## 3 Material and Methods  
### Materials  
As a first step, precise documentation of the shrine was carried out. Due to transportation difficulties, technologies that would minimize the cost of transporting special equipment were used. The first form of technology used was IBMR (Image based modelling and rendering) digital photogrammetry, which utilizes a high quality digital SLR camera and specialized software. Canon Mark II 5D (Oita Prefecture, Japan) (with a fixed 40 mm lens, sensor resolution 21 MPix) and Canon 450D (22 mm lens, sensor resolution 12.5 MPix) cameras were used. The Agisoft Metashape and RealityCapture softwares were used. To complement this, documentation was also done using a DJI Phantom 4 (Shenzhen, China) in 2018, and later in 2021 a DJI Mavic Pro (Shenzhen, China) drone was used (Figure 4). Videos were created and photographs were taken of the hard-to-reach roof areas. Iraq is still a no-fly zone, and a permit is required to operate a drone. Figure 4: Used instruments: (**a**) Laser scanners (from left)—TLS Faro Focus S150, TLS Leica BLK360, PLS GeoSlam Go. (**b**) Drones (from left)—DJI Phantom 4, drone DJI Mavic Pro. (**c**) Cameras (from left)—Canon Mark II 5D, camera Canon 450D, and Nikon D80. Another technology used was TLS. Easy-to-transport devices were used, i.e., the Leica BLK360 (Leica Geosystems, St. Gallen, Switzerland) terrestrial laser scanner, the Faro Focus S150 (FARO Technologies, Lake Mary, FL, USA), both of which are TLSs, and the GeoSlam Go (GeoSlam, Nottingham, UK) mobile personal laser scanner (PLS). The TLS Faro Focus S150 has a range 150 m, a declared precision of 2 mm, a scanning speed of more than 1,000,000 points per seconds, and is equipped with a camera. The TLS Leica BLK360 has a scanning speed of 360,000 points per second and 3D point accuracy of 6 mm per 10 m, a range of up to 45 m, and it is equipped with a camera for point cloud texturing. The PLS GeoSlam Go is a SLAM-type wearable scanner with a scanning speed of 40,000 points per second and accuracy of 1-3 cm per 10 m depending on the material type, with a range of around 30 m, and is not equipped with a camera. A big advantage of this type of work is that the devices are easy to transport; the Faro Focus S150 with a transport case weighs up to 5 kg, the BLK360 weighs only 1 kg, and the GeoSlam Go weight is similar. Documentation of the condition of the shrine began in January 2018. Within 4 days, a complete survey of the condition of the building was carried out with the equipment mentioned above (as TLS only Faro scanner was used). Valuable material of the condition of the sanctuary was obtained, which was then used to make 3D models and basic plans. The basic plans and a 3D model were created within a short timeframe so that work on the building could continue. This involved the clearing of the debris inside the building and the securing of its structural, which was already carried out in March 2018. At the same time, in March 2018, a second survey of the shrine was carried out and a geophysical survey was made using a GPR (ground penetrating radar), which served archaeological purposes and was used for excavation probes in the shrine's surrounding areas. These surveys were also used for the purposes of structural stabilization for the building and were processed in 3D for remote consultation. It should be noted that at that time there was heavy fighting with the Islamic State nearby. After data processing, two complete 3D models were created and used for the analysis of the works. From differences observed in the models, it was possible to determine the cubature of the collapsed parts of the building. The model was used to virtually fill in the missing parts with help of deep learning and modelling and, accordingly, after approval from the investor, the reconstruction work started. A virtual reality version was created from the models.