. Doppler-derived velocity is far more accurate than that obtained by simply differencing two position estimates. But GPS Doppler measurements can be used in other ways, too. In this month’s column, we look at how Doppler measurements can be used to smooth noisy code-based pseudoranges to improve the precision of autonomous positioning as well as to improve the availability of single-frequency real-time kinematic positioning, especially in urban environments. Numéro de notice : A2011-180 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30958
in GPS world > vol 22 n° 5 (May 2011) . - pp 47 - 56[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 067-2011051 RAB Revue Centre de documentation En réserve L003 Disponible DORIS/SLR POD modeling improvements for Jason-1 and Jason-2 / Nikita P. Zelensky in Advances in space research, vol 46 n° 12 (15/12/2010)
[article]
Titre : DORIS/SLR POD modeling improvements for Jason-1 and Jason-2 Type de document : Article/Communication Auteurs : Nikita P. Zelensky, Auteur ; Franck G. Lemoine, Auteur ; Marek Ziebart, Auteur ; Ant Sibthorpe, Auteur ; Pascal Willis , Auteur ; Brian D. Beckley, Auteur ; Steven M. Klosko, Auteur ; Douglas S. Chinn, Auteur ; David D. Rowlands, Auteur ; Scott B. Luthcke, Auteur ; Despina E. Pavlis, Auteur ; Vincenza Luceri, Auteur Année de publication : 2010 Article en page(s) : pp 1541 - 1558 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse de sensibilité
[Termes IGN] données TLS (télémétrie)
[Termes IGN] Jason
[Termes IGN] orbitographie
[Termes IGN] positionnement par DORIS
[Termes IGN] résidu
[Termes IGN] retard troposphérique
[Termes IGN] télémétrie laser sur satelliteRésumé : (auteur) The long-term stability and the precision of the satellite orbit is a critical component of the Jason-1 and Jason-2 (OSTM) Missions, providing the reference frame for ocean mapping using altimeter data. DORIS tracking in combination with SLR has provided orbits, which are both highly accurate and consistent across missions using the latest and most accurate POD models. These models include GRACE-derived static and time varying gravity fields and a refined Terrestrial Reference Frame based on SLR and DORIS data yielding a uniform station complement. Additional improvements have been achieved based on advances in modeling the satellite surface forces and the tropospheric path delay for DORIS measurements. This paper presents these model improvements for Jason-1 and Jason-2, including a description of DORIS sensitivity to error in tropospheric path delay. We show that the detailed University College London (UCL) radiation pressure model for Jason-1, which includes self-shadowing and thermal re-radiation, is superior to the use of a macromodel for radiation pressure surface force modeling. Improvements in SLR residuals are seen over all Beta-prime angles for both Jason-1 and Jason-2 using the UCL model, with the greatest improvement found over regimes of low Beta-prime where orbit Earth shadowing is maximum. The overall radial orbit improvement for Jason-1 using the UCL model is 3 mm RMS, as corroborated by the improvement in the independent altimeter crossover data. Special attention is paid to Jason-2 POD to assess improvements gained with the latest advances in DORIS receiver technology. Tests using SLR and altimeter crossover residuals suggest the Jason-2 reduced-dynamic DORIS-only, SLR/DORIS, and GPS orbits have all achieved 1-cm radial accuracy. Tests using independent SLR data acquired at high elevation show an average fit value of 1.02 cm for the DORIS-only and 0.94 cm for the GPS reduced-dynamic orbits. Orbit differences suggest that the largest remaining errors in the Jason-2 dynamic orbit solutions are due to radiation pressure mis-modeling and variations in the geopotential not captured in the GRACE-derived annual terms. Numéro de notice : A2010-652 Affiliation des auteurs : IGN+Ext (1940-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2010.05.008 Date de publication en ligne : 13/05/2010 En ligne : https://doi.org/10.1016/j.asr.2010.05.008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91722
in Advances in space research > vol 46 n° 12 (15/12/2010) . - pp 1541 - 1558[article]Towards development of a consistent orbit series for TOPEX, Jason-1, and Jason-2 / Franck G. Lemoine in Advances in space research, vol 46 n° 12 (15/12/2010)
[article]
Titre : Towards development of a consistent orbit series for TOPEX, Jason-1, and Jason-2 Type de document : Article/Communication Auteurs : Franck G. Lemoine, Auteur ; Nikita P. Zelensky, Auteur ; Douglas S. Chinn, Auteur ; Marek Ziebart, Auteur ; Despina E. Pavlis, Auteur ; David D. Rowlands, Auteur ; Brian D. Beckley, Auteur ; Scott B. Luthcke, Auteur ; Pascal Willis , Auteur ; et al., Auteur Année de publication : 2010 Article en page(s) : pp 1513 - 1540 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] cohérence des données
[Termes IGN] données altimétriques
[Termes IGN] données DORIS
[Termes IGN] force de gravitation
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] Jason
[Termes IGN] niveau moyen des mers
[Termes IGN] orbitographie
[Termes IGN] série temporelle
[Termes IGN] surcharge océanique
[Termes IGN] télémétrie laser sur satellite
[Termes IGN] TOPEX-PoseidonRésumé : (Auteur) The TOPEX/Poseidon, Jason-1 and Jason-2 set of altimeter data now provide a time series of synoptic observations of the ocean that span nearly 17 years from the launch of TOPEX in 1992. The analysis of the altimeter data including the use of altimetry to monitor the global change in mean sea level requires a stable, accurate, and consistent orbit reference over the entire time span. In this paper, we describe the recomputation of a time series of orbits that rely on a consistent set of reference frames and geophysical models. The recomputed orbits adhere to the IERS 2003 standards for ocean and earth tides, use updates to the ITRF2005 reference frame for both the SLR and DORIS stations, apply GRACE-derived models for modeling of the static and time-variable gravity, implement the University College London (UCL) radiation pressure model for Jason-1, use improved troposphere modeling for the DORIS data, and apply the GOT4.7 ocean tide model for both dynamical ocean tide modeling and for ocean loading. The new TOPEX orbits have a mean SLR fit of 1.79 cm compared to 2.21 cm for the MGDR-B orbits. These new TOPEX orbits agree radially with independent SLR/crossover orbits at 0.70 cm RMS, and the orbit accuracy is estimated at 1.5–2.0 cm RMS over the entire TOPEX time series. The recomputed Jason-1 orbits agree radially with the Jason-1 GDR-C orbits at 1.08 cm RMS. The GSFC SLR/DORIS dynamic and reduced-dynamic orbits for Jason-2 agree radially with independent orbits from the CNES and JPL at 0.70–1.06 cm RMS. Applying these new orbits, and using the latest altimeter corrections for TOPEX, Jason-1, and Jason-2 from September 1992 to May 2009, we find a global rate in mean sea level of 3.0 + 0.4 mm/yr. Numéro de notice : A2010-564 Affiliation des auteurs : IGN+Ext (1940-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2010.05.007 Date de publication en ligne : 13/05/2010 En ligne : https://doi.org/10.1016/j.asr.2010.05.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30756
in Advances in space research > vol 46 n° 12 (15/12/2010) . - pp 1513 - 1540[article]Precision orbit determination standards for the Jason series of altimeter missions / L. Cerri in Marine geodesy, vol 33 suppl 1 (August 2010)PermalinkAnalytical solar radiation pressure modelling for GLONASS using a pixel array / Marek Ziebart in Journal of geodesy, vol 75 n° 11 (November 2001)Permalink