The efficiency of off-axis adaptive astronomical systems is estimated for four astronomical sites: Paranal (Chili), Roque de los Muchachos (Canary Islands), San Pedro Mártir (México) and Observatoire de Haute Provence (France). The efficiency of interest is considered through the Strehl ratio of the corrected image calculated for V, J and K bands and for 8-m class telescopes. The experimental o...

I propose to use as a window the dark core of an optical vortex to examine a weak background signal hidden in the glare of a bright coherent source. Applications such as the detection of an astronomical object, forward-scattered radiation, and incoherent light are described whereby signal enhancements of at least 7 orders of magnitude may be achieved.

The astronomical database SIMBAD developed at the Centre de Donn ees de Strasbourg CDS currently contains about one million objects stellar and non stellar all described by heterogeneous data bibliographical references measurements and identi ers SIMBAD supplies the existing links between the di erent synonym names of one object and describes astronomical objects with information coming from th...

In this proposed thesis, I will develop efficient non-parametric methods for parameter estimation in large databases of high-dimensional, noisy data. Specifically, I plan to continue exploring the efficacy of the diffusion map method of data transformation, used in conjunction with the Nyström extension, in uncovering underlying structure in complicated, high-dimensional data sets. I will explo...