3D Modelling of Sanggrahan Temple Using UAV Imagery and Terrestrial Photogrammetry Method

As evidence of ancient Majapahit civilization existence, Sanggrahan Temple has been officially recognized as a cultural heritage building by Indonesian government in 2019. Sanggrahan temple is located in Boyolangu District, Tulungagung Regency, East Java. Conservation efforts in Sanggrahan temple have been done by BPK Wilayah XI Jawa Timur. Many parts of the temple have been damaged and are believed in different condition from its past original design. Therefore, a 3D documentation of Sanggrahan Temple needs to be carried out to provide sufficient data for future conservation efforts. The photogrammetry method which utilizes UAV (Unmanned Aerial Vehicles) and terrestrial imagery offers great efficiency in terms of fieldwork and cost. The technique applied close range photogrammetry for image-acquisition and Structure from Motion (SfM) processing. There are roughly 500 images captured for 3D modelling purposes. For georeferencing and geometric accuracy assessment, the Ground Control Point measurement was also carried out using GPS receiver and total station. The result show that the combination of aerial (UAV) and terrestrial images provide complete 3D model. The generated 3D model can provide architectural views of the temple from all sides which help architects and archaeologists to interpret architectural design and detail of the building. Accuracy assessment based on the coordinate measurement shows that the 3D model results meet the specified accuracy standard of 10 cm which is suitable for many architectural drawing applications.