Satellite Communication and Positioning System

Descrizione

The topics of the course are:

• Atmospheric electromagnetic wave propagation: ionospheric propagation (physical description of the ionosphere and constitutive equations, total reflection, depolarization, attenuation, delay); tropospheric propagation (ray bending effects, scintillations and multipath, attenuation due to gases, clouds and effects due to rain, models for rain attenuation, depolarization due to rain and ice crystals).
• Noise in positioning and communication systems: thermal noise, shot noise, noise due to dissipative elements, antenna noise temperature, Low Noise Amplifier, overall noise of a receiver.
• Modulation techniques: analog modulation (amplitude modulation and associated transmitter block scheme, frequency modulation and associated transmitter block scheme); digital modulation (ASK, PSK, FSK, advanced modulation schemes, bit error rate, bit energy/noise spectral density ratio and its relationship with the bit error rate, Shannon theorem, some elements on information coding).
• Receivers: the heterodyne receiver; brief description of SDR and of AM and FM demodulators.
• Satellite systems: the link budget; different architectures and mission profiles for satellite positioning and communication systems.
• Satellite communication systems: satellite-based communication systems, broadcast (one-way) and telecommunication (two-way) architectures; data relay systems; GEO, MEO, LEO systems.
• Satellite-based localization and positioning: position estimation techniques based on time of arrival, positioning algorithms, the geometrical dilution of precision, uncertainty and error sources, error correction models, system architectures of modern GNSSs (e.g. GPS and Galileo), space segment (satellite architecture, orbits) and ground segment (monitoring stations, information for system correction/maintenance), augmentation systems, applications of GNSSs.