Time for phased array GPS receivers to detect the origin of the signals. Part of the GPS is knowing where the satellites are so they certain know where to look.
Also, bad news, the cost of inexpensive computer vision systems means it's possible to make drones that can use roads and maps to localize them. Computer vision and differences in temperature and lack of vegetation visible in IR make this relatively cheap. Possibly combine a path-finder drone to get to the building(s) of interest and have it transmit a laser back along the expected path of a missile to bring in the muscle, no RF required.