Defining the mission area
This is the first and obvious task to perform. The area over which images are intended to be taken should be known and well defined. It may be necessary to have this area in a Geographic Information System (GIS) as a polygon layer. This will later help you in determining the number of flight lines necessary to cover your mission area.
It is possible to have an area of interest that is too big for the UAV to image in a single flight. UAVs operate with batteries, so the lifespan of the battery determines how long it can stay in the sky and for that matter, the area it can cover before it runs out of battery. In such cases, one can cover the whole study area by making multiple flights using two or three UAVs in an overlapping manner. Alternatively, the study area can be divided into different flight areas (or mission areas) and imaged. For example, the STARS study area in Mali had to be divided into seven mission areas due to its size vis-à-vis the duration of the battery of the UAV used (figure 5.3). This ensured that each mission area could be completely imaged during one flight. In such cases, mission planning has to be done for each mission area.
Figure 5.3. The seven mission areas in the STARS site in Mali (Source: STARS ISABELA team)