To provide a technology capable of applying a specified technique of vehicle position by image recognition, to many situations.

Reference image characteristic points to be used as a reference are extracted from a photographed image acquired by photographing a landscape of the periphery of a reference vehicle, and the position of the reference vehicle at the point of time, when the landscape of the periphery of the reference vehicle photographed is acquired by a reference position. Information showing the reference position is associated with reference pattern information, showing each position on the photographed image of the reference image characteristic points. Relative to a reference image characteristic point originated in an image of a fluctuating feature whose position on the photographed image fluctuates, corresponding to an environment among the reference image characteristic points, information showing that the characteristic point is originated in the image of the fluctuating feature is associated with information showing in each environment; and the fluctuation range possible for the photographed image of the reference image characteristic point correlated with the fact that the position on the photographed image of the fluctuating features fluctuates corresponding to the environment, and is recorded in a prescribed recording medium.