A navigation system comprising: a data acquiring unit for acquiring distance data showing a distance from a projection reference point of laser light to a distance measurement point (P 0), the distance being measured by a laser distance measuring device mounted in a moving body, angle data showing a projection angle (θ) of the laser light, coordinate data showing three-dimensional coordinates of the projection reference point of the laser light, the three-dimensional coordinates being measured by a coordinate measuring device mounted in the moving body, and image data containing a distance measurement point on an object taken by an image shooting device (20a,20b) mounted in the moving body; a coordinate calculating unit for calculating coordinates of the distance measurement point (P 0) on an image shown by the image data on a basis of the distance data that are acquired by the data acquiring unit, the angle data that are acquired by the data acquiring unit, the coordinate data that are acquired by the data acquiring unit, and a plurality of parameters showing an attitude of the moving body, wherein the plurality of parameters showing the attitude of the moving body comprises a roll angle of the moving body, a pitch angle of the moving body and a yaw angle of the moving body; an image matching unit for performing image matching on a pair of pieces of image data taken by the image shooting device at different shooting positions, and searching an image shown by one image data of the pair for a point corresponding to coordinates of a distance measurement point (P 0) on an image shown by the other image data of the pair, the coordinates being calculated by the coordinate calculating unit; and an attitude estimating unit for correcting initial values of the plurality of parameters showing the attitude of the moving body in such a way that a difference between coordinates of the distance measurement point (P 0) on the image shown by the other image data of the pair, the coordinates being calculated by the coordinate calculating unit, and coordinates of the corresponding point searched for by the image matching unit becomes small, and estimating values of the plurality of parameters which minimize the difference between the coordinates calculated by the coordinate calculating unit and the coordinates of the corresponding point searched for by the image matching unit as final values of the plurality of parameters showing the attitude of the moving body. a data acquiring unit for acquiring distance data showing a distance from a projection reference point of laser light to a distance measurement point (P 0), the distance being measured by a laser distance measuring device mounted in a moving body, angle data showing a projection angle (θ) of the laser light, coordinate data showing three-dimensional coordinates of the projection reference point of the laser light, the three-dimensional coordinates being measured by a coordinate measuring device mounted in the moving body, and image data containing a distance measurement point on an object taken by an image shooting device (20a,20b) mounted in the moving body; a coordinate calculating unit for calculating coordinates of the distance measurement point (P 0) on an image shown by the image data on a basis of the distance data that are acquired by the data acquiring unit, the angle data that are acquired by the data acquiring unit, the coordinate data that are acquired by the data acquiring unit, and a plurality of parameters showing an attitude of the moving body, wherein the plurality of parameters showing the attitude of the moving body comprises a roll angle of the moving body, a pitch angle of the moving body and a yaw angle of the moving body; an image matching unit for performing image matching on a pair of pieces of image data taken by the image shooting device at different shooting positions, and searching an image shown by one image data of the pair for a point corresponding to coordinates of a distance measurement point (P 0) on an image shown by the other image data of the pair, the coordinates being calculated by the coordinate calculating unit; and an attitude estimating unit for correcting initial values of the plurality of parameters showing the attitude of the moving body in such a way that a difference between coordinates of the distance measurement point (P 0) on the image shown by the other image data of the pair, the coordinates being calculated by the coordinate calculating unit, and coordinates of the corresponding point searched for by the image matching unit becomes small, and estimating values of the plurality of parameters which minimize the difference between the coordinates calculated by the coordinate calculating unit and the coordinates of the corresponding point searched for by the image matching unit as final values of the plurality of parameters showing the attitude of the moving body.