مریم احمدی باغ

Although close range photogrammetry has not been a common approach in the Civil Engineering field especially the displacement monitoring of large scale constructions, many project successfully used this approach and as a result this method have a high potential in this application. Nowadays, as a result of improving the computer vision and photogrammetry techniques implemented in many software and high resolution images captured by the off-the-shelf digital cameras, the use of progressive photogrammetric techniques instead of traditional displacement methods become more resendable. This paper aims to explain a novel method for monitoring of the large scale constructions based on visual inspection. This method can specify the displacement of the constructions based on photogrammetric and computer vision methods using drones. The evaluation of the proposed system is done on long wall in two epochs with a short time interval. Having known the zero displacement for this construction, the difference between the coordinates of some sample points obtained in first epoch and the second epoch, 1.89 mm, shows the accuracy of the proposed system in detecting displacement. Moreover, the accuracy of this photogrammetric method was investigated by developing a tool which manually provides a known displacement between two points in the second epoch. The displacements of these points were estimated using the proposed method and compared with the known displacement. The accuracy for this method, less than 2 mm, can confirm the capability of this method for such applications.