## 2 Material and Methods
### UAV Process Drone Photogrammetry  
After determining the location for the mapping area, a process of taking aerial photos with Unmanned Aerial Vehicles (UAV) using the drone was carried out. Table 3 presents the specifications of the equipment and the parameters of the autopilot track mode used.  
A total of 4853 aerial photos were produced using aerial image recording with drones, with a resolution of 4000 \(\times\) 3000 pixels. Figure 5 shows some of the successful aerial photos taken.  
The thirteen drone flights were planned when designing an application for autopilot settings. However, 16 drone flights were used during the actual implementation on the field due to the adjustment of wind speed conditions. Each drone flight took 18 to 23 min to complete. Gimbal orientation was 90', the front lap and side lap values were 85 per cent using the 3D crosshatch method, the GSD was 3.3 cm/px, and the flight speed was 5 m/s.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Object Type** & **Latitude** & **Longtitude** & **Description** \\ \hline Bridge 1 & \(7^{\circ}43^{\prime}43.10^{\circ}\) S & \(109^{\circ}1^{\prime}13.29^{\circ}\) E & Budi Utomo street \\ Bridge 2 & \(7^{\circ}43^{\prime}36.14^{\circ}\) S & \(109^{\circ}1^{\prime}16.81^{\circ}\) E & Step street \\ School & \(7^{\circ}43^{\prime}38.54^{\circ}\) S & \(109^{\circ}1^{\prime}6.51^{\circ}\) E & Budi Utomo street \\ House 1 & \(7^{\circ}43^{\prime}42.58^{\circ}\) S & \(109^{\circ}1^{\prime}14.29^{\circ}\) E & Budi Utomo street riverbanks \\ House 2 & \(7^{\circ}43^{\prime}43.29^{\circ}\) S & \(109^{\circ}1^{\prime}12.63^{\circ}\) E & Budi Utomo street riverbanks \\ Building 1 & \(7^{\circ}43^{\prime}40.88^{\circ}\) S & \(109^{\circ}1^{\prime}7.96^{\circ}\) E & Budi Utomo street \\ Building 2 & \(7^{\circ}43^{\prime}49.18^{\circ}\) S & \(109^{\circ}1^{\prime}16.36^{\circ}\) E & Penyu street \\ Building 3 & \(7^{\circ}43^{\prime}34.51^{\circ}\) S & \(109^{\circ}1^{\prime}19.45^{\circ}\) E & Budi Utomo street \\ Building 4 & \(7^{\circ}43^{\prime}36.84^{\circ}\) S & \(109^{\circ}1^{\prime}19.34^{\circ}\) E & Budi Utomo street \\ Seafront building & \(7^{\circ}43^{\prime}39.45^{\circ}\) S & \(109^{\circ}1^{\prime}27.18^{\circ}\) E & comparison parameter \\ \hline \hline \end{tabular}
\end{table}
Table 2: Position of object point (Premark) GCP.  
Figure 4: The setting of the autopilot flight area developed using DroneDeploy software.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Description** \\ \hline Ground control points (GCP) & Premark, at 10 points \\ Drone type & Dii Phatom 4 and Dii Mavic Pro \\ Camera & Sensor 1/2.3 (CMOS) \\ Adjustable Aperture & f/2.8 and f/2.2 \\ Software track autopilot & DJI GO 4 and DroneDeploy \\ Area to be mapped & 46 Hectares \\ Flight duration & 204:24 min \\ Flight altitude & 100 m above takeoff position \\ Resolution & 3.3 cm/px \\ Photo resolution & 4000 pixels (Width) \(\times\) 3000 pixels (Height) \\ Totals of photos & 4853 \\ Time & 27 June 2021 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Equipment specifications and parameters.  
There were no issues with the region's reconstruction because no structures had high density or complexity. The drones were flown high enough above the buildings (100 m from ground level) to prevent the overlapping value being reduced. Some of the issues experienced while flying drones on the field, such as changes in wind speed in the morning, afternoon, and evening, resulted in reductions in the drone flying speed. Changes in the amount of light, which can be more significant during the day, as well as reflections of light from the sea surface, might impact camera calibration quality. To overcome this problem, before we could fly the drone, we had to wait until the amount of sunlight reflected during the day had lowered.