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Auteur Ant Sibthorpe |
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Affiner la recherche Interroger des sources externesGipsyX/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)
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 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]
Titre : An evaluation of solar radiation pressure strategies for the GPS constellation Type de document : Article/Communication Auteurs : Ant Sibthorpe, Auteur ; Willy I. Bertiger, Auteur ; Shailen Desai, Auteur ; et al., Auteur Année de publication : 2011 Article en page(s) : pp 505 - 517 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] analyse comparative
[Termes IGN] constellation GPS
[Termes IGN] données TLS (télémétrie)
[Termes IGN] GIPSY-OASIS
[Termes IGN] international GPS service for geodynamics
[Termes IGN] orbitographie
[Termes IGN] rayonnement solaire
[Termes IGN] résolution d'ambiguïtéRésumé : (Auteur) The subtle effects of different Global Positioning System (GPS) satellite force models are becoming apparent now that mature processing strategies are reaching new levels of accuracy and precision. For this paper, we tested several approaches to solar radiation pressure (SRP) modeling that are commonly used by International GNSS Service (IGS) analysis centers. These include the GPS Solar Pressure Model (GSPM; Bar-Sever and Kuang in The Interplanetary Network Progress Report 42-160, 2005) and variants of the so-called DYB model (Springer et al. in Adv Space Res 23:673–676, 1999). Our results show that currently observed differences between GPS orbit solutions from the various IGS analysis centers are in large part explained by differences between their respective approaches to modeling SRP. DYB-based strategies typically generate orbit solutions that have the smallest differences with respect to the IGS final combined solution, largely because the DYB approach is most commonly used by the contributing analysis centers. However, various internal and external metrics, including ambiguity resolution statistics and satellite laser ranging observations, support continued use of the GSPM-based approach for precise orbit determination of the GPS constellation, at least when using the GIPSY-OASIS software. Numéro de notice : A2011-358 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0450-6 Date de publication en ligne : 19/02/2011 En ligne : https://doi.org/10.1007/s00190-011-0450-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31137
in Journal of geodesy > vol 85 n° 8 (August 2011) . - pp 505 - 517[article]Réservation
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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 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]
Titre : Improving DORIS geocenter time series using an empirical rescaling of solar radiation pressure models Type de document : Article/Communication Auteurs : Marie-Line Gobinddass Année de publication : 2009 Article en page(s) : pp 1279 - 1287 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données DORIS
[Termes IGN] erreur systématiqueRésumé : (auteur) Even if Satellite Laser Ranging (SLR) remains the fundamental technique for geocenter monitoring, DORIS can also determine this geophysical parameter. Gobinddass et al. (2009) found that part of the systematic errors at 118 days and 1 year can be significantly reduced by rescaling the current solar radiation pressure models using satellite-dependent empirical models. Here we extend this study to all DORIS satellites and propose a complete set of empirical solar radiation parameter coefficients. A specific problem related to SPOT-5 solar panel realignment is also detected and explained. New DORIS geocenter solutions now show a much better agreement in amplitude with independent SLR solutions and with recent geophysical models. Finally, the impact of this refined DORIS data strategy is discussed in terms of Z-geocenter monitoring as well as for other geodetic products (altitude of high latitude station such as Thule in Greenland) and Precise Orbit Determination. After reprocessing the full 1993.0-2008.0 DORIS data set, we confirm that the proposed strategy allows a significant reduction of systematic errors at periods of 118 days and 1 year (up to 20 mm), especially for the most recent data after 2002.5, when more DORIS satellites are available for geodetic purposes. Numéro de notice : A2009-609 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2009.08.004 Date de publication en ligne : 08/08/2009 En ligne : https://doi.org/10.1016/j.asr.2009.08.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102372
in Advances in space research > vol 44 n° 11 (1 December 2009) . - pp 1279 - 1287[article]
Titre : Systematic biases in DORIS-derived geocenter time series related to solar radiation pressure mis-modeling Type de document : Article/Communication Auteurs : Marie-Line Gobinddass Année de publication : 2009 Article en page(s) : pp 849 - 858 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données DORIS
[Termes IGN] erreur systématique
[Termes IGN] rayonnement solaire
[Termes IGN] série temporelleRésumé : (auteur) As any satellite geodesy technique, DORIS can monitor geocenter variations associated to mass changes within the Earth–Atmosphere–Continental hydrosphere–Oceans system. However, especially for the Z-component, corresponding to a translation of the Earth along its rotation axis, the estimated geocenter is usually affected by large systematic errors of unknown cause. By reprocessing old DORIS data, and by analyzing single satellite solutions in the frequency domain, we show that some of these errors are satellite-dependent and related to the current DORIS orbit determination strategy. In particular, a better handling of solar pressure radiation effects on SPOT-2 and TOPEX satellites is proposed which removes a large part of such artifacts. By empirically multiplying the current solar pressure model with a single coefficient (1.03 for TOPEX/Poseidon after 1993.57, and 0.96 before; and 1.08 for SPOT-2) estimated over a long time period, we can improve the measurement noise of the Z-geocenter component from 47.5 to 30.4 mm for the RMS and from 35 to 6 mm for the amplitude of the annual signal. However, the estimated SRP coefficient for SPOT-2 presents greater temporal variability, indicating that a new, dedicated solar radiation pressure model is still needed for precise geodetic applications. In addition, for the TOPEX satellite, a clear discontinuity of unknown cause is also detected on July 27, 1993. Numéro de notice : A2009-599 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-009-0303-8 Date de publication en ligne : 24/01/2009 En ligne : https://doi.org/10.1007/s00190-009-0303-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102417
in Journal of geodesy > vol 83 n° 9 (September 2009) . - pp 849 - 858[article]
