Photogrammetry Standard

• High precision for objects up to 20m and more
• Insensitive against shocks and vibrations
• Robust for a large range of temperatures
• Easy to carry (system weight ca. 10kg)
• Usable in constrained spaces (e.g. car interiors)
• Usable in bright daylight as well as in near darkness

The Linearis3D Photogrammetry System Standard is perfectly suited to start off with optical 3D coordinate measurement. It is fast, precise and very easy to use. Typical Tasks are:

• Basic 3D measuring tasks
• Scanner orientation

Precision

Precision is defined using the German guideline VDI 2634. This guideline defines a cube as shown in Fig. 4 with seven scales. Each scale has four or five points whose distances are known with superior accuracy. The precision is defined by comparing the known distances with the distances computed by the photogrammetry system. Fig. 5 shows the length deviations for a 1m ³ cube. Fig. 6 shows results for 2m x 2m x 1.5m cube. The x-axes show the distances in mm, the y-axes the deviations in mm. Different colors indicate the deviations for the different scales. Results were obtained using the Linearis3D Professional system.

Precision is influenced among others by object size, object visibility, camera, camera positions, number of photos, software, user as well as length and number of scales. The configuration of the cube according to VDI 2634 is optimal for photogrammetric precision. Precision for other measurement configurations can be worse. Especially situations where measuring points can only be seen from a limited angle may produce greater deviations. For more information on precision of photogrammetric systems you can refer to Luhmann, p.111 (available only in German).