Reason-Resilience and security of geospatial data for critical infrastructures

Peer reviewe

Stand-alone and Hybrid Positioning using Asynchronous Pseudolites

Global navigation satellite system (GNSS) receivers are usually unable to achieve satisfactory performance in difficult environments, such as open-pit mines, urban canyons and indoors. Pseudolites have the potential to extend GNSS usage and significantly improve receiver performance in such environments by providing additional navigation signals. This also applies to asynchronous pseudolite systems, where different pseudolites operate in an independent way. Asynchronous pseudolite systems require, however, dedicated strategies in order to properly integrate GNSS and pseudolite measurements. In this paper, several asynchronous pseudolite/GNSS integration strategies are considered: loosely- and tightly-coupled approaches are developed and combined with pseudolite proximity and receiver signal strength (RSS)-based positioning. The performance of the approaches proposed has been tested in different scenarios, including static and kinematic conditions. The tests performed demonstrate that the methods developed are effective techniques for integrating heterogeneous measurements from different sources, such as asynchronous pseudolites and GNSS.JRC.G.5-Security technology assessmen

GNSS Radio Frequency Interference Monitoring from LEO Satellites: An In-Laboratory Prototype

The disruptive effect of radio frequency interference (RFI) on global navigation satellite system (GNSS) signals is well known, and in the last four decades, many have been investigated as countermeasures. Recently, low-Earth orbit (LEO) satellites have been looked at as a good opportunity for GNSS RFI monitoring, and the last five years have seen the proliferation of many commercial and academic initiatives. In this context, this paper proposes a new spaceborne system to detect, classify, and localize terrestrial GNSS RFI signals, particularly jamming and spoofing, for civil use. This paper presents the implementation of the RFI detection software module to be hosted on a nanosatellite. The whole development work is described, including the selection of both the target platform and the algorithms, the implementation, the detection performance evaluation, and the computational load analysis. Two are the implemented RFI detectors: the chi-square goodness-of-fit (GoF) algorithm for non-GNSS-like interference, e.g., chirp jamming, and the snapshot acquisition for GNSS-like interference, e.g., spoofing. Preliminary testing results in the presence of jamming and spoofing signals reveal promising detection capability in terms of sensitivity and highlight room to optimize the computational load, particularly for the snapshot-acquisition-based RFI detector

The smartphone-based offline indoor location competition at IPIN 2016: analysis and future work

This paper presents the analysis and discussion of the off-site localization competition track, which took place during the Seventh International Conference on Indoor Positioning and Indoor Navigation (IPIN 2016). Five international teams proposed different strategies for smartphone-based indoor positioning using the same reference data. The competitors were provided with several smartphone-collected signal datasets, some of which were used for training (known trajectories), and others for evaluating (unknown trajectories). The competition permits a coherent evaluation method of the competitors' estimations, where inside information to fine-tune their systems is not offered, and thus provides, in our opinion, a good starting point to introduce a fair comparison between the smartphone-based systems found in the literature. The methodology, experience, feedback from competitors and future working lines are described.We would like to thank Tecnalia Research & Innovation Foundation for sponsoring the competition track with an award for the winning team. We are also grateful to Francesco Potortì, Sangjoon Park, Jesús Ureña and Kyle O’Keefe for their invaluable help in promoting the IPIN competition and conference. Parts of this work was carried out with the financial support received from projects and grants: LORIS (TIN2012-38080-C04-04), TARSIUS (TIN2015-71564-C4-2-R (MINECO/FEDER)), SmartLoc (CSIC-PIE Ref.201450E011), “Metodologías avanzadas para el diseño, desarrollo, evaluación e integración de algoritmos de localización en interiores” (TIN2015-70202-P), REPNIN network (TEC2015-71426-REDT) and the José Castillejo mobility grant (CAS16/00072). The HFTS team has been supported in the frame of the German Federal Ministry of Education and Research programme “FHprofUnt2013” under contract 03FH035PB3 (Project SPIRIT). The UMinho team has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT — Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio

Off-line evaluation of mobile-centric indoor positioning systems: the experiences from the 2017 IPIN competition

The development of indoor positioning solutions using smartphones is a growing activity with an enormous potential for everyday life and professional applications. The research activities on this topic concentrate on the development of new positioning solutions that are tested in specific environments under their own evaluation metrics. To explore the real positioning quality of smartphone-based solutions and their capabilities for seamlessly adapting to different scenarios, it is needed to find fair evaluation frameworks. The design of competitions using extensive pre-recorded datasets is a valid way to generate open data for comparing the different solutions created by research teams. In this paper, we discuss the details of the 2017 IPIN indoor localization competition, the different datasets created, the teams participating in the event, and the results they obtained. We compare these results with other competition-based approaches (Microsoft and Perf-loc) and on-line evaluation web sites. The lessons learned by organising these competitions and the benefits for the community are addressed along the paper. Our analysis paves the way for future developments on the standardization of evaluations and for creating a widely-adopted benchmark strategy for researchers and companies in the field.We would like to thank Topcon Corporation for sponsoring the competition track with an award for the winning team. We are also grateful to Francesco Potorti, Sangjoon Park, Hideo Makino, Nobuo Kawaguchi, Takeshi Kurata and Jesus Urena for their invaluable help in organizing and promoting the IPIN competition and conference. Many thanks to Raul Montoliu, Emilio Sansano, Marina Granel and Luis Alisandra for collecting the databases in the UJITI building. Parts of this work were carried out with the financial support received from projects and grants: REPNIN network (TEC2015-71426-REDT), LORIS (TIN2012-38080-C04-04), TARSIUS (TIN2015-71564-C4-2-R (MINECO/FEDER)), SmartLoc (CSIC-PIE Ref. 201450E011), "Metodologias avanzadas para el diseno, desarrollo, evaluacion e integracion de algoritmos de localizacion en interiores" (TIN2015-70202-P), GEO-C (Project ID: 642332, H2020-MSCA-ITN-2014-Marie Sklodowska-Curie Action: Innovative Training Networks), and financial support from the Ministry of Science and Technology, Taiwan (106-3114-E-007-005 and 105-2221-E-155-013-MY3). The HFTS team has been supported in the frame of the German Federal Ministry of Education and Research programme "FHprofUnt2013" under contract 03FH035PB3 (Project SPIRIT). The UMinho team has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT-Fundacao para a Ciencia e Tecnologia within the Project Scope: UID/CEC/00319/2013. G.M. Mendoza-Silva gratefully acknowledges funding from grant PREDOC/2016/55 by Universitat Jaume I.info:eu-repo/semantics/publishedVersio

Next Generation Multi-System Multi-Frequency GNSS Receivers

Nowadays we have satellites available from GPS, GLONASS, Galileo and BeiDou systems. This will lead to an increased demand for solutions, which utilize multiple Global Navigation Satellite Systems (GNSS). Such solutions can have great market potential since they can be applied in numerous applications involving GNSS navigation, e.g. smartphones and car navigators. The aim of this thesis is to present the issues that arise in modern high sensitivity receivers, and to present research results of navigation algorithms suitable for the next generation multi-system multi-frequency GNSS receivers.With the availability of multiple satellites systems, the user benefits mostly from the improved visibility of the satellites. The increased availability of satellites naturally increases the computational requirements in the receiver. The main focus of the presented algorithms is on critical factors like provided accuracy versus low cost, low power consumption. In addition, the presented algorithms have been collected into a comprehensive navigation algorithm library where they have additional value for educational purposes.The presented navigation algorithms focus mainly in the GPS and Galileo systems, with the combination of L1/E1 & L5/E5a frequencies. A novel GPS + Galileo dual frequency receiver was developed by the team over the years. Where applicable, the thesis collects important facts from modern GLONASS and BeiDou systems.The first part of the thesis introduces all available open service signals from the GNSS systems, revealing how vast the scope of multi-system, multi-frequency receiver design is. The chapter continues with introduction to the basics of GNSS systems, and description of the problems that the receiver designer must overcome. The chapter further continues by describing a basic receiver architecture suitable for multi-system multi-frequency reception. The introductory part also has a short section is dedicated for underlining the importance of testing mechanisms for a novel receiver under development.The second part of the thesis concentrates on the baseband processing of the GNSS receiver. Topics cover acquisition and tracking, with multi-system multi-frequency implementation Abstract details kept in mind. The chapter also contains sections for issues that must be handled in high sensitivity receivers, e.g. cross-correlation and cycle slip detection. The second part of the thesis is concluded with a description how Assisted-GNSS capability would alter many of the design considerations.The third part of the thesis describes algorithms related to the data bit decoding issues. All the different satellite systems have their own low-level navigation data structure with additional layers of error detection / correction mechanisms. This part of the thesis provides the algorithms for successful decoding of the data.The final part of the thesis describes the basic navigation solution algorithms suitable for the mass-market receivers. In this part, the method of combining the measurements from the different satellite systems is discussed. Additionally, all the issues of processing multisystem signals are collected here, and in the end the Position, Velocity, and Time (PVT) solution is obtained

A Review of Environmental Context Detection for Navigation Based on Multiple Sensors

Current navigation systems use multi-sensor data to improve the localization accuracy, but often without certitude on the quality of those measurements in certain situations. The context detection will enable us to build an adaptive navigation system to improve the precision and the robustness of its localization solution by anticipating possible degradation in sensor signal quality (GNSS in urban canyons for instance or camera-based navigation in a non-textured environment). That is why context detection is considered the future of navigation systems. Thus, it is important firstly to define this concept of context for navigation and to find a way to extract it from available information. This paper overviews existing GNSS and on-board vision-based solutions of environmental context detection. This review shows that most of the state-of-the art research works focus on only one type of data. It confirms that the main perspective of this problem is to combine different indicators from multiple sensors

Test bench solutions for advanced GNSS receivers : implementation, automation, and application

Considerable study has been devoted to the implementation of GNSS receivers for diverse applications, and to finding solutions to some of the non-idealities associated with such receivers. However, not much research is devoted to innovations in their performance evaluation, even though this is an integral step in the overall implementation process. This research work attempts to address this issue through three different perspectives: by focusing on innovation in the testing procedures and test-bench implementation, its automation and its application to advanced multi-frequency, multi-constellation GPS and Galileo receivers. Majority of this research was conducted within the GREAT, GRAMMAR, and FUGAT projects funded by EU FP6/FP7 and TEKES respectively, during which the author was responsible for designing test-scenarios and performing validations of the implemented receiver solution. The first part of the research is devoted to the study and design of sources of test signals for an advanced GNSS receiver test-bench. An in-depth background literature study was conducted on software-based GNSS signal simulators to trace their evolution over the past two decades. Keeping their special features and limitations in view, recommendations have been made on the optimum architecture and essential features within such simulators for testing of advanced receivers. This resulted in the implementation of an experimental software-based simulator capable of producing GPS L1 and Galileo E1 signals at intermediate frequency. Another solution investigated was a GNSS Sampled Data Generator (SDG) based on wideband sampling. This included designing the entire radio front-end operating on the bandpass-sampling principle. The low noise amplifier designed as part of this SDG has been implemented on a printed circuit board. Phase noise (PN) from the radio front-end’s local frequency generator (LFG) is a source of error that has hitherto not been included in any GNSS signal simulator. Furthermore, the characterization of the baseband tracking loops in presence of this phase noise has not yet been included in the typical receiver test scenarios. The second part of this research attempts to create mathematical models representing the LFG’s phase noise contribution, first for a free running oscillator and later for a complete phase-locked loop (PLL). The effect of such phase noise was studied on the baseband correlation performance of GPS and Galileo receivers. The results helped to demonstrate a direct relation between the PN and the baseband tracking performance, thus helping to define guidelines for radio front-end PLL circuit design in order to maintain a minimum baseband tracking performance within the GNSS receiver. The final part of this research work focusses on describing the automated test-bench developed at Tampere University of Technology (TUT) for analyzing the overall performance of multi-frequency multi-constellation GNSS receivers. The proposed testbench includes a data capture tool to extract internal process information, and the overall controlling software, called automated performance evaluation tool, that is able to communicate between all modules for hands-free, one-button-click testing of GNSS receivers. Furthermore, these tools have been applied for the single frequency GPS L1 performance testing of the TUTGNSS receiver, with recommendations on how they can be adapted to testing of advanced multi-frequency, multi-constellation receivers