 Complete the following phrase:  The topography of Switzerland is such that certain areas and even radar shadows do not allow surveillance by permanently installed radars placed on mountains. In 1985, five mobile radar systems were purchased for 254 million Swiss francs in order to address this problem. Switzerland procured the mobile radars to improve the nations aerial warfare capability. However, the systems viability in a military operation was a controversial matter that was brought to attention and addressed in the initial attack waves of the 