An optical data processing apparatus comprising: an optical data obtaining part which obtains a laser scan point cloud obtained by a laser scanner mounted on a moving body in a moving condition and image data of a photographed image photographed by a camera mounted on the moving body in a moving condition; a point cloud feature point calculating part that extracts, from the laser scan point cloud, feature points of an object from which the laser scan point cloud is obtained, and then calculates a point cloud feature point image by imaging the extracted feature points; a delay time obtaining part that obtains Δt when the camera photographs with a delay Δt when the camera is commanded to take a photograph at a time T; and a projection part which makes a projection image, the projection image made by overlapping and projecting the point cloud feature point image as viewed from a specific viewpoint and an image feature point image, in a state in which directions of viewing lines are aligned, the image feature point image obtained by extracting feature points from the photographed image, wherein relationships of exterior orientation elements of the laser scanner and the camera in the moving body are known, the projections are performed multiple times by changing a viewpoint position of at least one of the point cloud feature point image and the image feature point image so that multiple projection images are made, and Δt is calculated in conditions in which difference in overlapping degree of the point cloud feature point image and the image feature point image in the multiple made projection images is minimal or is not greater than a threshold value. an optical data obtaining part which obtains a laser scan point cloud obtained by a laser scanner mounted on a moving body in a moving condition and image data of a photographed image photographed by a camera mounted on the moving body in a moving condition; a point cloud feature point calculating part that extracts, from the laser scan point cloud, feature points of an object from which the laser scan point cloud is obtained, and then calculates a point cloud feature point image by imaging the extracted feature points; a delay time obtaining part that obtains Δt when the camera photographs with a delay Δt when the camera is commanded to take a photograph at a time T; and a projection part which makes a projection image, the projection image made by overlapping and projecting the point cloud feature point image as viewed from a specific viewpoint and an image feature point image, in a state in which directions of viewing lines are aligned, the image feature point image obtained by extracting feature points from the photographed image, wherein relationships of exterior orientation elements of the laser scanner and the camera in the moving body are known, the projections are performed multiple times by changing a viewpoint position of at least one of the point cloud feature point image and the image feature point image so that multiple projection images are made, and Δt is calculated in conditions in which difference in overlapping degree of the point cloud feature point image and the image feature point image in the multiple made projection images is minimal or is not greater than a threshold value.