A GSTP Element 2 activity with France, has taken an existing product used to help signals from satellites reach underground and developed and improved it for navigation purposes.

Glass cells are typically used in Frequency Standard, both as reference cell, in the lamps for atomic pumping and as dissociator bulbs.When used in a lamp (RAFS or Mercury ion trap), the cell must be sufficiently resilient for avoiding limitations in the lifetime due to diffusion of material (i.e. Rubidium or Mercury) inside the bulb walls, given the combination of dissociation mechanisms and high temperatures.

The next generation of GNSS is expected to be more demanding in terms of RF power transmission in order to guarantee a proper availability and quality of the service, hence, enhanced interference immunity and indoor positioning could be achieved.The HPA currently under development for this application are targeting power levels in excess of 300 W.

The effects of propagation impairments, in particular multipath on GNSS receivers is well known, affecting availability, accuracy and continuity of service. Initial investigations on the possibility to reduce complexity of channel models for characterizing GNSS Rx in terms of tracking and/or PVT performance has been performed for example in the "GALILEO SIS TESTING" activity.Although promising results have been seen for the characterization of the statistics of the Rx, still limitations exist in this model reduction for characterising punctual fails (e.g. false lock due to high delay).

Current single-frequency Satellite Based Augmentation Systems (SBAS) and planned dual-frequency multi-constellation (DFMC) SBAS systems enable approach operations with vertical guidance with time to alarm (TTA) of 6 seconds, but do not support auto land operations with decision height (DH) much less than 200 feet, and time to alarm down to 1-2 seconds . These critical TTA requirements cannot be met by having all integrity monitors centralized at the Ground Segment. Therefore, there is a need to distribute the integrity monitors amongst different Ground, Space and User Segments.

GNSS and other positioning systems are expected to have a very important role in Smart Cities. In this context, the design of the high-level architecture of a testbed to support future applications of GNSS and other positioning systems in Smart Cities is of high interest. The design of this testbed shall consider as baseline the availability of a network of distributed smart sensors, which are remotely accessible and configurable from the cloud, and existing network infrastructures shall be considered.

The activity aims to develop techniques (e.g. high sensitivity algorithms, data wipe off for Galileo, optimal data plus pilot combinations etc.) in order to enhance the capability of mass market receivers taking into account their typical resources constraints (limited power, memory, open loop platform etc...). The activity shall investigate the application of these techniques for phase and code tracking down to the detailed design of the techniques for different type of usage and in different type of environment.

Open GNSS signal authentication is one of the main future challenges that the GNSS community will have to face in order to support safety critical applications. One of the major evolutions proposed for the Satellite Based Augmentation Systems (SBAS) systems is to provide authentication services to their users. This evolution is still under debate in international fora, therefore this activity proposes to investigate the issue starting from the consolidation of the spoofing scenarios and the potential anti-spoofing techniques that can be integrated in an airborne navigation system.

In an era of high resolution gravity field modelling the dominant error sources in spacecraft orbit determination are non-conservative spacecraft surface forces, such as: Solar Radiation Pressure, antenna thrust, Earth' albedo, thermal re-radiation, etc. The conventional approach to these problems is to use an empirical blind model which absorb all the forces but this approach introduces systematic errors and limit the prediction of the orbit. In the last years several wind-box model have appeared, developed based in GPS and Glonass official information, to overcome this limitation.