A time of flight camera provides two types of images simultaneously, depth and intensity. In this paper a computational method for background subtraction, combining both images or fast sequences of images, is proposed. The background model is based on unbalanced or semi-supervised classifiers, in particular support vector machines. A brief review of one class support vector machines is first given. A method that combines the range and intensity data in two operational modes is then provided. Finally, experimental results are presented and discussed.

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Time of Flight (TOF) cameras generate two simultaneous images, one of intensity and one of range. This allows to tackle segmentation problems in which the separate use of intensity or range information is not enough to extract objects of interest from the 3D scene. In turn, range information allows to obtain a normal vector estimation of each point of the captured surfaces. This article presents a semi-supervised spectral clustering method which combines intensity and range information as well as normal vector orientations to improve segmentation results. The main contribution of this article consists in the use of a statistical region merging as a final step of the segmentation method. The region merging process combines adjacent regions which satisfy a similarity criterion. The performance of the proposed method was evaluated over real images. The use of this final step presents preliminary improvements in the metrics evaluated.

Abstract. We show the results of the implementation of a preliminary algorithm for excluding ionospherically unsafe satellite geometries in Ground-Based Augmentation Systems Category I. Minimum knowledge of the ionospheric treat model is assumed and the assistance of the code-carrier divergence monitor is not considered. All the satellites in view above 5• in elevation are included in the computations. The inflation of the standard deviation of the vertical ionospheric gradient implements the exclusion. Full availability remains for a typical day in the site of La Plata Airport.