Photogrammetric error sources and impacts on modeling and surveying in construction engineering applications

Table 1 Behaviors of photogrammetric modeling

Factor	Behavior
Distance	Farther distance, lower accuracy (40 m: 6 ~ 10 cm)
Number of overlapping photos	The larger number of overlapping photos, the better accuracy
Intersection angle	The closer to 90°, the better accuracy
Angle of incidence	The closer to 0°, the better quality of images, so the better accuracy
Camera model	Higher end, higher accuracy
Resolution	Strong correlation with accuracy (raise by 1.6% per 1 MB increase)
Features (texture)	More features, higher accuracy; higher accuracy by colorful texture than grey/plain texture
Focal length	Longer focal length, higher accuracy; set to obtain optimum coverage
Camera lens	Less distortion, higher accuracy