Digital Close Range Photogrammetry Technique Research Articles

Estimating a mathematical formula of soil erosion under the effect of rainfall simulation by digital close range photogrammetry technique

A new design of soil erosion and rainfall simulator is presented at this study as an attempt to deduce a mathematical formula of soil surface erosion phenomenon to describe the behavior of the sandy soil under the rainfall simulation, soil deformation such as the gullies and surface eroding rills are monitored by the Digital Close Range Photogrammetry (DCRP) technique that includes capturing digital images by a smart cellphone camera, and a Terrestrial Laser Scanner (TLS) to digitalize the soil surface as a point cloud data to produce Digital Elevation Models (DEM) with an accuracy reaches 0.10mm with the watershed, color relief, 3D surface model. The results show that the mentioned methods give a typical digital surface feature express especially of using geometrical adjustment that controls the orientation of the digital surface. The SIFT technology of the digital imaging feature detection achieves accurate results despite its small cost, 12% if compared to the TLS method. As a result of the statistical observations, a simple mathematical formula was generated through the DCRP technique that describes the sandy soil behavior under a hybrid technique of rainfall simulation as a relation between the eroding rate and the duration through the different gradient slopes.

Estimating a mathematical formula of soil erosion under the effect of rainfall simulation by digital close range photogrammetry technique

A new design of soil erosion and rainfall simulator is presented at this study as an attempt to deduce a mathematical formula of soil surface erosion phenomenon to describe the behavior of the sandy soil under the rainfall simulation, soil deformation such gullies and surface eroding rills are monitored by the Digital Close Range Photogrammetry (DCRP) technique that includes capturing digital images with a smart cellphone camera, and a Terrestrial Laser Scanner (TLS) to digitalize the soil surface as a smart point cloud data to produce Digital Elevation Models (DEM) with accuracy reaches 0.10 mm 3D surface model. The results show that the mentioned methods give typical digital surface feature express especially of using geometrical adjustment that controls the orientation of the digital surface, the digital imaging feature detection technology achieves accurate results despite its small cost compared to the laser scanner that the cost of imaging equipment and software are used did not exceed 12% of TLS cost. Results of the statistical observations, a 3 order polynomial mathematical formula was generated through the digital photogrammetry method that describes the sandy soil behavior under the rainfall simulation as a relation between the eroding rate and the duration through the different slopes.

Study the accuracy of digital close range photogrammetry technique software as a measuring tool

This paper presents a study of accuracy of a digital technique that uses a computer photogrammetric software which is PhotoModeler, this one based mainly on two mathematical theories to determine some measurement quantification, Direct linear Transformation (DLT) and Scale Invariant Feature Transform (SIFT) will be discussed as an explanation of the software technology. A set of laboratory experiments were prepared as a comparison with the traditional techniques, a try to assess the highest possible accuracy of the software and to demonstrate if it matches the proposed standard values, The pilot recommendations were also taken into account in the conduct of the tests as well as in the creation of projects by the software. These experiments focused on study of the accuracy of length monitoring and size measurement, the observation of the ground cartesian coordinates as well as the camera format size calculation. The results show that this technique could be relied upon effectively in some different measurements rather than traditional methods.

THE MEASUREMENT OF FULL SCALE STRUCTURAL BEAM-COLUMN CONNECTION DEFORMATION USING DIGITAL CLOSE RANGE PHOTOGRAMMETRY TECHNIQUE

Measurement and monitoring of structural components such as beams and columns under loading are important in structural analysis and design assessment. Presently, the assessment on structural components on deformation or displacement measurement is carried out through LVDTs or dial gauges. The LVDTs or dial gauges were installed in contact with the structural components, also known as contact method. However, present contact method is subjected to some limitations such as s displacement points of measurement are highly depend on the position of LVDTs available, reliability of LVDTs and dial gauges to measure during the experiments due to possibility of damage sensors and consumption of time on the installation the sensors. Due to the limitations of contact method, this study demonstrates the use of a noncontact method using digital close range photogrammetry technique to measure the deformational behaviour of full-scale structural beams and columns. In this study, a full-scale load tests on structural components were performed under laboratory conditions. A series of digital images of the structural beams and columns under various loads were captured using Nikon DSLR cameras. The digital images then processed and analyzed using digital close range photogrammetric technique to measure and extract the magnitude of the structural beam and column displacements. The deformation and displacement of beam and columns have been validated by comparing the photogrammetric outputs against the results obtained from the LVDTs. The statistical analysis shows the differences obtained between the photogrammetric technique and contact method used were not significant.

Designing building façades for the urban rebuilt environment with integration of digital close-range photogrammetry and geographical information systems

Abstract Ankara, the capital of Turkey is situated in the middle of Anatolia. The center of Ankara is an important commercial area and a pedestrian shopping center. A main road, Ataturk Boulevard, bisects the central area of the city and this street contains a variety of building types which reflect the identity of the city. However in recent years, the urban environment of this street has been affected by the urban sprawl and visual pollution. This paper presents an innovative approach to a project that aims to re-design and renovate the existing building facades in the Boulevard in harmony with the existing environment. The project uses high resolution digital camera images from a calibrated digital camera and uses a digital close-range photogrammetry technique with integrated geographical information systems.