Close-Range Photogrammetry is an accurate, cost effective technique of collecting measurements of real world objects and conditions directly from photographs. Photogrammetry utilizes digital images to obtain accurate measurements and geometric data of the object or area of interest, in order to provide spatial information for engineering design, spatial surveys or 3D modeling. The benefits of close-range photogrammetry over other field procedures are: Increased accuracy; complete as-built information; reduced costs; reduced on-site time; and effective for small and large projects.

Applications are abundant. The hull of a ship, the curve of a fender, the direction of a cell tower antenna - are no problem to create accurate CAD models in MicroStation or AutoCAD from digital photographs taken from different perspectives with a consumer grade camera. Close range photogrammetry is being used in process and manufacturing, petrochemical, power, pulp and paper, equipment design and installation, shipbuilding, construction, forensics, civil engineering, architecture, and topographic surveys.

Photography for close-range photogrammetry requires photographing a site using a compact, hand-held, digital camera with known characteristic (lens focal length, imager size and number of pixels), taking multiple, overlapping images from different perspectives. By indicating three object points in two images of the same scene, and indicate a known dimension, other 3D points in the images can be determined and enable the production of accurate as-built measurements and 3D models.

Close-range photogrammetry does require software that pulls all the various components into a system that automates the functions and makes the technology practical. The most robust and practical close-range photogrammetry software is Vexcel Corporation’s (Boulder, Colo.) FotoG version 5.2 software because of its ability to provide measurements without physical contact of the object, its speed and accuracy, using straightforward data gathering with inexpensive equipment in the field and typical CAD programs in the office.

Close-range photogrammetry removes the need to physically access each point at which a measurement is required, replacing field measurements with image measurements. Basically, if you can see it, the exact location can be determined from the photography. Photogrammetry allows the field measurements to be done at the office. This reduces the required on-site period to the time required for obtaining photography of the area of interest. Close-range photogrammetry is a fast, cost-effective, accurate means to create 3D models, as-built designs and an alternative to traditional surveying techniques.