# Review of Photogrammetric and Lidar Applications of UAV
## 6 Discussion
### Discussion on Applications of UAVs
#### 6.2.1 Mapping and Surveying  
The authors of [67] tested a lidar system that was placed on a helium balloon on Sherman Island near Antioch, California. They used a Velodyne HDL-32E lidar scanner with a pulse frequency of 700 kHz and a range of up to 100 m at a flight height of approximately 25 m AGL. The RMSE had a value of 0.09 m. The nominal density of points was 1000 points/m\({}^{2}\). In their publication [68], the authors investigated the detection of the globalized probability of boundary (gPb) contours using a UAV. They mapped three rural areas in Germany, France, and Indonesia. In Toulouse, France, data were captured with direct georeferencing using a DT 18 PPK and a DT-3 Bands RGB camera, with a resulting GSD error of 3.61 cm. In Amtsvenn, Germany, a GerMAP G180 UAV model with a Ricoh GR camera was used with a resulting GSD error of 4.86 cm. Data in Germany and in Indonesia were captured using GCP. For mapping in Lunyuk, Indonesia, they used a DJI Phantom  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Country** & **Institution** & **Prohibition (without Permission)** & **References** \\ \hline \multirow{5}{*}{Slovak Republic} & & - & flying with UAV if a pilot is under the influence of psychoactive substances - - & flying at an altitude of 120 m or more - \\  & & - & flying with UAV that has a pulse or rocket engine - & [31; 32; 33] \\  & & - & flying without visibility of the UAV with the naked eye - & flying for the purpose of commercial air transport - \\  & & - & flying for the purpose of spraying chemicals or dropping objects \\ \hline \multirow{5}{*}{Czech Republic} & & - & flying in densely populated areas - - & flying at an altitude of 120 m or more - \\  & & - & flying for the purpose of transporting persons - - & flying for the purpose of dropping objects - & [35; 36; 38; 40] \\  & & - & flying over gatherings of people and emergency interventions - & - \\  & & - & flying within 30 m of persons - & \\  & & - & flying near controlled and uncontrolled airports & \\ \hline \multirow{5}{*}{Poland} & & - & flying at an altitude of 120 m or more - - & \\  & & - & flying without visibility of the UAV with the naked eye - & \\  & & - & flying with UAV heavier than 25 kg - & [41; 42; 43] \\  & & - & flying around airports within 5 km - & \\  & & - & flying 100 m or less from populated areas and 30 m or less from people, - & \\  & & - & vehicles, and animals & \\ \hline \multirow{5}{*}{Hungary} & & - & flying at an altitude of 120 m or more -  
3 UAV with a Sony EXMOR FC300S camera. The resulting GSD was 3.00 cm. The measurements resulted in three ortho-images of different scales. The authors of [69] demonstrated improvements to the UAV multispectral mapping technique for higher resolution imagery in the terrain over the Indian River Lagoon along the central Atlantic coast of Florida. They use a Parrot Bluegrass quadcopter with a Parrot Sequoia+ multispectral sensor and a DJI Phantom 4 Pro quadcopter equipped with an RGB CMOS camera sensor. As a result, data were collected from a flight altitude of 120 m from which ortho-mosaics, Digital Surface Model (DSM), Digital Elevation Model (DEM), and point clouds were produced. In the study [70], waterflowl in the west of the Songnen Plain, Jilin Province, China, was monitored using UAV technology. A Phantom 4 Advanced UAV equipped with an FC6310 camera and a Nikon MONARCH 82 ED-A monocular telescope were used for this survey. [PERSON] et al. [71] used the UAV to monitor and calculate the stockpile volumes of material from sorted waste collection, producing 3D models from point clouds. They used a DJI Phantom 4 Pro UAV. [PERSON] et al. [72] monitored coastal and beach changes using a DJI Matrix 600 and a Spark UAV to produce DTM and ortho-images, and the authors [73] used the DJI Phantom 2 UAV to map flood risks. The use of UAV photogrammetry or lidar technology in the field of mapping and surveying depends on various factors.