Systems, methods, and apparatus for geo-location using known target co-calibration are disclosed. In one or more embodiments, a method for geo-location of a target involves receiving, by at least three elements on a vehicle, at least one station signal from at least one station in a known direction from the vehicle. The method further involves calculating, by at least one processor, a roll estimate and a pitch estimate of the vehicle using at least one station signal. Also, the method involves receiving, by at least three elements on the vehicle, at least one target signal from the target. Further, the method involves calculating, by at least one processor, an azimuth direction and an elevation direction of the target using the roll estimate, the pitch estimate, and at least one target signal.