APPLICATION OF DIGITAL TERRESTRIAL PHOTOGRAMMETRY IN ARCHITECTURAL CONSERVATION: THE MOSQUE OF ABDULLAH IBN SALAM OF ORAN

Abstract. Studies on the architectural heritage can now be supported by three-dimensional reconstruction of actual buildings. The 3D digital model can be an effective medium for documenting the current state of historic buildings but also to create a resource for researchers who conduct their analysis on historical evolution. Architectural photogrammetry has its own specifications in relation to other photogrammetric applications, however it meets these expectations.

The traditional approach requires the use of metric cameras but with the development of computational techniques, this requirement is overcome and opens the way for the use of non-metric camera.

The use of the shots that is no longer restricted to the parallel configuration of bundles, the images may be convergent, horizontal or oblique. Combining and modelling several cameras increasingly powerful in resolution and stability, has great scope and the same workflow can be used in varied applications.

ISPRS and ICOMOS created CIPA because they both believe that a monument can be restored and protected only when it has been fully measured and documented and when its development has been documented several times, i.e. monitored, also with respect to its environment, and stored in proper heritage information and management systems.

In this paper the 3D modelling of an important cultural site using terrestrial photogrammetric techniques for architectural preservation is presented. The site is the mosque of Abdullah Ibn Salam, Built in 1880 at the initiative of Simon Kanoui, also known as the Great Synagogue of Oran was inaugurated in 1918 only. It was one of the largest and most beautiful synagogues in North Africa. It was built with stone imported from Jerusalem. This place of worship became in 1975 the mosque of Abdullah Ibn Salam who was a rich Jew of Medina who was converted to Islam.

The structure is modelled using 321 oriented photos taken in five series of shots that cover all the façade and the interior of the building where more than 9200 points are created.

Also some orthophotos of the important elements are produced and used as materials in the final stage which is the edition in a 3D modelling software. And a video virtual tour is generated using this software.