Can hundreds of unrelated satellites create a GPS backup?

The head of the Space Development Agency wants to use proliferated low-Earth orbit satellites for navigation when GPS is unavailable. As adversaries develop tools that can jam or spoof Global Positioning System signals, the military has prioritized the development of alternative sources of positioning, navigation and timing data for the war fighter. Solutions range from using real-time drone imagery to chip-scale atomic clocks, but at the Association of the United States Army conference Oct. 16, Acting Director Derek Tournear threw out another idea: using the positioning and timing data of the hundreds of satellites his agency plans to put in orbit for navigation. More

(Source: C4ISRNet - Nov 30)