The objective of SET-207 was to extend the valuable lessons learned from SET-164 by developing and validating a robust and inclusive model for passive radar. A robust model-based approach to radar design and procurement is in accord with the approach desired by the more sophisticated military sensor research and planning agencies. In particular, SET-207 undertook three propagation measurement campaigns. One trial was performed in Florida, USA, the second in Switzerland and the third in South Africa. The three trial regions were significantly different in topology and climate and the analysis and associated models contribute greater insight into passive radar performance. The individual studies focus on propagation effects in VHF and UHF as a function of multipath and climatic conditions.