الفهرس 
Background of 3D Modelling using Laser ScannerOnly 14 pages are availabe for public view
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Abstract
At the last decade, the terrestrial laser scanning technique became a suitable alternative to create a 3D model for any object instead of the (image-based technique). This suitability is related to different factors; simplicity, high progress of data acquisition, and direct recovering of interest points on the object without more measurements or processing. Although the TLS is recommended as a highly accurate instrument which is adequate for various applications, maintaining high accuracy of acquired huge data in the presence of some errors (instrumental, object-related, environmental, methodological, and scanning geometry) is a major challenge.
Therefore, the main objective of this research work is the investigation of the sources which could be controlled, these sources are;
- Scanning geometry which is the orientation (angle and range) of the object related to the scanner.
- Methodological errors which includes; the chosen registration or geo-referencing techniques, survey method, used soft wares and user experience.
The applied work methodology was depending on; the accuracy assessments of the output product whether they are point clouds or models to fulfil the required objective. In this context; two experiments (Outdoor and Indoor) were implemented using two designed calibrated targets to evaluate the geometric accuracy of the distances on the scanned targets under different geometric conditions. On the other side, the registration and geo- referencing techniques, surveying planning, choices of the suitable programs and the user experience was investigated through two different 3D modelling applications (small statue and large water structure).
The concluded results show that; the orientation of the object is not affecting the accuracy of the output point clouds measurements with in 7m range. All the RMSE are ranging from 0.8mm to 2mm with orientation angles from 0˚ to 50 ˚. For the long distances, the results were different. The scanning accuracy is directly decreased with the increase of used orientation angle; the RMSE value was nearly 10mm. Through the implementation of two different applications, different techniques of registration and geo-referencing were applied and various programs were used. For both applications, the Trimple Realworks adopted better result than the Scene software from the point of view of accuracy, simplicity, and organization. The Geomagic software was preferable than the Trimple Realworks based on the specialized modelling capabilities for the modelling of Three-dimensional irregular objects (small statue). The Trimple Realworks is suitable for the modelling of the systematic engineering applications (barrage). The accuracy assessment of the created 3D model of the Indoor application (small statue) obtained a result of (1.2 mm) total RMSE. On the other side, the accuracy assessment of the created 3D model of the Barrage obtained a result of 10.94mm total RMSE.