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• Atmospheric probing using GNSS
This study carried out under the CNES (Centre
national d’études spatiales) in collaboration with the
LaMP (Laboratoire de Métrologie Physique) of
Clermont-Ferrand University aims to validate the
precision of measurements of pseudo-distances
possible with Galileo in order to allow performance
simulation of the system for atmospheric probing.
In this study, we evaluated the effect of 2 and 3 order
ionospheric terms using archived data. Reception
from the Giove A satellite was set up in 2008, with
the help of a Septentrio receiver. This work, which
was completed at the end of 2008 demonstrated a
growing precision provided by Giove for measuring
pseudo-distances. This increased precision,
resulting from the transmission of highperformance
pseudo-random codes, allows us to
envisage more ambitious corrections of ionospheric
effects
• Prediction of ionospheric scintillation (PRIS)
ARTES-5
This is an ESA contract in partnership with IEEA, in
which IETR 3 , DLR 4 (Germany) and GMV 5 (Spain)
participate. Télécom Bretagne is responsible for a
GPS scintillation monitor in Vietnam. The study of
ionospheric scintillations, which are particularly
intense in equatorial regions, constitutes a major
challenge for the availability and integrity of the
future GNSS. The acquisition of scintillations
measurements from Vietnam took place during the
period 2006-2008. Initial observations seemed to
show behavioural differences between the Southeast
Asian ionosphere and that of South America.
ESA activity ended in August 2008 with a final
written report. This study allowed to refine the
techniques of data-processing of scintillations and
to compare scintillations recorded at various points
of the globe, located in equatorial and polar zones,
with predictive models. This comparison showed
that the models studied can be considered
satisfactory from a statistical point of view but do not
allow a viable short-term forecast of a particular
event.
3) IETR : Institut d’électronique et de télécommunication de Rennes
4) DLR : Deutsches Zentrum für Luft
5) GMV :
• GPS - GALILEO
Part of the work of the TIME team of UMR CNRS
TAMCIC concentrates on characterising GPS type
signals that are quite sensitive to interferences from
other radar systems and are consequently sensitive
to various and different interferences. The aim of
this study was to analyse from a theoretical point of
view (study paper) and a practical (experimentbased)
point of view the performance of a bi-static
SAR system available satellite transmission
opportunities (GPS). This work is linked to a study
carried out under an ONERA contract. Besides, one
contract has been validated in a Europôle Mer
project. This project (MPOS : Marine Opportunity
Passive Systems) aimed to characterise and
measure the GPS/GALILEO signal which was
returned from the sea surface – comparing it with a
direct signal – extracting information about sea
surface agitation and currents.
At the same time, the GalileOcean project, labelled
Pôle Mer, was redefined in order to be able to use
the data and the results obtained by the acquisation
platform developed in the CapSys project.
• HF SATIS propagation software
A study aimed at improving the SATIS ionospheric
propagation forecast software was carried out in
2008 under a THALES Communications contract.
This study aimed at allowing SATIS to be used as
embedded software in MELCHIOR, the real-time HF
communications management system.
Studies and experiments concerning the
characterisation and modelling radio-electric
propagation channels principally concerned:
• Advanced study of the effect of antennae on radio
channels
The innovative RNRT project RADIC-SF allowed
developing a transverse approach between wave,
signal domains, and protocols for the study of
configurations of wireless networks of diverse
cooperation. For this, the quality in the transmission
channel modelling is a challenge of prime
importance for traffic simulators from which
efficient network strategies will be validated. At both
ends of the channel, antennae have a key role, in the
context of MIMO architecture. From a fundamentally
deterministic approach, and in continuity with
previously developed CAPSYS study (particularly
EPAR-3D), work concentrated on a good
understanding of the propagation channels
associated with these new networks. During the
first phase, pertinent statistical parameters for
modelling VHF, UHF and SHF band channels of
radio-electric communication were identified. This
was done on the basis of rigorous modelling
founded on an asymptotic approach to wave
propagation (the uniform theory of diffraction and
automatic ray calculation). The acquisition in 2008
of the WinProp software very effectively reinforced