2020 European Navigation Conference (ENC)最新文献

{"title":"Spaceborne GNSS-Receiver Heritage Leveraged on New Space","authors":"Markus Schütz, Stefan Zehetmayer, K. Zajac, J. Borany, M. Laabs, F. Zangerl, Roman Zangl, D. Plettemeier, M. Sust","doi":"10.23919/ENC48637.2020.9317497","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317497","url":null,"abstract":"Global Navigation Satellite System receivers have become inevitable for space missions. Although space qualified components and proven receiver concepts with space heritage exist, dedicated products are required for NewSpace applications due to cost reasons. On the one hand the NewSpace paradigm asks for low cost, mass, size and power consumption, suggesting usage of commercial off-the-shelf technology and minimal features, while on the other hand applications such as telecom mega-constellations and innovative earth observation missions simultaneously using many small satellites require superior navigation performance. Relying on such performance results in full dependence on receiver reliability and availability. Based on the analysis of current traditional as well as NewSpace GNSS-receiver approaches relative to the underlying applications, a GNSS-receiver product platform dedicated to NewSpace, but aiming at leveraging traditional space experience and at preserving flight heritage is presented.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"176 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134161395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of GNSS Spoofing using NMEA Messages","authors":"Dong-Kyeong Lee, D. Miralles, D. Akos, A. Konovaltsev, L. Kurz, S. Lo, Filip Nedelkov","doi":"10.23919/ENC48637.2020.9317470","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317470","url":null,"abstract":"Many devices are dependent on the positioning, velocity, and time information provided by Global Navigation Satellite Systems (GNSS) receivers. Although the accuracy and integrity of GNSS receivers have improved over the years, the susceptibility of the receivers to signal interferences such as GNSS jamming and spoofing remains a significant issue to various systems. In this study, the authors successfully spoof a commercial u-blox GNSS receiver, and the GNSS receivers inside multiple Android smartphones, and an iPhone. In addition, it is shown that the spoofing of GNSS receivers is sufficient to successfully spoof the fused location engines of the smartphones which use not only GNSS, but a combination of other location sources such as network positioning and inertial sensors. Following the spoofing, the authors suggest how the National Marine Electronics Association (NMEA) messages provided by the GNSS receivers can be utilized to detect instances of spoofing and identify suspicious potentially spoofed satellite signals. The use of NMEA messages instead of raw GNSS measurements to detect potential GNSS spoofing allows us to assess the utility of the currently available resources, and bypass large computation loads required to obtain and process raw measurements.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132680223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial Analysis of the Correlation between Scintillation Parameters and MP&ROTI","authors":"Chendong Li, C. Hancock, S. V. Veettil, Chong You","doi":"10.23919/ENC48637.2020.9317345","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317345","url":null,"abstract":"Ionospheric scintillation, often described using the parameters S4 and σφ is one of the most severe error sources that influences the operation of Global Navigation Satellite System (GNSS). However, these two parameters can only be generated by scintillation monitoring receivers that have limited numbers around the world. This paper aims to investigate the correlation between scintillation parameters and MP&ROTI (multipath & rate of total electron content index) so that scintillation events can be represented by parameters that can be obtained from standard receivers in order to research on scintillation from a different perspective. Furthermore the utilization of these parameters as a means of identifying scintillation events could facilitate the use of archived GNSS data from non-scintillation receivers for improved ionosphere research. GPS data of one day with strong scintillation is obtained from the station, SAOOP located in Sao Paolo, Brazil. Time series plots and 2-D maps of all the parameters are utilized to respectively observe the general and spatial relationship between the scintillation parameters and other parameters. Furthermore, structural similarity (SSIM) generated between 2-D maps of different parameters are applied to confirm the spatial similarity. The results show that the high correlations between scintillation parameters and MP&ROTI are confirmed temporally and spatially respectively based time series plots and 2-D maps.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133821151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tropospheric delays derived from ground meteorological parameters: comparison between machine learning and empirical model approaches","authors":"Luc Miotti, Endrit Shehaj, A. Geiger, Stefano D'aronco, J. D. Wegner, G. Moeller, M. Rothacher","doi":"10.23919/ENC48637.2020.9317442","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317442","url":null,"abstract":"High spatia-temporal variability of atmospheric water vapor is directly reflected in the tropospheric pathdelays that microwave satellite signals experience. The so-called zenith total delays (ZTDs) need to be estimated in case of Global Navigation Satellite Systems (GNSS). Usually, models describe the ZTD with three meteorological parameters measured on ground: pressure, temperature and partial water vapor pressure. However, these models are determined empirically and it is especially a struggle to accurately determine the delay caused by the water vapor (wet delay) from meteorological data. In this work, we provide an alternative approach of estimating the tropospheric path delay using machine learning (ML) algorithms. During the last two decades machine learning algorithms have become widely used in many fields of science and engineering. Therefore, a large amount of time series of ZTDs and meteorological data and the successful applicability of machine learning to various applications are the main motivation behind this work. Besides, we also investigated another approach to compute ZTDs, based on the well-known Saastamoinen model [Saastamoinen, 1973], after interpolating the meteorological parameters at GNSS sites. The idea behind this work is to genarate GNSS zenith pathdelays without nrocessing any GNSS data, but only using meteorological parameters. Therefore, GNSS zenith pathdelays from 72 permanent stations in Switzerland and meteorological data from the permanent SwissMetNet network (with over 120 stations) have been used for training and validation for a period of 11 years. The distribution of the sites all over Switzerland allows the network to be trained and validated with stations at different altitudes and with various meteorological conditions. The ML approach showed an overall accuracy of 1.6 cm in terms of standard deviation, with almost no bias. Moreover, results show that stations at higher altitudes can benefit more from this approach. Compared to the Saastamoinen model, it had an overall improvement of about 20%, with a much better estimation in summer periods, when the amount of water vapor is higher. This work is a contribution to using ML algorithms to compensate for atmospheric errors in GNSS signals, and to compare its capabilities with empirically derived models.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117274502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of non-idealities on GNSS meta-signals processing","authors":"Andrea Nardin, F. Dovis, B. Motella","doi":"10.23919/ENC48637.2020.9317365","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317365","url":null,"abstract":"This paper deals with the concept of GNSS meta-signal processing, defined as the coherent process of two GNSS signals, broadcast on different carriers, and treated as a single wideband signal. The purpose of the paper is twofold: to analyse the effects on non-idealities on the meta-signal components and to investigate alternative schemes for the actual implementation inside the receiver.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124724363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Framework to Classify Railway Track Areas According to Local GNSS Threats","authors":"Daniel Gerbeth, Omar García Crespillo, Fabio Pognante, A. Vennarini, A. Coluccia","doi":"10.23919/ENC48637.2020.9317368","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317368","url":null,"abstract":"In this paper we present a modular framework to classify railway track areas regarding the expected presence of local GNSS threats. This information might be critical for a safe signalling operation, for example to determine where virtual balises could be placed safely. We show first how different GNSS threats can be detected using dedicated detection algorithms and how these individual detection results can be then transformed from time to the track domain. An overall decision logic is subsequently used to identify an area as suitable or unsuitable for GNSS usage by combining all available GNSS data collected over the same track area. Finally, the framework implementation is evaluated with railway data obtained during a measurement campaign in Sardinia, Italy in 2019. Even though developed in the railway context, the presented framework architecture and methodology may be also considered to perform similar classification tasks for other means of transport.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125075363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multipath and NLOS detection based on the combination of CN0 values and a fish-eye camera","authors":"J. Marais, Syed Ali Kazim, Y. Cocheril, C. Meurie","doi":"10.23919/ENC48637.2020.9317408","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317408","url":null,"abstract":"For land transport environment and railways in particular, the main limits of GNSS signal exploitations for an accurate and safe positioning comes from the local environment surrounding the vehicle. Obstacles induce multipath and non-line of sight signal reception that need to be detected for railway line characterization or feared event mitigation. In this paper, we show that the use of two techniques based on CN0 and camera respectively, can help to detect and label faulty events along a trajectory. The methods have been applied on a test run performed during the ERSAT GGC project in Spain. This paper presents first the techniques, then an analysis of the detections for evaluation.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132851323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast Ionospheric Correction Algorithm for Galileo Single Frequency Users","authors":"M. M. Hoque, N. Jakowski, J. A. Cahuasquí","doi":"10.23919/ENC48637.2020.9317502","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317502","url":null,"abstract":"We propose an alternative ionospheric correction approach for single frequency Galileo users. In the proposed approach the broadcasted coefficients are used to drive the Neustrelitz Total Electron Content (TEC) Model (NTCM) instead of the standard Galileo ionosphere model NeQuick-G. The NTCM-based correction approach uses 12 model coefficients, the solar radio flux index F10 and a few empirically fixed parameters. The required TEC values can be computed at any location and time without using any spatial or temporal interpolation of parameters. This makes NTCM very fast running in operational applications. The presented approach performs well when fed with the same Az parameter as NeQuick-G. The global performance analysis with reference Vertical Total Electron Content (VTEC) data from the International GNSS Service (IGS) shows that the performance of the NTCM was better than that of NeQuick-G. A comparison with reference Slant TEC (STEC) data shows that there is no significant difference between both models performance in terms of residual statistics such as Root Mean Square (RMS), mean and Standard Deviation (STD). Here, an improved mapping function could even reduce corresponding errors when transforming NTCM derived VTEC to STEC values used for comparison. When comparing the computational time, it is found that the NTCM use is in average 65 times faster than the NeQuick-G operation.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"43 11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130488406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling Of The Delayed Ionospheric Response With The TIE-GCM Model","authors":"Erik Schmölter, J. Berdermann, C. Jacobi, N. Jakowski","doi":"10.23919/ENC48637.2020.9317355","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317355","url":null,"abstract":"In this study the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) is used to describe the delayed ionospheric response to solar Extreme Ultraviolet (EUV) radiation and its varying relation to solar and geomagnetic activity (e.g. stronger impact of the solar wind during winter season in the northern hemisphere). Long-term changes, at time scales longer than the 27-day solar rotation cycle, are analyzed and the dependence of the ionospheric delay on the solar activity is presented based on calculations at a chosen location in the mid-latitudes. Ionospheric delays of 2, 11 and 20 h can be correlated to the mean solar radio flux index (F10.7) values of 95, 115 and 135 sfu. In addition, a possible relation of the delayed ionospheric response with the geomagnetic activity is analyzed with TIE-GCM model runs, that estimate an ionospheric delay of 15 h for a corresponding Kp-index of≈ 0.91 and an ionospheric delay of 17 h for a corresponding Kp-index of ≈ 2.88 (during December). These differences are related to changes in electron temperature and ion velocity perpendicular to the geomagnetic field lines. The results suggest a significant impact of transport processes on the delayed ionospheric response.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"100 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120894180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global ARAIM for Dual Constellation - Design, Development and Experimentation","authors":"Joseph Griggs, D. Hagan, Urielle Houssou, A. Calabrese, Fernando Bravo Llano, G. F. Serrano, Emad Adridar, J. Montolio, Alex Ramonjoan, M. Reche","doi":"10.23919/ENC48637.2020.9317437","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317437","url":null,"abstract":"Advanced Receiver Autonomous Integrity Monitoring (ARAIM) is an enhancement to the traditional Global Positioning System (GPS) single frequency RAIM - an airborne receiver functionality that performs fault detection and exclusion on GPS satellites. The proliferation of Dual-Frequency, Multi-Constellation, (DFMC) Global Navigation Satellite System (GNSS) signals is an enabler for the conception, development, acceleration, standardisation and certification of the ARAIM technology within the aviation domain in order to achieve worldwide Localizer Performance with Vertical guidance to decision height of 200 feet (LPV-200) with vertical alert limit of 35 metres. The latter is a capability to support GNSS-based aircraft operations for all phases of flight. This paper presents the design, development and flight experimentation activities conducted within the framework of the project known as Global ARAIM for Dual-Constellation (GLAD). GLAD adopts and implements, as a prototype, the baseline ARAIM algorithm proposed by the Working Group C (WG-C) ARAIM Technical Subgroup (TSG) in a commercial grade Multi-Mode Receiver (MMR). Within the scope of the development, the impact of computational loading for the GNSS receiver is discussed, particularly related to the processing of the algorithm in order to manage the variation of probability information of GNSS satellites and constellation failures. The Integrity Support Message (ISM) forms the core of the ARAIM concept. It provides flexibility in varying satellite and/or constellation parameters to be used within the ARAIM algorithm at varying update rates. The generation of an ISM along with the means to do so are elaborated. To conclude this paper, the verification and flight experimentation plans and trials to validate Horizontal ARAIM (H-ARAIM) and Vertical ARAIM (V-ARAIM) offline are presented along with the results to assess the performance of ARAIM in support of Required Navigation Performance (RNP) 0.3 and LPV-200 requirements.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"458 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116771804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}