Device for calculating positional data of standard points of a photogrammetric target

A method for calculating positional data of standard points of a target of photogrammetric analytic measurement comprising:

• a first step that photographs an object of photogrammetric analytic measurement together with a target that has a first standard point and a second standard point and a third standard point, by a camera, to obtain an image,
• said first standard point, said second standard point and said third standard point of the target being positioned with a predetermined interval between,
• at least one assistant point being provided on said target on each of a first straight line, connecting said first standard point and said second standard point, and a second straight line, connecting said second standard point and said third standard point,
• said first straight line and said second straight line defining a first predetermined angle therebetween, said first predetermined angle appearing as a second predetermined angle in said image;
• and
• a second step that, when said second predetermined angle is within a predetermined limit that is determined in accordance with the possible second predetermined angles that can appear in an image that includes said target having said first predetermined angle, calculates each two-dimensional coordinate value of said first standard point, said second standard point and said third standard point in a photograph coordinate system that is a two-dimensional coordinate system of a photographed image photographed by said camera.

A recording medium in which a calculating program of standard points of a target of photogrammetric analytic measurement is stored, said target having a first standard point and a second standard point and a third standard point, and said target being photographed together with an object of photogrammetric analytic measurement;

• said first standard point, said second standard point and said third standard point of said target being positioned with a predetermined interval between,
• at least one assistant point being provided on said target on each of a first straight line, connecting said first standard point and said second standard point, and a second straight line, connecting said second standard point and said third standard point,
• said first straight line and said second straight line defining a predetermined first angle therebetween, said first predetermined angle appearing as a second predetermined angle in said image,
• said calculating program comprising:
• a values of two-dimensional coordinate calculating routine that, when said second predetermined angle is within a predetermined limit that is determined in accordance with the possible second predetermined angles that can appear in an image that includes said target having said first predetermined angle, calculates each two-dimensional coordinate value of said first standard point, said second standard point and said third standard point in a photograph coordinate system that is a two-dimensional coordinate system of a photographed image.