James Miles, Hembo Pagi, Andres Uueni, Jüri Pärtna
Abstract Kaasan Church, in Tallinn, Estonia was built during the time of Peter the Great (1721) and is the oldest wooden sacral building in Tallinn. A building survey was conducted in January 2015 where a laser scan and photogrammetric survey was completed. One of the aims of the recording was to document the current situation of the building including the structure’s interiors and exterior. The end product being a spatially georeferenced point cloud which was used for plans and drawings, as well as 3D modelling and other interactive outputs. The paper will discuss the advantages that laser scanning and photogrammetry offer when compared to traditional survey techniques. With both types of recording taking place, the combination of the data has allowed for a precise and accurate representation of the church that goes beyond any form of recording that has previously taken place. The paper will therefore discuss the digital applications that these different methods provide when combined and it will show their usefulness in recording historical structures for Building Information Model (BIM) extraction. Using digital frameworks has provided sufficient and adequate information for further reconstruction and conservation planning and has been used in addition to the previous work carried out on site, such as dendrochronological recording. As our models were combined, the results gathered were used as a basis for a BIM, CAD model, drawings, cross-sections and a video animation as well as panoramic photography to enable 360 degree views. Rather than limit ourselves to one technique, the combination of various methods has allowed all aspects of the church to be recorded and the data gathered will be used for future renovations. Each of the stages used will be discussed as will the difficulties associated with merging these data types. Particular attention will be given within the discussion of the production of the BIM model. This will develop into a further explanation of how BIM can be used within cultural heritage and it will point out the advantages that can be gained for future archaeological research. The paper will not only highlight the end results produced but it will also discuss the workflow methodology used in combining the different data types to extract the BIM.
