This paper presents a high level architectural specification of MedioGRID, a research project aiming at implementing a real-time satellite image processing system for extracting relevant environmental and meteorological parameters on a Grid system. The presentation focuses on the key architectural decisions of the GRIDaware satellite image processing system, highlighting the technologies for each of the major components. An essential part of managing a global Data Grid is a monitoring system that is able to monitor and track all the site facilities, networks, and tasks in progress, all in real time. Considering this issue the paper analyzes the possible grid monitoring approaches, proposes a solution and presents a set of monitoring results for the MedioGRID data management subsystem.