Centre de documentation
scientifique

An assessment of wide-lane ambiguity resolution methods for multi-frequency multi-GNSS precise point positioning / Viet Duong in Survey review, vol 52 n° 374 (August 2020)  

Public [article]  inSurvey review > vol 52 n° 374 (August 2020) . - pp 442 - 453 Titre : An assessment of wide-lane ambiguity resolution methods for multi-frequency multi-GNSS precise point positioning Type de document : Article/Communication Auteurs : Viet Duong, Auteur ; Ken Harima, Auteur ; Suelynn Choy, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 442 - 453 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] combinaison linéaire [Termes IGN] délai d'obtention de la première position [Termes IGN] fréquence multiple [Termes IGN] mesurage de phase [Termes IGN] mesurage par GNSS [Termes IGN] phase [Termes IGN] positionnement par GNSS [Termes IGN] positionnement ponctuel précis [Termes IGN] résolution d'ambiguïté [Termes IGN] station GNSS [Termes IGN] taux d'échantillonnage Résumé : (auteur) We assess the time-to-first-fix (TTFF) and the ambiguity fixing rate of two PPP wide-lane ambiguity resolution (WL-AR) methods, namely the geometry-based and ionospheric-free (GB-IF) method, and the geometry-free and ionospheric-free (GF-IF) method. First, an optimal GF-IF WL linear combination is selected based on the ratio between the code and carrier phase measurement noise (RT). Then, the relation between ambiguity variance and satellite geometry in the GB-IF WL-AR is investigated. Both simulated and real data from 31 GNSS stations over 37 consecutive days in 2017 were used. Numerical results show that the GF-IF WL-AR method has shorter TTFF and higher ambiguity fixing rate compared to the GB-IF method when RT≤150. However, when RT≥150, the GB-IF method outperforms the GF-IF method. Depending on RT values used, 2–10 min would be required to resolve the WL ambiguities when using GNSS measurements with one second sampling rate. Numéro de notice : A2020-518 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2019.1634339 Date de publication en ligne : 02/07/2019 En ligne : https://doi.org/10.1080/00396265.2019.1634339 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95678 [article]

An investigation into the performance of real-time GPS + GLONASS Precise Point Positioning (PPP) in New Zealand / Ken Harima in Journal of applied geodesy, vol 11 n° 3 (September 2017)  

Public [article]  inJournal of applied geodesy > vol 11 n° 3 (September 2017) . - pp 185 - 196 Titre : An investigation into the performance of real-time GPS + GLONASS Precise Point Positioning (PPP) in New Zealand Type de document : Article/Communication Auteurs : Ken Harima, Auteur ; Suelynn Choy, Auteur ; Chris Rizos, Auteur ; Satoshi Kogure, Auteur Année de publication : 2017 Article en page(s) : pp 185 - 196 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] données GNSS [Termes IGN] Nouvelle-Zélande [Termes IGN] positionnement par GLONASS [Termes IGN] positionnement par GPS [Termes IGN] positionnement ponctuel précis [Termes IGN] Quasi-Zenith Satellite System [Termes IGN] système d'extension [Termes IGN] temps réel Résumé : (Auteur) This paper presents an investigation into the performance of real-time Global Navigation Satellite Systems (GNSS) Precise Point Positioning (PPP) in New Zealand. The motivation of the research is to evaluate the feasibility of using PPP technique and a satellite based augmentation system such as the Japanese Quasi-Zenith Satellite System (QZSS) to deliver a real-time precise positioning solution in support of a nation-wide high accuracy GNSS positioning coverage in New Zealand. Two IGS real-time correction streams are evaluated alongside with the PPP correction messages transmitted by the QZSS satellite known as MDC1. MDC1 corrections stream is generated by Japan Aerospace Exploration Agency (JAXA) using the Multi-GNSS Advanced Demonstration tool for Orbit and Clock Analysis (MADOCA) software and are currently transmitted in test mode by the QZSS satellite. The IGS real-time streams are the CLK9B real-time corrections stream generated by the French Centre National D’études Spatiales (CNES) using the PPP-Wizard software, and the CLK81 real-time corrections stream produced by GMV using their MagicGNSS software. GNSS data is collected from six New Zealand CORS stations operated by Land Information New Zealand (LINZ) over a one-week period in 2015. GPS and GLONASS measurements are processed in a real-time PPP mode using the satellite orbit and clock corrections from the real-time streams. The results show that positioning accuracies of 6 cm in horizontal component and 15 cm in vertical component can be achieved in real-time PPP. The real-time GPS+GLONASS PPP solution required 30 minutes to converge to within 10 cm horizontal positioning accuracy. Numéro de notice : A2017-571 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2016-0035 En ligne : https://doi.org/10.1515/jag-2016-0035 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86691 [article]

Uncovering common misconceptions in GNSS Precise Point Positioning and its future prospect / Suelynn Choy in GPS solutions, vol 21 n° 1 (January 2017)  

Public [article]  inGPS solutions > vol 21 n° 1 (January 2017) . - pp 13 - 22 Titre : Uncovering common misconceptions in GNSS Precise Point Positioning and its future prospect Type de document : Article/Communication Auteurs : Suelynn Choy, Auteur ; Sunil Bisnath, Auteur ; Chris Rizos, Auteur Année de publication : 2017 Article en page(s) : pp 13 - 22 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] positionnement ponctuel précis [Termes IGN] précision centimétrique [Termes IGN] prospective [Termes IGN] récepteur GNSS [Termes IGN] test de performance Résumé : (Auteur) Within the last decade, GNSS Precise Point Positioning (PPP) has generated unprecedented interest among the GNSS community and is being used for a number of scientific and commercial applications today. Similar to the conventional relative positioning technique, PPP could provide positioning solutions at centimeter-level precision by making use of the precise carrier phase measurements and high-accuracy satellite orbits and clock corrections provided by, for example, the International GNSS Service. The PPP technique is attractive as it is computationally efficient; it eliminates the need for simultaneous observations at both the reference and rover receivers; it also eliminates the needs for the rover receiver to operate within the vicinity of the reference receiver; and it provides homogenous positioning quality within a consistent global frame anywhere in the world with a single GNSS receiver. Although PPP has definite advantages for many applications, its merits and widespread adoption are significantly limited by the long convergence time, which restricts the use of the PPP technique for many real-time GNSS applications. We provide an overview of the current performance of PPP as well as attempt to address some of the common misconceptions of this positioning technique—considered by many as the future of satellite positioning and navigation. Given the upcoming modernization and deployment of GNSS satellites over the next few years, it would be appropriate to address the potential impacts of these signals and constellations on the future prospect of PPP. Numéro de notice : A2017-012 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-016-0545-x En ligne : http://dx.doi.org/10.1007/s10291-016-0545-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83934 [article]

Application of satellite navigation system for emergency warning and alerting / Suelynn Choy in Computers, Environment and Urban Systems, vol 58 (July 2016)  

Public [article]  inComputers, Environment and Urban Systems > vol 58 (July 2016) . - pp 12 - 18 Titre : Application of satellite navigation system for emergency warning and alerting Type de document : Article/Communication Auteurs : Suelynn Choy, Auteur ; John Handmer, Auteur ; Joshua Whittaker, Auteur ; Yuki Shinohara, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 12 - 18 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] Australie [Termes IGN] gestion de crise [Termes IGN] Japon [Termes IGN] message d'alerte [Termes IGN] Quasi-Zenith Satellite System [Termes IGN] téléphonie mobile Résumé : (auteur) One of the key responsibilities of any government is to communicate and disseminate safety information and warnings to the general public in case of an emergency. Traditionally, warnings are issued by the government through a broadcast approach using communication channels such as TV and radio. However this monopolistic approach is now challenged by new technologies and media capable of providing individualised warnings to personal mobile devices. Location-based emergency services and mobile alerts are becoming increasingly prevalent in the provision of emergency warnings. These new modes of emergency services have been adopted by several countries worldwide including Australia. One example is the Australian National Emergency Alert (EA) which is a telephone-based service enhanced with location-based capabilities. This paper introduces the concept of applying global satellite navigation systems such as the Japanese satellite system in the domain of emergency warning and alerting. The Japanese satellite warning system can be tailored to transmit real-time location-based emergency warnings to people's mobile devices while not being constrained by the limitations of ground-based communication technologies. A key advantage of satellite based communication is its high resilience to communication network overload and failure of ground systems and network infrastructure during a disaster. This enables people to obtain necessary information anywhere (outdoor) and anytime during times of disaster. A satellite-based warning system could also be integrated with existing warning services and be used as a complementary technology. This paper examines opportunities and challenges for using satellite navigation systems to deliver warnings and safety messages during emergencies and disasters. Numéro de notice : A2016-403 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.compenvurbsys.2016.03.003 Date de publication en ligne : 01/04/2016 En ligne : http://dx.doi.org/10.1016/j.compenvurbsys.2016.03.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81218 [article]