Nebula Public Library

By conventional data it is meant data coming from well-known sources such as permanent GNSS receivers (e.g. receivers from IGS or EUREF networks) while non-conventional data is considered to be GNSS data from research vessels or mass-market GNSS receivers (such as smartphones or other single-frequency GNSS chipsets).

Although the first laser communication systems were demonstrated in space in the 1990s, it is only recently that the technology, reliability and economics of space based optical systems have combined with the need for more bandwidth to push them into operation. Developments supported by space agencies pave the way for a commercial use of optical technologies, which are planned to revolutionize communication network architectures by introducing a hybrid terrestrial/space options.

The development of High Altitude Pseudo-Satellites (HAPS) has reached an outstanding level of maturity, with several flight demonstrations that augur soon to have operational capabilities. ESA, aware of the synergies among satellite and HAPS services, setup the HAPPIEST study to analyse the impact of the irruption of aerostatic HAPS into the telecommunications market, currently covered by space and terrestrial networks. Furthermore, some complementary payloads can serve interesting applications such as Earth observation and navigation services. The objective of HAPPIEST is

The purpose of this study is the definition of 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.