Papers by Gonzalo Seco Granados
Sensors, 2021
Accurate and reliable positioning solution is an important requirement for many applications, for... more Accurate and reliable positioning solution is an important requirement for many applications, for instance, emergency services and vehicular-related use cases. Positioning using cellular signals has emerged as a promising solution in Global Navigation Satellite System (GNSS) challenging environments, such as deep urban canyons. However, harsh working conditions of urban scenarios, such as with dense multipath and Non-Line of Sight (NLoS), remain as one of the key factors causing the detriment of the positioning estimation accuracy. This paper demonstrates that the use of joint Uplink Time Difference of Arrival (UTDoA) and Angle of Arrival (AoA) gives a significant improvement in the position accuracy thanks to the use of antenna arrays. The new advances of this technology enable more accurate user locations by exploiting angular domains of propagation channel in combination with time measurements. Moreover, it is shown that a better localization is achieved by combining the joined U...
arXiv (Cornell University), Jun 2, 2020
This white paper concludes by highlighting foundational research challenges, as well as implicati... more This white paper concludes by highlighting foundational research challenges, as well as implications and opportunities related to privacy, security, and trust. Addressing these challenges will undoubtedly require an inter-disciplinary and concerted effort from the research community.
La vulnerabilitat de les senyals GNSS vers interferències de radiofreqüència i spoofing s'ha conv... more La vulnerabilitat de les senyals GNSS vers interferències de radiofreqüència i spoofing s'ha convertit en una preocupació en aplicacions de radionavegació que requereixen un alt nivell de precisió i seguretat. Aquesta manca de precisió dels receptors GPS convencionals ha donat pas al desenvolupament de sistemes GPS multi-antena els quals integren diversos front-ends sincronitzats mitjançant un oscil•lador comú. L'objectiu principal d'aquest projecte es el desenvolupament d'una plataforma GPS de fàcil ús, calibrada i de baix cost utilitzant Software-Defined Radios (SDRs) i antenes GPS comercials. El hardware encarregat d'enregistrar les senyals captades per les diverses antenes GPS està format per tres Universal Software Peripherial Radios i un ordinador personal. La metodologia que es proposa per tal d'aconseguir una sincronització de fase entre els diferents frontends consisteix en l'ús de les diferències de fase observades d'una senyal de referència per tal de compensar el desfasament existent en les senyals captades per cada USRP. En comptes de fer servir un array d'antenes totalment calibrat i amb una geometria fixa, l'array que es proposa està format per tres antenes GPS comercials. Aquest enfocament permetrà a l'usuari de canviar la geometria de l'array de tal manera que es podrà adaptar a les necessitats de l'aplicació. Resumen: La vulnerabilidad de las señales GNSS frente a interferencias de radiofrecuencia y spoofing se ha convertido en una preocupación en aplicaciones de radionavegación que requieren un alto nivel de precisión y seguridad. Esta falta de precisión en los receptores GPS convencionales ha dado lugar al desarrollo de sistemas GPS multi-antena los cuales integran distintos front-ends sincronizados utilizando un oscilador común. El objetivo principal de este proyecto es desarrollar una plataforma GPS de fácil uso, calibrada y de bajo coste utilizando Software-Defined Radios (SDRs) y antenas GPS comerciales. El hardware encargado de grabar las señales captadas por las distintas antenas GPS está formado por tres Universal Software Peripheral Radios y un ordenador personal. El método propuesto para conseguir una sincronización de fase entre los distintos front-ends consiste en el uso de las diferencias de fase observadas de una señal de referencia para compensar el desfase existente en las señales captadas por cada USRP. En vez de utilizar un array de antenas totalmente calibrado y con una geometría fija, el array que se propone está formado por tres antenas GPS comerciales. Este enfoque permitirá al usuario cambiar la geometría del array de modo que se adapte a las necesidades de la aplicación.
Proceedings of the 31st International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2018), 2018
Integrity in the domain of Global Navigation Satellite Systems (GNSS) has been understood as the ... more Integrity in the domain of Global Navigation Satellite Systems (GNSS) has been understood as the ability of detecting and alerting of incorrect user positions, providing therefore a certain level of reliability or trust in the estimated user location. This concept of integrity was imported from the "safety-critical" aviation services, thus requiring an extremely high level of reliability, and it has been one of the drivers of satellite navigation systems in the past decades. As the use of GNSS has also expanded to mass market users, terrestrial user communities have also shown interest in applications requiring reliable positions. These terrestrial "liability-critical" applications (i.e. initially referred to applications that require a certain level of trust for economical or legal reasons, and later extended to terrestrial applications that require a level of trust for whatever purpose) require a high level of reliability, but somehow lower than in aviation. Ho...
The use of GNSS has expanded to mass market users and most of them are located in populated areas... more The use of GNSS has expanded to mass market users and most of them are located in populated areas and roads where local environmental characteristics, which include buildings, trees, moving objects, etc., increase the multipath and the Non-Line-of-Sight (NLoS) effects, thus dominating the GNSS measurement errors. Also threats like radio frequency (RF) interference and spoofing can affect the positioning service. These local characteristics, which cannot be corrected by the ground or satellite segments, degrade the signals leading to potentially high positioning errors and therefore may also hinder the provision of a full integrity positioning service. The purpose of the current study is to assess the possibilities that a mass-market level multi-antenna device could offer in order to improve integrity by identifying faulty measurements (i.e. high error measurements). Using the real data collected with a GPSG this is because antenna phase differences contain information related to the...
Providing integrity to precise positioning navigation techniques utilizing carrier-phase measurem... more Providing integrity to precise positioning navigation techniques utilizing carrier-phase measurements, like Precise Point Positioning (PPP) and Real-Time Kinematic (RTK), is still a challenge. Whereas these methods can provide centimetre-level positioning accuracy, their use has been limited mainly for static and kinematic positioning solutions, with less employment for general navigation purposes. Both techniques are dependent on external information which has to be considered in the integrity monitoring process.
Proceedings of the 29th International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2016), Nov 8, 2016
BIOGRAPHY Enrique Domínguez received a M.Sc. degree in Telecommunications Engineering in 2000 and... more BIOGRAPHY Enrique Domínguez received a M.Sc. degree in Telecommunications Engineering in 2000 and a Master in Space Technologies in 2009, both from the Polytechnic University of Madrid. He joined GMV in 2000 working first in the development of EGNOS and Galileo and since 2009 in GNSS software receivers, multi-sensor fusion algorithms and integrity algorithms.
Digital Signal Processing, 2018
This paper focuses on inhomogeneous quadratic tests, which involve the sum of a dependent non-cen... more This paper focuses on inhomogeneous quadratic tests, which involve the sum of a dependent non-central chisquare with a Gaussian random variable. Unfortunately, no closed-form expression is available for the statistical distribution of the resulting random variable, thus hindering the analytical characterization of these tests in terms of probability of detection and probability of false alarm. In order to circumvent this limitation, two closed-form approximations are proposed in this work based on results from Edgeworth series expansions and Extreme Value Theory (EVT). The use of these approximations is shown through a specific case of study in the context of integrity transient detection for Global Navigation Satellite Systems (GNSS). Numerical results are provided to assess the goodness of the proposed approximations, and to highlight their interest in real life applications.
GPS Solutions, 2017
The geometric dilution of precision (GDOP) is related to the satellite geometry. Thus far, resear... more The geometric dilution of precision (GDOP) is related to the satellite geometry. Thus far, research has focused on minimizing the GDOP by selecting a set of satellites that maximizes the volume spanned by the userto-satellite unit vectors. However, this relation has been only analyzed when four satellites are used for computing the three-dimensional position, for which the relation is nearly direct. The analysis applicable to any number of satellites is presented here. Results show that the relation between GDOP and volume spanned by the user-to-satellite unit vectors does not ensure that the optimal GDOP value is achieved by means of the volume maximization. Satellite distribution should also be considered in such a way that the selection of geometries that are closer to a regular polytope is favored.
25th AIAA International Communications Satellite Systems Conference (organized by APSCC), 2007
Resource Management in Satellite Networks, 2007
... Contributors: Nedo Celandroni2, Franco Davoli3, Erina Ferro2, Alberto Gotta2, Stylianos Karap... more ... Contributors: Nedo Celandroni2, Franco Davoli3, Erina Ferro2, Alberto Gotta2, Stylianos Karapantazis4, Giada Mennuti1, Antoni Morell5, Tommaso Pecorella1, Gonzalo Seco Granados5, Petia ... A self-similar traffic with Hurst parameter H = 0.8 has been used to feed each RCST. ...
Signals and Communication Technology, 2014
This chapter provides an introduction to the Galileo program and architecture. It starts by prese... more This chapter provides an introduction to the Galileo program and architecture. It starts by presenting the program context, rationale and history, including the early definition phases and test beds and the GIOVE experimental satellites. It then presents an overview of the Galileo services. Later, an architectural overview is provided, including the Galileo segments: the Space Segment, the Ground Mission Segment, and the Ground Control Segment. The chapter also provides a description of Galileo's contribution to the Search And Rescue services through COSPAS/SARSAT, and finalizes with an overview of the user segment and highlighting interoperability and compatibility issues with other GNSS.
IEEE Journal on Selected Areas in Communications, 2009
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Papers by Gonzalo Seco Granados