The increasing commercialization of unmanned aerial vehicles (UAVs) has opened the possibility of performing low-cost aerial image acquisition for the documentation of cultural heritage sites through UAV photogrammetry. This paper presents two case studies that illustrate the use of the DJI Phantom 4 normal UAV for aerial image acquisition, and the results that can be achieved using those images. A general workflow procedure of oblique image capturing and data processing of large data sets has been illustrated in the Prince of Wales Fort case study to create photogrammetric models and to generate orthophotos for condition assessment applications. The second case study provides insight on the possibility of using UAVs for post-disaster documentation when the accessibility and the availability of high cost equipment is of major concern. The results that were obtained from UAV photogrammetry of Nyatapola Temple and Bhairabnath Temple in Taumadhi Square in Nepal, which were damaged by the 2015 Gorkha earthquake, are presented and discussed.

The increasing commercialization of unmanned aerial vehicles (UAVs) has opened the possibility of performing low-cost aerial image acquisition for the documentation of cultural heritage sites through UAV photogrammetry. The flying of UAVs in Canada is regulated through Transport Canada and requires a Special Flight Operations Certificate (SFOC) in order to fly. Various image acquisition techniques have been explored in this review, as well as well software used to register the data. A general workflow procedure has been formulated based off of the literature reviewed. A case study example of using UAV photogrammetry at Prince of Wales Fort is discussed, specifically in relation to the data acquisition and processing. Some gaps in the literature reviewed highlight the need for streamlining the SFOC application process, and incorporating UAVs into cultural heritage documentation courses.

Keywords: Tin House Courtyard, laser scanner, photogrammetry, CAD drawings, BIM models, documentation The Tin House Courtyard is a property of the National Capital Commission (NCC) in Ottawa, Canada. The site is located within the ‘Mile of History’, a historical route running from Parliament Hill to the Governor General’s residence. Currently, existing assets are under intervention works that include several preservation and renewal actions. Within the broader project, one of the tasks before construction works started was the documentation of the set of facades. The Carleton Immersive Media Studio (CIMS) at Carleton University in Ottawa was commissioned by NCC to conduct the recording of the area. This paper describes the process undertaken from field work to the final deliverable to the client, as well as the issues faced in between. Nowadays, up to date surveying technologies have revolutionized the methodologies for cultural heritage documentation. In this regard, the recording strategy employed encompassed the use of photogrammetry, laser scanner, total station, as well as different pre and post processing software in order to generate the desired outcomes.