The Operational Multiscale Environment Model with Grid Adaptivity (OMEGA) and its embedded Atmospheric Dispersion Model is a new atmospheric simulation system for real-time hazard prediction, conceived out of a need to advance the state of the art in numerical weather prediction in order to improve the capability to predict the transport and diffusion of hazardous releases. OMEGA is based upon an unstructured grid that makes possible a continuously varying horizontal grid resolution ranging from 100 km down to 1 km and a vertical resolution from a few tens of meters in the boundary layer to 1 km in the free atmosphere. OMEGA is also naturally scale spanning because its unstructured grid permits the addition of grid elements at any point in space and time. In particular, unstructured grid cells in the horizontal dimension can increase local resolution to better capture topography or the important physical features of the atmospheric circulation and cloud dynamics. This means that OMEGA can readily adapt its grid to stationary surface or terrain features, or to dynamic features in the evolving weather pattern. While adaptive numerical techniques have yet to be extensively applied in atmospheric models, the OMEGA model is the first model to exploit the adaptive nature of an unstructured gridding technique for atmospheric simulation and hence real-time hazard prediction. The purpose of this paper is to provide a detailed description of the OMEGA model, the OMEGA system, and a detailed comparison of OMEGA forecast results with data.

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For a specialized device or setup in case of any practical communication related problem definition, a sound communication system consisting of the necessary integral parts is very crucial. As such, the design and an analysis of the various communication system is very critical as it directly effects the performance of the device and also reveals the inherent capacity of the system to produce the desired results. In this respect our topic for this paper is the design and analysis of different digital communication systems with a view to determine the most effective system considering all the parameters so that it can be used for important communication based problems and situations. In the next section we will mainly focus on the design processes of various systems, the theory involved, the simulation results, some special techniques of error correction and also the error performance of the systems.