The need to enhance the safety and efficiency of aviation systems has escalated with increasing aviation activity and competitiveness around the world. Weather, which is one of the principal factors affecting aviation performance, is acquiring ever more importance as aviation is poised to shift to futuristic paradigms such as free flight. Advanced systems and approaches to the surveillance of weather and the resultant generation of highly processed, detailed, accurate and reliable weather data, are becoming integral parts of support systems for navigation and air traffic management.