The precision location of first responders deep within GPS denied infrastructure has been an elusive goal of the fre safety and emergency personnel community for well over a decade. The objective is to pinpoint location to within a few meters, over the course of tens of minutes. These coincidentally are nearly the same goals as found in guidance systems on tactical missiles, for which the solutions of choice today can cost $10,000 minimum, and have prohibitive size, weight, and power. Those same solutions were used in early proof of concept demonstrators for first responders, but were proven to be barriers (cost and size) to actual deployment.