Jordan Journal of Civil Engineering

Extraction of As-Built Drawings Using Cell Phone Camera

Authors:

Nawras Shatnawi; Mohammed Taleb Obaidat;

Abstract:

The objective of this study was to introduce a new method for extracting as-built drawings of road intersections using cell phone camera through Close Range Photogrammetry (CRP). Three different cell phones of different resolutions (5MP, 8MP and 20MP) were used in this study to capture images for road intersections in Jordan. Calibration of cell phone cameras was done before the captured images were processed using iWitness and Agisoft software. For the purpose of accuracy assessment and result verification, 68 points were collected from the study area using differential GPS. The resultant as-built drawings extracted by this method were tested and compared with the collected GCPs from the field. Euclidian distance for different linear features in the 3D model was computed and compared with the extracted as-built drawing linear features. The results revealed that using 20MP, root mean square error RMSE in the x, y and z directions was 0.472m, 0.514m and 0.462m, respectively, which shows the feasibility of using such method for extracting road network intersection drawings. As the cell phone’s resolution increased, the potential accuracy of the as-build drawings increased. This method of extracting as-built drawings using cell phones will open the door for efficient and practical future applications.

Keywords:

Cell phone camera, Camera calibration, As-built drawings, Road intersections