In this paper, we propose an omni-directional depth measurement method using hyperbolic mirror cameras and projectors to develop circumference sensing function for autonomous mobile systems, virtual reality systems, and so on. In this method, we use two omni-directional cameras to take images of patterns projected by projectors, and estimate distances from cameras to objects by the stereo method. Especially, we use the space encoding method, vertical lines and small points as projected patterns, and we discuss appropriate pattern projection for distance measurement with omni-directional cameras. As the results of experiments, small points projection can measure distances more accurately than other projection, and we can show the effectiveness of proposed method by measuring 3D depth surrounding cameras using multiple projectors.