Simulation has gradually become the preferred method for designing complex systems. Testing any system in space was extremely expensive and very difficult. Most of designs nowadays by necessity, required simulations. Over time, this approach has become pervasive in many industries. Even in product developments, simulation has become the dominant method of design. A digital simulation of the environment that a system "lives" in is crucial in this modern simulation based design process. The accurate representation of this environment allows the designer to see how well the system he is...