24,091 research outputs found
Adaptive polarimetric image representation for contrast optimization of a polarized beacon through fog
We present a contrast-maximizing optimal linear representation of
polarimetric images obtained from a snapshot polarimetric camera for enhanced
vision of a polarized light source in obscured weather conditions (fog, haze,
cloud) over long distances (above 1 km). We quantitatively compare the gain in
contrast obtained by different linear representations of the experimental
polarimetric images taken during rapidly varying foggy conditions. It is shown
that the adaptive image representation that depends on the correlation in
background noise fluctuations in the two polarimetric images provides an
optimal contrast enhancement over all weather conditions as opposed to a simple
difference image which underperforms during low visibility conditions. Finally,
we derive the analytic expression of the gain in contrast obtained with this
optimal representation and show that the experimental results are in agreement
with the assumed correlated Gaussian noise model
Image Reconstruction in Optical Interferometry
This tutorial paper describes the problem of image reconstruction from
interferometric data with a particular focus on the specific problems
encountered at optical (visible/IR) wavelengths. The challenging issues in
image reconstruction from interferometric data are introduced in the general
framework of inverse problem approach. This framework is then used to describe
existing image reconstruction algorithms in radio interferometry and the new
methods specifically developed for optical interferometry.Comment: accepted for publication in IEEE Signal Processing Magazin
Applications of artificial intelligence to mission planning
The scheduling problem facing NASA-Marshall mission planning is extremely difficult for several reasons. The most critical factor is the computational complexity involved in developing a schedule. The size of the search space is large along some dimensions and infinite along others. It is because of this and other difficulties that many of the conventional operation research techniques are not feasible or inadequate to solve the problems by themselves. Therefore, the purpose is to examine various artificial intelligence (AI) techniques to assist conventional techniques or to replace them. The specific tasks performed were as follows: (1) to identify mission planning applications for object oriented and rule based programming; (2) to investigate interfacing AI dedicated hardware (Lisp machines) to VAX hardware; (3) to demonstrate how Lisp may be called from within FORTRAN programs; (4) to investigate and report on programming techniques used in some commercial AI shells, such as Knowledge Engineering Environment (KEE); and (5) to study and report on algorithmic methods to reduce complexity as related to AI techniques
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