Javier Ventura-Traveset

European Space Agency | ESA

This publication introduces the proposed ESA MARs COmmunication and Navigation Infrastructure (MARCONI) which has been proposed to deliver communication and navigation services starting in the first half of the next decade. This infrastructure provides a GNSS-like (Global Navigation Satellite System) ranging capability by broadcasting the MAFS (Mar...

The development of dedicated Lunar Communication and Navigation System (LCNS) infrastructure, envisioned within the Moonlight initiative of the European Space Agency (ESA), will lay the foundations for autonomous lunar navigation of surface rovers, and orbiting and landing spacecrafts. The absence of lunar ionosphere makes the deployment of a refer...

Improving and homogenizing time and space reference systems on Earth and, more specifically, realizing the Terrestrial Reference Frame (TRF) with an accuracy of 1 mm and a long-term stability of 0.1 mm/year are relevant for many scientific and societal endeavors. The knowledge of the TRF is fundamental for Earth and navigation sciences. For instanc...

Improving and homogenizing time and space reference systems on Earth and, more directly, realizing the Terrestrial Reference Frame (TRF) with an accuracy of 1mm and a long-term stability of 0.1mm/year are relevant for many scientific and societal endeavors. The knowledge of the TRF is fundamental for Earth and navigation sciences. For instance, qua...

In the last years, the Moon has been put again on the top of the space exploration interests. Both space ag en cies and private companies are being involved in mission programs that aim at establishing a stable p resen ce o n the Moon surface in this decade. In all these initiatives, navigation and communication play a major role. Within this conte...

With the renewed interest for lunar surface exploration, the European Space Agency envisions to stimulate the creation of lunar communications and navigation services (LCNS) to enable, among others, autonomous navigation capabilities for lunar rovers. As the number of satellites foreseen in such a service is much smaller compared to Earth based glo...

The interest in Moon exploration has grown substantially in the last few years, appointing the Moon as the first step toward deep space exploration. However, the current state-of-the-art approach for lunar landing does not always reach the required performance levels. This contribution presents a potential implementation of a dedicated lunar commun...

The momentum taken by the space sector in the exploration of our Moon pushes private and governmental actors to intensify their efforts for launching missions to our natural satellite. In this context, novel infrastructures and techniques are being studied and experimented to reach an increased autonomy of the positioning and navigation services in...

The interest in Moon exploration has substantially grown in the latest years, positioning the Moon as an attractive testbed to develop the required technologies and capabilities for human Deep Space exploration. In past decades, lunar missions have almost entirely relied on Direct-to-Earth (DTE) communications, whilst using ranging radiometric meas...

The internal roadmap for deep space exploration proposed by the International Space Exploration Coordination Group (ISECG) clearly identifies the Moon as the first step towards a larger solar system exploration. In this context, the use of Earth Global Navigation Satellite System (GNSS) signals at Moon altitude has been extensively studied in the p...

A new lunar economy of moon exploration by space agencies, private companies and public-private partnerships has emerged, with initiatives involving robots, habitat and transportation. All the proposed missions share similar navigation and communication needs that could be potentially and efficiently satisfied through a dedicated lunar system. In...

Today, deep space missions are navigated and tracked with Deep Space Tracking Stations. However, the navigation operations are relatively expensive and the accuracy is within kilometre range, which needs to be improved for human space exploration. This paper will present initial results of a system study about a Lunar Navigation Satellite System. T...

As a significant number of people and robotics venture into space, infrastructures providing critical services such as GNSS must be considered on a large extra-terrestrial scale to support these explorations and settlements. The next global strategic priority in space, the moon, has dozens of missions planned for this decade, with private as well...

In the context of Deep Space Exploration as planned by the International Space Exploration Coordination Group (ISECG), the Moon represents a significant step to feed forward what could be done on Mars. Navigation is a key-technology to enable the cis-lunar and lunar volume discovery. The use of Earth Global Navigation Satellite System (GNSS) signal...

“We are not going back to the Moon, we are going forward to the Moon” said Jan Woerner, Director General of the European Space Agency (ESA) in 2018, as reported by Space News. Indeed, in the context of Deep Space Exploration as planned by the International Space Exploration Coordination Group (ISECG), the Moon represents a significant step to feed...

On August 22, 2014, the satellites GSAT-0201 and GSAT-0202 of the European GNSS Galileo were unintentionally launched into eccentric orbits. Unexpectedly, this has become a fortunate scientific opportunity since the onboard hydrogen masers allow for a sensitive test of the redshift predicted by the theory of general relativity. In the present Lette...

We report on a new test of the gravitational redshift and thus of local position invariance, an integral part of the Einstein equivalence principle, which is the foundation of general relativity and all metric theories of gravitation. We use data spanning 1008 days from two satellites of Galileo, Europe's global satellite navigation system (GNSS),...

Recognizing the strategic importance of satellite navigation and its applications, a European approach was developed in the 90s. The European strategy on satellite navigation was then based on two major steps, what was known as GNSS-1 and GNSS-2, linked respectively to the European Geostationary Navigation Overlay Service (EGNOS) and Galileo infras...

Satellite navigation is progressing at such a rapid pace that it is difficult to keep track of the latest evolutions, satellite launches, technologies or even systems and signals. With Navipedia, the European Space Agency has introduced a common online entry point for GNSS know-how. As with all media-wiki products, any registered user can comment,...

ESA Education Office currently offers university students, through four different programmes, the opportunity to perform a scientific or technology experiment under either microgravity or hypergravity conditions. “Fly Your Thesis!” enables students to participate in a series of three flights of 30 parabolas each, with each parabola providing about...

“Fly Your Thesis!—An Astronaut Experience” is an educational programme launched by the ESA Education Office that aims to offer to European students the unique opportunity to design, build, and eventually fly, a scientific experiment as part of their Master or Ph.D. thesis. Selected teams accompany their experiments onboard the Zero-G aircraft for a...

Satellite Navigation has become a keystone for the development of Europe and its citizens. It is then essential to provide adequate educational programmes so to ensure a prepared workforce for the GNSS sector in Europe. In this context, ESA has launched a complete Satellite Navigation Educational program, called EDUNAV, aiming at providing upto-dat...

Satellite Navigation has become a keystone for the development of Europe and its citizens. It is then essential to provide adequate educational programmes so to ensure a prepared workforce for the GNSS sector in Europe. In this context, ESA has launched a complete Satellite Navigation Educational program, called EDUNAV, aiming at providing up-to-da...

This paper will introduce three new European Space Agency (ESA) Education Office hands-on activities. These educational programmes give respectively access to aircraft parabolic flight, drop tower and centrifuge campaigns to students from ESA Member and Cooperating States. They offer university students the unique opportunity to design, build, and...

ESA provides numerous opportunities for university students from ESA Member and Cooperating States to gain practical hands-on engineering experience on real space projects. These opportunities cover a broad spectrum of flight project activities ranging from student experiment payloads on microgravity platforms, atmospheric balloons, and sub-orbital...

"Fly Your Thesis! - An Astronaut Experience" is a new programme launched by the ESA Education Office and aims to offering European students the unique opportunity to design, build, and eventually fly, a scientific experiment as part of their Master or PhD thesis. Selected teams accompany their experiments onboard the Zero-G aircraft for a series of...

Fly Your Thesis! – An Astronaut Experience " is a new programme launched by ESA's Education Office which consists in offering a unique opportunity for European students to design, build, and eventually fly, a scientific experiment to be performed in microgravity, as part of their last year of University, Master or PhD thesis. The students will part...

European Space Astronomy Centre (ESAC) is the home of ESA's space telescope and planetary missions. The various activities that are carried out at ESAC includes the contributions to the ESA tracking stations network (ESTRACK) with a special link to the nearby Cebreros 35m ESA deep-space ground station, the new SMOS Earth observation satellite groun...

A 'centre of excellence' for space science and ESA's hub for science operations, the European Space Astronomy Centre (ESAC) is the home of ESA's space telescope and planetary missions.

The European Space Agency (ESA) established the Education Office , to encourage young people to study science and technology and prepare skilled space research professionals for potential space research programs. The Education Office supports student activities, including the design, development, integration, testing, launching, and operating small...

A new diagram for SBAS integrity validation is presented in this paper. The proposed concept is a modification of the well known Stanford plot, where a 2D histogram shows the relationship of position errors against protection levels for a set of measurements using an all in view satellite selection. The method consists on a new representation (know...

The ICAO-validated SBAS integrity concept has been summarised and some examples associated with ESA's current design of EGNOS have tried to illustrate how it may be implemented in practice, trying to highlight following items: integrity allocation between the different potential error contributors; difference between the integrity definitions exist...

EGNOS is the main European contribution to GNSS-1 to serve the needs of maritime, land transport, time and aeronautical applications in the European and neighbouring regions. For aviation, EGNOS AOC will be used in the ECAC Region as a primary means of navigation for all phases of flight down to APV. EGNOS is the first-generation European GNSS Syst...

In this article, a new concept for SBAS integrity validation is presented. It is a modification of the well-known Stanford Diagram [2], where a 2D histogram shows the relationship of position errors against protection levels for a set of measurements using an all in view satellite selection. The new method consists of two diagrams: the Worst-Safety...

Satellite navigation has already found a large number of applications in a wide variety of fields. Recognising the strategic importance of those applications, a European approach was developed in the early 1990s. The European strategy for satellite navigation is based on two fundamental steps, namely GNSS-1 and GNSS-2. The first-generation Global...

Satellite-based Augmentation Systems (SBAS) such as the European Geostationary Navigation Overlay Service (EGNOS) augment GPS and GLONASS, providing and guaranteeing the availability of navigation signals for aeronautical, maritime and land mobile applications. The ionospheric information provided by the augmentation system is a key issue for accur...

This summer, after more than 8 years of intensive work by ESA and European Industry, the European Geostationary Overlay Service (EGNOS) achieved two major programme milestones, with the successful completion of the formal technical-qualification process (Operational Readiness Review) and the start of initial operations. The measured performance of...

Over the last 20 years, major developments have taken place in parallel in the key technology areas of wireless communications and satellite navigation. Both are gradually becoming indispensable tools in the professional and consumer worlds. Nowadays, major synergies are developing in terms of wireless mobile terminals with a navigation capability,...

Satellite-based augmentation systems (SBAS), like GPS, suffer from visibility limitations in urban settings. A prototype receiver combines EGNOS correction messages received through a wireless Internet connection with pseudorange measurements from its internal GPS receiver, delivering a significant improvement in positioning accuracy and availabili...

The European Tripartite Group (ETG)1, (ESA - EC - EUROCONTROL) is implementing, via the EGNOS project (1), the European contribution to the Global Navigation Satellite System (GNSS-1) which will provide and guarantee navigation signals for aeronautical, maritime and land mobile Trans- European network applications. On behalf of this Tripartite grou...

Likewise other Satellite Based Augmentation Systems (SBAS), EGNOS- the European SBAS - will broadcast augmentation signals for GPS through Geostationary Earth Orbit (GEO) satellites. GEO broadcasting is proved to be an efficient strategy for avionic applications and other modes of transport. For some applications, though, it may be of interest to c...

The EGNOS service will provide better positioning availability and accuracy than that from the standalone GPS solutions. However, in order to access the EGNOS service, the end user needs to access the corresponding GEO satellites that broadcast the augmentation information for the region. This is not a problem normally for aviation and maritime app...

The European Tripartite Group* - consisting of ESA, the European Commission and Eurocontrol - is implementing, via the EGNOS project, the European contribution to the Global Navigation Satellite System (GNSS-1), which will provide and guarantee the availability of navigation signals for aeronautical, maritime and land mobile trans-European network...

Europe, US/Canada and Japan are currently developing their own regional Satellite Based Augmentation Systems (SBAS). Although all SBAS are regional systems, the necessity to establish adequate ways for co-operation and co-ordination among the different SBAS providers is recognised, in order to provide SBAS interoperability. Interoperability implies...

The European Geostationary Navigation Overlay System (EGNOS) is being developed in Europe to provide GPS and GLONASS satellite-based augmentation services to aviation, maritime and land users. EGNOS is a major element of the European Satellite Navigation Programme which is jointly being implemented by the European Union, the European Space Agency (...

This paper is a tutorial on the calculation of error probabilities for fading channels. The method we advocate is centered on the evaluation of the Laplace transform Φδ(s) of the probability density function of the difference A between the metrics of two competing signal sequences. In some cases, knowledge of the function Φδ (s) allows one to deter...

In this paper, the performance of coding and diversity in narrowband wireless cellular systems affected by fading, shadowing and co-channel interference is analyzed. We consider low-order diversity, that can be practically realized for both coherent and differential phase shift keying. We assume that the shadowing random processes affecting all tra...