5.2.1. Defining the mission area

This is the first task to perform. The area over which images are required must be known and be well-defined. It may be necessary, or at least useful, to have the area as a polygon layer in a GIS. This will later help in determining the number of flight lines needed to cover the mission area.

It may be the case that the area of interest is too big for the platform to cover in a single flight. UAVs operate with batteries, so their lifespan determines maximum flight duration and thus, the area it can cover. Multiple flights using two or three UAVs in an overlapping manner may then be needed. Alternatively, the study area can be divided into different flight areas (flight clusters). For example, our study area in Mali had to be divided into seven clusters due to size vis-à-vis the duration of batteries on the UAV used (Figure 5.3).

Figure 5.3. The seven mission areas in the Mali site. The area measures 6370 (west-east) by 4860 m (north-south). (Source: ICRISAT)