The Grande Albergo Ausonia & Hungaria (Venice Lido, Italy) has an Art Nouveau polychrome ceramic coating on its façade, which was restored in 2007. Soon after the conservation treatment, many tiles of the façade decoration showed coloured alterations putatively attributed to the presence of microbial communities. To confirm the presence of the biological deposit and the stratigraphy of the Hungaria tiles, stereomicroscope, optical and environmental scanning electron microscope observations were made. The characterisation of the microbial community was performed using a PCR-DGGE approach. This study reported the first use of a culture-independent approach to identify the total community present in biodeteriorated artistic tiles. The case study examined here reveals that the coloured alterations on the tiles were mainly due to the presence of cryptoendolithic cyanobacteria. In addition, we proved that the microflora present on the tiles was generally greatly influenced by the environment of the Hungaria hotel. We found several microorganisms related to the alkaline environment, which is in the range of the tile pH, and related to the aquatic environment, the presence of the acrylic resin Paraloid B72® used during the 2007 treatment and the pollutants of the Venice lagoon.

2014. During Master studies he specialized in aerospace technology and navigation. After working in the field of sensor fusion and navigation aiding at Fraunhofer IOSB he joined German Aerospace Center (DLR) in May 2015 and is involved in the research on GBAS now. Dr. Ilaria Martini received the Master's degree in telecommunication engineering and the Ph.D.

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The High Accuracy Service (HAS) is an upcoming addition to the Galileo service portfolio that offers free correction data for precise point positioning in real-time. Beyond terrestrial and aeronautical applications, precise orbit determination (POD) of satellites in low Earth orbit (LEO) has been proposed as a potential use case for HAS corrections in view of their global availability. Based on HAS data collected during a test campaign in September 2021, the benefit of HAS corrections is assessed for real-time, onboard navigation as well as near real-time POD on the ground using GNSS observations of the Sentinel-6A LEO satellite. Compared to real-time POD using only broadcast ephemerides, performance improvements of about 40%, 10%, and 5% in terms of 3D position error can already be achieved for GPS-only, GPS + Galileo, and Galileo-only navigation. While Galileo processing benefits only moderately from the HAS correction data during the early tests in view of an already excellent Open Service performance, their use is highly advantageous for GPS processing and enables dual-constellation navigation with balanced contributions of both GNSSs for improved robustness. For near real-time offline POD, HAS corrections offer reduced latency or accuracy compared to established ultra-rapid GNSS orbit and clock products as well as independence from external sources.

Within the next future, the advent of Galileo, GPS modernization and of the GNSS augmentation systems, will lead to a rapid development of GNSS receiver technologies. It is expected that the improved accuracy performance will extend the use of satellite positioning and navigation to applications where present systems do not fulfill user integrity requirements and do not allow the receiver certification.In this scenario a central role is played by the integrity receiver capability. In fact a large part of users is carrying out applications in which an error in might represent an excessive risk, in particular when human lives are involved. For these applications, the system capability of protecting the user against system failure is of primary importance. The main example is given by aeronautical applications where at present the fulfillment of integrity requirements during approaches of type CAT I (and higher) has still to be reached.In this context, it is essential for the user to take advantage of Receiver Autonomous Integrity Monitoring (RAIM) techniques. In fact, although regional integrity is provided by space-based augmentation systems (SBAS) like EGNOS, WAAS and MSAS and global integrity will be transmitted by the European Galileo satellite navigation system in the near future, RAIM is the only technique able to monitor receiver local errors. Since it is located at the end of the integrity processing chain, its role is essential in the integrity determination process.It is also highlighted that present RAIM techniques have limitations, which in particular jeopardize the possibility to certificate satellite navigation receiver as sole or stand alone positioning platform in aeronautical applications. The main limitation is represented by the fact that all present RAIM techniques protect users only against one single failure affecting a particular satellite range measurement. Multiple failure events are usually assumed to have a very low probability of occurrence. But since in safety of life applications the continuity and availability requirements in terms of probability of missed detection are very strict, the multiple failure events need more attention and cannot be disregarded anymore by RAIM techniques.This paper presents an investigation on present RAIM technique and their performance with respect to multiple failures. Furthermore it presents a technique able to overcome the present integrity monitoring limitations and to protect the user receiver in case of multiple failures.

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