# Review of Photogrammetric and Lidar Applications of UAV
## 6 Discussion
### Discussion on Applications of UAVs
#### 6.2.3 Documentation of Historical Heritage  
Research on the documentation of historical monuments has been elaborated in the articles [124; 125; 126; 127; 128; 129; 130]. In [124], the authors dealt with the measurement and documentation of the Church of the Holy Spirit in Libechov, Czech Republic. The measurements were performed using a FARO Focus 3D X 330 laser scanner from the ground and supported by aerial photogrammetry. After processing, a derived document (two plan and four view drawings) and a 3D point cloud model of the church were created. In the article [125], the authors discuss the documentation of hard-to-reach places in historical buildings using an UAV. An octo-rotor UAV with Ouster OS0, Intel RealSense D435, Garmin lidar-Lite v3, Fermion URM37, and Sony A6500 sensors were used for data acquisition. Te Church of St. Anne and St. Jacob the Great in Stara Voda and St. Maurice Church in Olomouc in the Czech Republic were monitored. The authors of the article [126] obtained 3D reconstructions of cultural heritage using a BNU D8-1 UAV with a Canon EOS 5D Mark II digital camera and a Riegl VZ-4000 ground-based laser scanner. The [PERSON] family temple, located in Gutianvillage, China, was documented. Forty-five images of the object under study were taken from a height of 100 m AGL. The article [127] describes research on photogrammetric mapping of Mondujar Castle, located in Spain. The images were taken using a DJI Phantom 4 Pro+ with a 20 Mpix sensor. The result was a 3D model of the castle with an ortho-mosaic. The article [128] deals with monitoring dark spots in large historical buildings using micro-UAVs. The authors of [129] evaluated the quality of 3D models of monuments obtained using UAVs. The Chapel of the [PERSON], located in Sarajevo, was selected for the research. The UAVs used were the DJI Phantom 4 Pro and the DJI Mavic Pro. As a result, a 3D model with a resolution of 14 mm was created. In the article [130], the TLS and UAV technologies were compared. For this study, the site of the historical fortified tower Torre Zozzoli, located in Italy, was selected. Finally, a 3D digital reconstruction of the object was analyzed. The UAV finds its place in the documentation and 3D reconstructions of cultural heritage--historical monuments (churches, castles, historic fortified towers, and other cultural monuments) with large-scale dimensions and complex construction. Emphasis in research is placed on testing the potential accuracy with the subsequent generation of 3D models of historical monuments. The advantage of UAV remote sensing is mainly the coverage of high-lying parts of objects, the high detail, and the accuracy of models. UAVs are also used for documentation in archaeology [131; 132; 133; 134; 135; 136; 137]; the article [131] presents examples, possibilities, and results from aerial photogrammetry. Using UAV, the geometrical parameters of the archaeological sites of Clunia, Puig Rom, Vilanera and Cosa in Italy were determined, and their 3D models were created. The UAVs used for data acquisition during the period 2014-2021 were DJI Phantom 1 and DJI Phantom 2 with GoPro Hero 2 sensor, DJI Phanom 3 Advanced withMAPIR NGB sensor, MAPIR RE, Yuneecr Typhoon H with CGO-ET sensor, Parrot Anafi Thermal with FLIR Lepton 3.5 microbolometer sensor, DJI Mavic 2 Pro with Hasselblad 1\" sensor, MAPIR NGB, MAPIR RE, and DJI Mini 2. The authors of the article [132] discussed the creation of ortho-mosaics using an MD4-1000 UAV with a Sony NEX-7 RGB sensor to survey a 1.13 ha archaeological area in Torreparedones (Spain). Images were taken at heights ranging from 30 m to 80 m AGL and were processed in Inpho UASMaster. The RMSE with and without the use of GCPs are described in the results. In the conclusion, the ratio between RMSE and GSD of the UAV flights is presented as equal to value 5. The authors of the article [133] acquired archaeological documentation of six areas using a UAV designed by Gatoreye Unmanned Flying Laboratory with a lidar Scout-32 system.