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CODE’s new solar radiation pressure model for GNSS orbit determination / Daniel Arnold in Journal of geodesy, vol 89 n° 8 (August 2015)
[article]
Titre : CODE’s new solar radiation pressure model for GNSS orbit determination Type de document : Article/Communication Auteurs : Daniel Arnold, Auteur ; Michael Meindl, Auteur ; Gerhard Beutler, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 775 - 791 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Technologies spatiales
[Termes IGN] géocentre
[Termes IGN] International GNSS Service
[Termes IGN] modèle d'orbite
[Termes IGN] orbitographie
[Termes IGN] rayonnement solaire
[Termes IGN] récepteur GLONASS
[Termes IGN] récepteur GPS
[Termes IGN] rotation de la TerreRésumé : (auteur) The Empirical CODE Orbit Model (ECOM) of the Center for Orbit Determination in Europe (CODE), which was developed in the early 1990s, is widely used in the International GNSS Service (IGS) community. For a rather long time, spurious spectral lines are known to exist in geophysical parameters, in particular in the Earth Rotation Parameters (ERPs) and in the estimated geocenter coordinates, which could recently be attributed to the ECOM. These effects grew creepingly with the increasing influence of the GLONASS system in recent years in the CODE analysis, which is based on a rigorous combination of GPS and GLONASS since May 2003. In a first step we show that the problems associated with the ECOM are to the largest extent caused by the GLONASS, which was reaching full deployment by the end of 2011. GPS-only, GLONASS-only, and combined GPS/GLONASS solutions using the observations in the years 2009–2011 of a global network of 92 combined GPS/GLONASS receivers were analyzed for this purpose. In a second step we review direct solar radiation pressure (SRP) models for GNSS satellites. We demonstrate that only even-order short-period harmonic perturbations acting along the direction Sun-satellite occur for GPS and GLONASS satellites, and only odd-order perturbations acting along the direction perpendicular to both, the vector Sun-satellite and the spacecraft’s solar panel axis. Based on this insight we assess in the third step the performance of four candidate orbit models for the future ECOM. The geocenter coordinates, the ERP differences w. r. t. the IERS 08 C04 series of ERPs, the misclosures for the midnight epochs of the daily orbital arcs, and scale parameters of Helmert transformations for station coordinates serve as quality criteria. The old and updated ECOM are validated in addition with satellite laser ranging (SLR) observations and by comparing the orbits to those of the IGS and other analysis centers. Based on all tests, we present a new extended ECOM which substantially reduces the spurious signals in the geocenter coordinate z (by about a factor of 2–6), reduces the orbit misclosures at the day boundaries by about 10 %, slightly improves the consistency of the estimated ERPs with those of the IERS 08 C04 Earth rotation series, and substantially reduces the systematics in the SLR validation of the GNSS orbits. Numéro de notice : A2015-376 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0814-4 Date de publication en ligne : 12/05/2015 En ligne : https://doi.org/10.1007/s00190-015-0814-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76854
in Journal of geodesy > vol 89 n° 8 (August 2015) . - pp 775 - 791[article]Using ionospheric corrections from the space-based augmentation systems for low earth orbiting satellites / Jeongrae Kim in GPS solutions, vol 19 n° 3 (July 2015)
[article]
Titre : Using ionospheric corrections from the space-based augmentation systems for low earth orbiting satellites Type de document : Article/Communication Auteurs : Jeongrae Kim, Auteur ; Young Jae, Auteur Année de publication : 2015 Article en page(s) : pp 423 - 431 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Technologies spatiales
[Termes IGN] correction ionosphérique
[Termes IGN] données GRACE
[Termes IGN] European Geostationary Navigation Overlay Service
[Termes IGN] orbite basse
[Termes IGN] orbitographie
[Termes IGN] signal GPS
[Termes IGN] système d'extension spatial
[Termes IGN] teneur totale en électrons
[Termes IGN] Wide Area Augmentation SystemRésumé : (auteur) For low earth orbit satellite global positioning systems (GPS) receivers, ionospheric delay corrections from space-based augmentation system (SBAS) can be considered for real-time use. Due to the different total electron contents between ground and low altitude orbits, a scaling factor is required to adjust the ionospheric corrections. After an analysis of the scale factor determination with GPS data from the NASA/DLR gravity recovery and climate experiment satellite is conducted, evaluations of WAAS, MSAS, and EGNOS ionospheric correction accuracies are performed. In terms of the ionospheric correction error in 2012, SBAS outperforms GPS broadcast with the reduction of 42 %. This SBAS ionospheric correction accuracy shows a high level of correlation with solar flux F10.7. Numéro de notice : A2015-462 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-014-0402-8 Date de publication en ligne : 22/08/2014 En ligne : https://doi.org/10.1007/s10291-014-0402-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77138
in GPS solutions > vol 19 n° 3 (July 2015) . - pp 423 - 431[article]The impact of common versus separate estimation of orbit parameters on GRACE gravity field solutions / U. Meyer in Journal of geodesy, vol 89 n° 7 (July 2015)
[article]
Titre : The impact of common versus separate estimation of orbit parameters on GRACE gravity field solutions Type de document : Article/Communication Auteurs : U. Meyer, Auteur ; Adrian Jäggi, Auteur ; Gerhard Beutler, Auteur ; Heike Bock, Auteur Année de publication : 2015 Article en page(s) : pp 685 - 696 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] données GRACE
[Termes IGN] élément orbital
[Termes IGN] orbitographie
[Termes IGN] paramètre de temps
[Termes IGN] propagation du signal
[Termes IGN] traitement du signalRésumé : (auteur) Gravity field parameters are usually determined from observations of the GRACE satellite mission together with arc-specific parameters in a generalized orbit determination process. When separating the estimation of gravity field parameters from the determination of the satellites’ orbits, correlations between orbit parameters and gravity field coefficients are ignored and the latter parameters are biased towards the a priori force model. We are thus confronted with a kind of hidden regularization. To decipher the underlying mechanisms, the Celestial Mechanics Approach is complemented by tools to modify the impact of the pseudo-stochastic arc-specific parameters on the normal equations level and to efficiently generate ensembles of solutions. By introducing a time variable a priori model and solving for hourly pseudo-stochastic accelerations, a significant reduction of noisy striping in the monthly solutions can be achieved. Setting up more frequent pseudo-stochastic parameters results in a further reduction of the noise, but also in a notable damping of the observed geophysical signals. To quantify the effect of the a priori model on the monthly solutions, the process of fixing the orbit parameters is replaced by an equivalent introduction of special pseudo-observations, i.e., by explicit regularization. The contribution of the thereby introduced a priori information is determined by a contribution analysis. The presented mechanism is valid universally. It may be used to separate any subset of parameters by pseudo-observations of a special design and to quantify the damage imposed on the solution. Numéro de notice : A2015-354 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0807-3 Date de publication en ligne : 29/03/2015 En ligne : https://doi.org/10.1007/s00190-015-0807-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76777
in Journal of geodesy > vol 89 n° 7 (July 2015) . - pp 685 - 696[article]Accuracy and reliability of multi-GNSS real-time precise positioning: GPS, GLONASS, BeiDou, and Galileo / Xinging Li in Journal of geodesy, vol 89 n° 6 (June 2015)
[article]
Titre : Accuracy and reliability of multi-GNSS real-time precise positioning: GPS, GLONASS, BeiDou, and Galileo Type de document : Article/Communication Auteurs : Xinging Li, Auteur ; Maorong Ge, Auteur ; Xiaolei Dai, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 607-635 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] fiabilité des données
[Termes IGN] orbitographie
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] précision du positionnement
[Termes IGN] signal BeiDou
[Termes IGN] signal Galileo
[Termes IGN] signal GLONASS
[Termes IGN] signal GPS
[Termes IGN] temps réelRésumé : (auteur) In this contribution, we present a GPS+GLONASS+BeiDou+Galileo four-system model to fully exploit the observations of all these four navigation satellite systems for real-time precise orbit determination, clock estimation and positioning. A rigorous multi-GNSS analysis is performed to achieve the best possible consistency by processing the observations from different GNSS together in one common parameter estimation procedure. Meanwhile, an efficient multi-GNSS real-time precise positioning service system is designed and demonstrated by using the multi-GNSS Experiment, BeiDou Experimental Tracking Network, and International GNSS Service networks including stations all over the world. The statistical analysis of the 6-h predicted orbits show that the radial and cross root mean square (RMS) values are smaller than 10 cm for BeiDou and Galileo, and smaller than 5 cm for both GLONASS and GPS satellites, respectively. The RMS values of the clock differences between real-time and batch-processed solutions for GPS satellites are about 0.10 ns, while the RMS values for BeiDou, Galileo and GLONASS are 0.13, 0.13 and 0.14 ns, respectively. The addition of the BeiDou, Galileo and GLONASS systems to the standard GPS-only processing, reduces the convergence time almost by 70 %, while the positioning accuracy is improved by about 25 %. Some outliers in the GPS-only solutions vanish when multi-GNSS observations are processed simultaneous. The availability and reliability of GPS precise positioning decrease dramatically as the elevation cutoff increases. However, the accuracy of multi-GNSS precise point positioning (PPP) is hardly decreased and few centimeter are still achievable in the horizontal components even with 40∘ elevation cutoff. At 30∘ and 40∘ elevation cutoffs, the availability rates of GPS-only solution drop significantly to only around 70 and 40 %, respectively. However, multi-GNSS PPP can provide precise position estimates continuously (availability rate is more than 99.5 %) even up to 40∘ elevation cutoff (e.g., in urban canyons). Numéro de notice : A2015-352 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0802-8 Date de publication en ligne : 14/03/2015 En ligne : https://doi.org/10.1007/s00190-015-0802-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76760
in Journal of geodesy > vol 89 n° 6 (June 2015) . - pp 607-635[article]Estimating the short-term stability of in-orbit GNSS clocks : Following launch on GEO/GSO satellites / Dhaval Upadhyay in Inside GNSS, vol 10 n° 3 (May - June 2015)
[article]
Titre : Estimating the short-term stability of in-orbit GNSS clocks : Following launch on GEO/GSO satellites Type de document : Article/Communication Auteurs : Dhaval Upadhyay, Auteur ; Kriti Khatri, Auteur ; et al., Auteur Année de publication : 2015 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] éphémérides de satellite
[Termes IGN] horloge atomique
[Termes IGN] orbite géostationnaireRésumé : (éditeur) An engineering team proposes a method for determining the time of atomic clocks onboard satellites in geosynchronous and geostationary orbits when precise ephemeris data from ground monitoring stations are unavailable during initial checkout following launch. Numéro de notice : A2015-252 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.insidegnss.com/node/4503 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76296
in Inside GNSS > vol 10 n° 3 (May - June 2015)[article]Enhanced solar radiation pressure modeling for Galileo satellites / Oliver Montenbruck in Journal of geodesy, vol 89 n° 3 (March 2015)PermalinkImpact of the atmospheric drag on Starlette, Stella, Ajisai, and Lares Orbits / Krzysztof Sosnica in Artificial satellites, vol 50 n° 1 (March 2015)PermalinkGalileo orbit determination using combined GNSS and SLR observations / Stefan Hackel in GPS solutions, vol 19 n° 1 (January 2015)PermalinkPositioning configurations with the lowest GDOP and their classification / Shuqiang Xue in Journal of geodesy, vol 89 n° 1 (January 2015)PermalinkOrbit computation of the TELECOM-2D satellite with a genetic algorithm / Florent Deleflie in Proceedings of the International astronomical union, vol 9 S310 (Juillet 2014)PermalinkPermalinkEstimated SLR station position and network frame sensitivity to time-varying gravity / Nikita P. Zelensky in Journal of geodesy, vol 88 n° 6 (June 2014)PermalinkA near-real-time automatic orbit determination system for COSMIC and its follow-on satellite mission: analysis of orbit and clock errors on radio occultation / Yi-Shan Li in IEEE Transactions on geoscience and remote sensing, vol 52 n° 6 Tome 1 (June 2014)PermalinkPermalinkReal-time GNSS activities at ESA: navigation support office provides services for IGS and users / Werner Enderle in GPS world, vol 24 n° 11 (November 2013)Permalink