| 摘要 |
According to the present invention, position information about a position where material data were created is stored as altitude information of four bytes, longitude information of four bytes and latitude information of four bytes in the Spatial Coordinates area in UMID. In a novel format according to the present invention, there is stated at least identification information permitting to identify which the altitude information is, a distance from the center of the earth or a distance from the surface of the earth ellipsoid, measured by a predetermined geodetic coordinate system, using each of values "A" to "F" at one digit in hexadecimal notation, and the distance from the surface of the earth ellipsoid is stated as the altitude information. Thus, the format according to the present invention is upward compatible with the conventional UMID format and can be stated through effective use of meaningful altitude information acquired from outside. <IMAGE> |
