In the manuscript of my thesis, I describe my research work concerning signal and image processing, and instrumentation for astronomy. I also present the projects I intend to develop in the next few years. The thematic areas I dealt with were numerous and diverse, and the applications concerned, among others, visual and spectroscopic double stars, tidal effects in Am-type stars, shell galaxies, atmospheric turbulence and wind profiles with the SCIDAR technique.

Among the main astrophysical results to which I contributed, are the validation of merging models to explain the origin of shells around elliptical galaxies, the evidence of the presence of dark matter in those galaxies, the detailed study of many spectroscopic binaries with the constitution of representative samples, including long period orbit systems containing FGKM Am or composite spectrum stars. In particular, a thorough study of a sample of a hundred Am-type stars highlighted the influence of tidal effects, which contributed to circularizing the orbits and to synchronizing the spin and orbital motion in many systems. The fractional critical radii for circularisation and synchronisation that we have determined for our sample were found to be compatible with Zahn's theoretical models. We have also compared the estimated ages of our systems with the theoretical circularisation and synchronisation characteristic times, also predicted by Zahn. We found a fair agreement for the synchronism, but for circularisation, the tidal effects we have observed are more important than what was expected by the theory, forAm-type stars with a radiative envelope.

As regards the visual binary stars, in collaboration with a group of European researchers, we have obtained a few thousand measurements with the PISCO and PISCO2 instruments, by using the speckle interferometry technique. Those accurate measurements have been calibrated in an absolute way with a diffraction grating. Their spatial resolution often reached the diffraction limit of the telescope. They have already led to the revision of a few hundred orbits. As their orbital periods are very long, and generally exceed a few hundred years, the observation of the visual double stars is a substantial program, which requires reliability and regularity over a very long period of time. This program needs an international collaboration that has been already active since several generations. As soon as they have been published, our measures were incorporated into the double star data base of the US. Navy in Washington DC, which is open to the whole scientific community.

With regard to instrumentation, my activities mainly concerned the designing, construction and operation of the PISCO and PISCO2 focal instruments. A substantial part was devoted to real-time software developments for the remote control of the instruments and the detectors, and the subsequent data processing. The main selected criteria were ''performance and reliability'', both for hardware and software developments. Indeed those instruments and programs have been used during nearly every clear night, for many years (more than 20 years for PISCO, and already five years for PISCO2).

The processing of PISCO data also lead me to developing programs for atmospheric turbulence profile inversion from SCIDAR observations, that can be operated in real-time and in a non-supervised mode. Those programs allow the restoration of turbulence profiles (C_N^2 parameter, seeing, coherence radius and coherence time) and of the wind parameters (velocity and direction) in the turbulent layers. When the observations are obtained in ''generalized SCIDAR'' mode, we can determine those parameters in all the turbulent layers that have been crossed by the incoming light, from the inside of the dome to altitudes up to 20--23~km. I have also written specialized software for computing orbits from radial velocities for multiple stellar systems made of two or three components. The main difficulty of this problem rested in the irregular sampling of the measurements. Finally, over the last few years, I have been working on the problems encountered for the phase self-calibration for aperture synthesis in astronomy, and for the calibration of GNSS (Global Navigation Satellite System) networks in geodesy, to which my principal collaborator, A. Lannes (L2S, Paris), has proposed an elegant and original solution.For the coming years, I would like to work in collaboration with colleagues, but also if possible with some students (graduate trainees or PhD students) on the following projects:

-- ''Instrumentation'' projects concerning (i) transfer of PISCO to the new EST 1 m telescope of OCA (Obs. Côte d'Azur), with the automation of the data acquisition and processing. (ii) automation of PISCO2 on the L76 refractor of OCA, and (iii) software development for the ''Shack-Hartmann'' mode of PISCO.

-- "Signal processing" projects about (i) the implementation of the calibration methods proposedby A. Lannes for radio-astronomy (ALMA) and for GNSS networks. (ii) non-supervised classification of X sources that have been detected by the XMM-Newton space telescope.

-- ''Astrophysical projects'' concerning the observation of double stars belonging to the Pre-Main Sequence (PMS) of the HR diagram, and of red dwarfs of the solar neighbourhood, with PISCO and PISCO2, to determine the orbits and the masses of those stars, which are still poorly known.