The main aim of this research is to generate and upgrade prediction models
of radio propagation impairments, necessary to design satellite systems at
centimetric and millimetric wavelengths with large capacity. To obtain this
goal, an extensive use was made of the experimental equipments at disposal:
an S band meteorological radar, radiometers operating in the 13-50 GHz
frequency bands, and an ASI receiving station for different satellites. Two
main research areas have been considered:
1) The evolution of satellite communication techniques has brought the use
of higher frequencies (V and W bands), wider interconnections among fixed
and mobile terminals, very large LEO and MEO satellite constellations. This
new scenario requires to know the radio propagation characteristics of the
satellite channels in any climatic condition, the spatial distribution of
rain attenuation in large areas, its dynamic behaviour, the influence of
factors such as orography, buildings, vegetation.
2) The meteorological radar located at Spino d'Adda can measure the
reflectivity of targets (rain rate of rain cells) and doppler data from
each range (radar maps). As both measurements do not yield the quantities
of interest (rain rate) directly, then proper data calibration is necessary
by means of external sources.
In the past, different radar experimental campaigns were carried out,
mainly by collecting reflectivity maps, then followed by a radar
calibration on a statistical basis.
Activities:
- Propagation experiment with a satellite beacon at 20 GHz and with
radiometers at 13, 20, 30, 50 GHz at the station located at Spino d'Adda.
- Processing of the experimental data of attenuation, depolarization and
scintillation at the above frequencies.
- Development and refinement of propagation models and proposals of radio
regulations.
- Development of software packages to simulate complex radio systems and to
evaluate the radio channel characteristics.
- Radar acquisition and processing of rain rate maps for telecommunication
applications. The radar facility continuously operates to produce radar
maps during rainfall necessary for weather forecast and for environment
protection applications.
- Partecipation in the ASI small mission program (DAVID). The program
foresees to use a small LEO satellite which will transmits to many small
ground terminals with the scope to test advanced fade countermeasure
techniques which will manage a common reserve available to all the small
ground terminals.
- Study of models for the radio propagation channel in urban and
extra-urban environment in fixed and mobile systems.
Focus