A morphological analysis of historic buildings entries using affordable photogrammetry techniques: Old Tripoli, Lebanon

This article documents and compares selected arched and vaulted entrances of historic buildings in Old Tripoli, Lebanon. The aim is to capture the entrances and their immediate context using low-cost photogrammetry to contribute to the safeguarding process of these endangered monuments. The possibilities of recording the micro as well as macro elements of entry spaces for specific typologies, such as schools, khans, residences and places of worship, are explored in the context of a city under the threat of armed conflict, neglect and environmental risks. Micro-scale analysis focuses on forms such as shape, height, and street width, regardless of the building entry’s function. Macroscale analysis considers a typical barrel-vaulted tunnel entry to a historic, residential sector of the city where a 3D photogrammetry model demonstrates the form and function of this network of spaces. The research methodology is divided into two processes: the first is a photographic survey of the entrances using a mobile phone camera, followed by the use of both free and educational licensed photogrammetry software to align and develop the captured images into 3D digital models. The second process is conducting interviews with selected stakeholders, such as historians and building custodians to elicit their stories compared to our understanding of the digitally captured 3D buildings and the wider historic city of Tripoli. We argue that affordable photogrammetry methods are necessary and effective. Acknowledging the limitations of these methods, this article argues that the outputs of the implemented methods not only contribute to the identification of the significance of these monuments, but also provide a valuable set of information to assist in the different processes of safeguarding these endangered assets.