Journal of geodesy . vol 89 n° 7Paru le : 01/07/2015 |
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Ajouter le résultat dans votre panierAsynchronous RTK precise DGNSS positioning method for deriving a low-latency high-rate output / Zhang Liang in Journal of geodesy, vol 89 n° 7 (July 2015)
[article]
Titre : Asynchronous RTK precise DGNSS positioning method for deriving a low-latency high-rate output Type de document : Article/Communication Auteurs : Zhang Liang, Auteur ; Lv Hanfeng, Auteur ; Wang Dingjie, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 641 - 653 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] paramètre de temps
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement différentiel
[Termes IGN] positionnement par GNSS
[Termes IGN] station GNSS
[Termes IGN] synchronisation
[Termes IGN] transmission de donnéesRésumé : (auteur) Low-latency high-rate (>1 Hz) precise real-time kinematic (RTK) can be applied in high-speed scenarios such as aircraft automatic landing, precise agriculture and intelligent vehicle. The classic synchronous RTK (SRTK) precise differential GNSS (DGNSS) positioning technology, however, is not able to obtain a low-latency high-rate output for the rover receiver because of long data link transmission time delays (DLTTD) from the reference receiver. To overcome the long DLTTD, this paper proposes an asynchronous real-time kinematic (ARTK) method using asynchronous observations from two receivers. The asynchronous observation model (AOM) is developed based on undifferenced carrier phase observation equations of the two receivers at different epochs with short baseline. The ephemeris error and atmosphere delay are the possible main error sources on positioning accuracy in this model, and they are analyzed theoretically. In a short DLTTD and during a period of quiet ionosphere activity, the main error sources decreasing positioning accuracy are satellite orbital errors: the “inverted ephemeris error” and the integration of satellite velocity error which increase linearly along with DLTTD. The cycle slip of asynchronous double-differencing carrier phase is detected by TurboEdit method and repaired by the additional ambiguity parameter method. The AOM can deal with synchronous observation model (SOM) and achieve precise positioning solution with synchronous observations as well, since the SOM is only a specific case of AOM. The proposed method not only can reduce the cost of data collection and transmission, but can also support the mobile phone network data link transfer mode for the data of the reference receiver. This method can avoid data synchronizing process besides ambiguity initialization step, which is very convenient for real-time navigation of vehicles. The static and kinematic experiment results show that this method achieves 20 Hz or even higher rate output in real time. The ARTK positioning accuracy is better and more robust than the combination of phase difference over time (PDOT) and SRTK method at a high rate. The ARTK positioning accuracy is equivalent to SRTK solution when the DLTTD is 0.5 s, and centimeter level accuracy can be achieved even when DLTTD is 15 s. Numéro de notice : A2015-353 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0803-7 Date de publication en ligne : 15/03/2015 En ligne : http://dx.doi.org/10.1007/s00190-015-0803-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76776
in Journal of geodesy > vol 89 n° 7 (July 2015) . - pp 641 - 653[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]Determination of the local tie vector between the VLBI and GNSS reference points at Onsala using GPS measurements / Tong Ning in Journal of geodesy, vol 89 n° 7 (July 2015)
[article]
Titre : Determination of the local tie vector between the VLBI and GNSS reference points at Onsala using GPS measurements Type de document : Article/Communication Auteurs : Tong Ning, Auteur ; Rüdiger Haas, Auteur ; Gunnar Elgered, Auteur Année de publication : 2015 Article en page(s) : pp 711 - 723 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] co-positionnement
[Termes IGN] données GPS
[Termes IGN] données ITGB
[Termes IGN] écart type
[Termes IGN] point de liaison (géodésie)
[Termes IGN] point géodésique
[Termes IGN] précision millimétrique
[Termes IGN] SuèdeRésumé : (auteur) Two gimbal-mounted GNSS antennas were installed on each side of the radome-enclosed 20 m VLBI radio telescope at the Onsala Space Observatory. GPS data with a 1 Hz sampling rate were recorded for five semi-kinematic and four kinematic observing campaigns. These GPS data were analysed together with data from the IGS station ONSA with an in-house Matlab-based GPS software package, using the double-difference analysis strategy. The coordinates of the GNSS antennas on the telescope were estimated for different observation angles of the telescope, at specific epochs, and used to calculate the geodetic reference point of the telescope. The local tie vector between the VLBI and the ONSA GNSS reference points in a geocentric reference frame was hence obtained. The two different types of observing campaigns gave consistent results of the estimated local tie vector and the axis offset of the telescope. The estimated local tie vector obtained from all nine campaigns gave standard deviations of 1.5, 1.0, and 2.9 mm for the geocentric X, Y, and Z components, respectively. The result of the estimated axis offset of the VLBI telescope shows a difference of 0.3 mm, with a standard deviation of 1.9 mm, with respect to a reference value obtained by two local surveys carried out in 2002 and 2008. Our results show that the presented method can be used as a complement to the more accurate but more labour intensive classical geodetic surveys to continuously monitor the local tie at co-location stations with an accuracy of a few millimetres Numéro de notice : A2015-355 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0809-1 Date de publication en ligne : 05/04/2015 En ligne : https://doi.org/10.1007/s00190-015-0809-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76778
in Journal of geodesy > vol 89 n° 7 (July 2015) . - pp 711 - 723[article]Assessment of high-rate GPS using a single-axis shake table / Simon Häberling in Journal of geodesy, vol 89 n° 7 (July 2015)
[article]
Titre : Assessment of high-rate GPS using a single-axis shake table Type de document : Article/Communication Auteurs : Simon Häberling, Auteur ; Markus Rothacher, Auteur ; Y. Zhang, Auteur Année de publication : 2015 Article en page(s) : pp 697 - 709 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] antenne GNSS
[Termes IGN] bruit thermique
[Termes IGN] phase
[Termes IGN] réalité de terrain
[Termes IGN] récepteur GNSS
[Termes IGN] sismographeRésumé : (auteur) The developments in GNSS receiver and antenna technologies, especially the increased sampling rate up to 100 sps, open up the possibility to measure high-rate earthquake ground motions with GNSS. In this paper we focus on the GPS errors in the frequency band above 1 Hz. The dominant error sources are mainly the carrier phase jitter caused by thermal noise and the stress error caused by the dynamics, e.g. antenna motions. To generate a large set of different motions, we used a single-axis shake table, where a GNSS antenna and a strong motion seismometer were mounted with a well-known ground truth. The generated motions were recorded with three different GNSS receivers with sampling rates up to 100 sps and different receiver baseband parameters. The baseband parameters directly dictate the carrier phase jitter and the correlations between subsequent epochs. A narrow loop filter bandwidth keeps the carrier phase jitter on a low level, but has an extreme impact on the receiver response for motions above 1 Hz. The amplitudes above 3 Hz are overestimated up to 50 % or reduced by well over half. The corresponding phase errors are between 30 and 90 degrees. Compared to the GNSS receiver response, the strong motion seismometer measurements do not show any amplitude or phase variations for the frequency range from 1 to 20 Hz. Due to the large errors for dynamic GNSS measurements, it is essential to account for the baseband parameters of the GNSS receivers if high-rate GNSS is to become a valuable tool for seismic displacement measurements above 1 Hz. Fortunately, the receiver response can be corrected by an inverse filter if the baseband parameters are known. Numéro de notice : A2015-356 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0808-2 En ligne : https://doi.org/10.1007/s00190-015-0808-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76782
in Journal of geodesy > vol 89 n° 7 (July 2015) . - pp 697 - 709[article]