Abstract
The surveying of archaeological relics is a complex process in that it requires the combination of several previously defined representation techniques. The example of the Tipasa's nameless temple allows the evaluation of the rational and pertinent use of new means of surveying and representation requiring an architectural knowledge of the subject that helps orient the choice and combination of acquisition methods. In this case, two techniques were combined: topography for the general survey and georeferencing, and photogrammetry for the surveying of architectural details. The final result allows, firstly, for the design of a georeferenced, stone-by-stone survey of the relics at a scale sizable enough to grasp the general large-scale conception by recognizing and identifying the main elements which constitute the temple. Then the use of photogrammetry allowed the elaboration of a significant 2D and 3D database of the architectural elements necessary to identify of the type and order of the construction, and will contribute to the researches carried in North African places of worship.
TopHistorical Notes On The Site And Description Of The Current Situation
The nameless temple is located at a high point of Tipasa’s western park in Algeria. Tipasa is a historical and touristic site situated 70km from Algiers, and is part of UNESCOs World Heritage sites since 1982 (Figure 1).
Key Terms in this Chapter
Italic Temples: Sanctuary characterized by raised temple on a rectangular podium elevated ground accessible by an axial stairs conducting to the pronaos and the cella which hosts the statue of the divinity.
Point cloud: A set of three-dimensional distributed points which result from a laser or photogrammetry scan. Each point cloud is calculated by matching several photographs (in the case of photogrammetry survey) so as it corresponds to a point of the surface of the surveyed object. The density of a point cloud is dependent on the quantity and quality of the photos taken, but also on the followed protocol of the shooting.
Geometric Primitives: Basic forms which constitute a geometric element. The identification of geometric primitives helps identify the size and shape of an object and enter the special relations linking it.
Georeferencing: A process that consists in giving a geographic dimension for images or vectors. Such transformation will place the projected entities in a real world coordinate system according a projection system. The projected objects will have a vertical relationship in order to be layered in a GIS software for later analysis and geoprocessing.
Virtual Anastylosis: Reproduction, through the use of the digital tool, of the collapsed parts of a construction with elements found on location. The reproduction is based on a methodical analysis that enables the participants to accurately replace the elements.
Extrusion: Method, which allows to raise the lines or polygons of a 2D profile along a selected trajectory that forms the axis of symmetry. The simplest extrusion example of a square following a line perpendicular to the plan will give the thickness and produce a cube.
Mauretania Caesariensis: Geographical area of North Africa formerly province of ancient Rome and currently corresponding to the center and west of Algeria.
Africa Proconsularis: Geographical area of North Africa, ancient Roman province currently corresponding to Tunisia, a part of Algeria and a part of Libya.