A new approach to a multistatic passive radar sensor for air defense

A method to apply the latest technology in global navigation satellite systems (GNSS), in particular the U.S. NAVSTAR GPS (Navigation System for Timing and Ranging Global Positioning System) and the Russian GLONASS (Global'naya Navigatsionnaya Sputnikovaya Sistema), as a silent multistatic or parasitic radar for air defense is described. These satellite systems serving as navigational aids are well suited for low power radar applications due to the similarity and compatibility of the transmitted satellite signals with modern radar signals, such as spread spectrum modulation and pseudo random noise (PRN) codes. Preliminary flight tests with airships, jet and propeller aircraft, helicopter and anti tank missiles to study effects have been conducted.