In this paper, we present methods for estimating precise geo-coordinates of objects observed in highly oblique video from an airborne camera in real time. High precision is achieved by registering observed video frames in real time to rendered views of the scene using stored reference imagery. The reference imagery includes previously collected satellite images and terrain maps that have been precisely aligned to geo-coordinates. We present methods that work for both nadir and highly oblique video imagery and under a variety of conditions where any one frame may not have enough information for accurate geo-registration.