A source of opportunity aided detecting and ranging design with direct broadcasting satellites

During the last few decades radio detecting and ranging and microwave remote sensing have matured to become an important tool in the navigation and surveying of the Earth. Although quite different in design, all these systems have a common feature: they all carry their own transmitters (i.e. illuminating sources) with them. Besides these radar transmitters, a countless number of transmitters 'illuminate' the Earth nearly worldwide in a very broad frequency range. These transmitters usually offer a much lower incident power density in comparison to a radar transmitter, but many problems with multipath reception do show the occurrence of strong backscattered signals at these low power levels. Therefore, it is important to analyze these usually unwanted signals for their capability in remote sensing applications.