The most demanding requirements for radar systems have so far nearly always resulted from military objectives; civil applications then benefit from the achieved results. Developments in the available technology, particularly within the areas of highly integrated semiconductor technology for digital signal processors, miniaturised microwave integrated circuits (MMICs) and efficient microwave computeraided design methods, have enabled ever more demanding procedures and concepts to be achieved. The theoretical fundamentals and evaluation possibilities improved simultaneously, especially by the development of computers and programs. The use of powerful personal computers with program systems such as MATLAB or Mathematica is now very common.