GNSS sensor stations, part of large GNSS infrastructure, provide the key inputs for the core processing facilities to compute orbit, clocks , ionosphere products and even integrity corrections.

The mixed signal (SiGe BiCMOS) technologies have been under interest in the specific area of signal generation due to good achievable signal quality. Meanwhile, the technology has been improved to reach higher operating frequencies and lower noise figures, too. The SiGe is very well suited for digital receiver implementation at L-band.The advantage of SiGe over GaAs in space use is foreseen in the high degree of integration due to the feasibility of mixing analogue and digital functions on a single chip. This means that the complete microwave system (e.g.

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The purpose of this study was to define the a communication subsystem architecture (including both ground and space segments, as well as operational methods) that allows robust RF TT&C links during superior solar conjunction phases. The defined architecture shall ensure robust and reliable links in scintillation regimes (i.e. at low SEP angles) where TT&C links are nowadays degraded, leading to occasional link interruptions. Similarly, the defined architecture shall ensure that at even higher scintillation regimes (i.e.

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Provision of integrity in harsh terrestrial environment is very difficult due to the increasing rate of failure induced by the local effects. Analysis of these events shall be performed together with the possible countermeasure and detection mechanism in order to minimise the integrity impact maximising service availability and continuity. Ground Integrity Channel as EGNOS and GALILEO will only cover the system events so usage of local solutions is mandatory to cope with the local threats.

Given that a navigation signal is weak when received by a GNSS receiver on earth it can be easily interfered by other signals. Field campaigns, performed up to now, at numerous locations, have shown that the level of interference in Galileo E5 and E6 could be, quite often, significantly higher than the typical level of interference in Galileo E1. In the frame of the ESA GSP activity Interference Information Systems (IIS) several concepts for interference mitigation were proposed and preliminary assessed from a theoretical and conceptual perspective; amongst them the following:1.

Carrier phase measurements are more precise than pseudorange measurements and are used for high precision services. The quality of the carrier phase measurements influences directly the Galileo/EGNOS Ground-Segment navigation and integrity algorithms output quality, as well as the GPS/Galileo professional and mass market user positioning accuracy. Unfortunately, phase tracking can be severely stressed under ionospheric scintillation (under severe scintillation, phase may change too fast for being tracked by the receiver).

The Asteroid Impact Mission (AIM) is a candidate ESA mission to the binary Near-Earth Asteroid (65803) Didymos. While its main objective is to demonstrate new technologies for future deep-space missions, AIM will also characterise for the first time a binary asteroid system, providing an understanding of its formation and of the origin of the Solar System.