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Auteur Manoj Deo |
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Precise 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)
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Titre : Precise point positioning with decimetre accuracy using wide-lane ambiguities and triple-frequency GNSS data Type de document : Article/Communication Auteurs : Manoj Deo, Auteur ; Ahmed El-Mowafy, Auteur Année de publication : 2020 Article en page(s) : pp 263 – 284 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] ambiguïté entière
[Termes IGN] bruit atmosphérique
[Termes IGN] combinaison linéaire
[Termes IGN] données GNSS
[Termes IGN] phase
[Termes IGN] positionnement ponctuel précis
[Termes IGN] triple différenceRésumé : (auteur) This paper proposes precise point positioning (PPP) methods that offer an accuracy of a few decimetres (dm) with triple frequency GNSS data. Firstly, an enhanced triple frequency linear combination is presented for rapid fixing of the extra wide-lane (EWL) and wide-lane (WL) ambiguities for GPS, Beidou-2 and Galileo. This has improved performance compared to the Melbourne-Wübbena (MW) linear combination, and has 6.7 % lower measurement noise for the GPS L1/L2 signals, 12.7 % for L1/L5 and 0.7 % for L2/L5. Analysis with tested data showed a 5–6 % reduction in time required to fix the N21 and N51 ambiguities. Once the EWL/WL ambiguities are fixed with the proposed linear combinations, three methods are presented that aim to provide positioning accuracy of a few dm. In the first approach, the three EWL/WL ambiguities in their respective phase equations are used to derive a low-noise ionosphere-free (IF) linear combination. The second method uses a low noise IF combination with two carrier-phase EWL/WL equations and a single pseudorange measurement. The third method uses a low noise IF combination with a single carrier phase EWL equation and two pseudorange measurements. These proposed methods can provide dm level positioning accuracy if carrier phase measurements with mm precision is tracked by the receiver. When comparing these combinations with a combination proposed in [], it is found that superior performance is achieved with the third method when carrier phase noise is >5–6 mm for GPS and Beidou-2 and >2–3 mm for Galileo. This model only requires the EWL ambiguity to be fixed which typically takes just one epoch of data. Thus, the user achieves instant decimetre level PPP accuracy. Numéro de notice : A2020-466 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jag-2019-0068 Date de publication en ligne : 11/03/2020 En ligne : https://doi.org/10.1515/jag-2019-0068 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95432
in Journal of applied geodesy > vol 14 n° 3 (July 2020) . - pp 263 – 284[article]Maintaining real-time precise point positioning during outages of orbit and clock corrections / Ahmed El-Mowafy in GPS solutions, vol 21 n° 3 (July 2017)
[article]
Titre : Maintaining real-time precise point positioning during outages of orbit and clock corrections Type de document : Article/Communication Auteurs : Ahmed El-Mowafy, Auteur ; Manoj Deo, Auteur ; Nobuaki Kubo, Auteur Année de publication : 2017 Article en page(s) : pp 937 – 947 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] horloge
[Termes IGN] International GNSS Service
[Termes IGN] international GPS service for geodynamics
[Termes IGN] interruption du signal
[Termes IGN] orbitographie
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] précision décimétrique
[Termes IGN] prévisionRésumé : (auteur) The precise point positioning (PPP) is a popular positioning technique that is dependent on the use of precise orbits and clock corrections. One serious problem for real-time PPP applications such as natural hazard early warning systems and hydrographic surveying is when a sudden communication break takes place resulting in a discontinuity in receiving these orbit and clock corrections for a period that may extend from a few minutes to hours. A method is presented to maintain real-time PPP with 3D accuracy less than a decimeter when such a break takes place. We focus on the open-access International GNSS Service (IGS) real-time service (RTS) products and propose predicting the precise orbit and clock corrections as time series. For a short corrections outage of a few minutes, we predict the IGS-RTS orbits using a high-order polynomial, and for longer outages up to 3 h, the most recent IGS ultra-rapid orbits are used. The IGS-RTS clock corrections are predicted using a second-order polynomial and sinusoidal terms. The model parameters are estimated sequentially using a sliding time window such that they are available when needed. The prediction model of the clock correction is built based on the analysis of their properties, including their temporal behavior and stability. Evaluation of the proposed method in static and kinematic testing shows that positioning precision of less than 10 cm can be maintained for up to 2 h after the break. When PPP re-initialization is needed during the break, the solution convergence time increases; however, positioning precision remains less than a decimeter after convergence. Numéro de notice : A2017-442 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-016-0583-4 En ligne : https://doi.org/10.1007/s10291-016-0583-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86360
in GPS solutions > vol 21 n° 3 (July 2017) . - pp 937 – 947[article]