Multi-static entirely passive detection of moving targets and its limitations

The concept of fully passive detection of moving targets based on thermal radiation in the microwave range is presented. The classical approach for target detection, based on a single receiver, allows detection of the target in the case when its temperature is significantly higher than the background. The fundamental problem, i.e., distinction between stationary and moving targets, may be solved using a multilateral system, and examining the range-Doppler correlation function among signals obtained from diverse sensor localisation in the multi-static constellation. The range equation and some limitations of the presented method are discussed.