**3.4 Description of the example area**

The criterion of the efficiency is to get information about the change we want to detect as quickly as possible. On the one hand, this can prevent the occurrence of unwanted change (e.g. surveillance of the security area for crime prevention), and on the other hand, it can reduce the extent of change, such as the amount of resources needed for liquidation (e.g. flood management).

The negative effect caused by the phenomenon is minimal if it is detected immediately. In some cases, this may mean immediate detection (e.g. crime), while in others it is more time-consuming (e.g. forest fire detection). In this latter mentioned case, e.g. the author's experience and other sources [25–27] accept that detection within 15 min of the occurrence of a fire can be called effective. Apart from the extreme fire spread possibilities, the extent of the fire still allows for safe firefighting by using minimal power and tools.

For the purpose of path planning, we can create a large number of routes on the responsible area which should be followed by the staff during the patrol. Optimization requires the shortest route during the patrol with the same rate of observation time per a pixel of the given area. It can be observed that in ideal case pathway cannot cross itself during a cycle. Depending on the scale of the responsible area and the size of the observed pixel at the same time made by the autonomous systems, we can create many path configurations with the equivalent value as shown in **Figure 4**.

When judging the effectiveness of patrolling, the basic question is how fast the autonomous system can do a report on the detection of a problem at any location. Patrolling can be divided into a period of one cycle for a specific area of under "observation" and "non-observation". The "blind area" can also be used for the non-observed area.

In the following, a sample area will be presented. Its parameters can be changed, so it can be adapted for other tasks as well. The area is a regular quadrilateral whose terrain condition does not limit the effectiveness of observation from the side. So it can be considered as a flat surface for the examination. The size of the examined area is 24 km × 24 km, making the whole area of 576 km2 .

According to the assumption, the autonomous system, which makes the patrolling, can run at different speeds on any route because of the nature of the area. It means the detection is done in two dimensions. An additional assumption is that the device installed on board of the autonomous system provides an angle of view that allows the simultaneous viewing of a 3 km × 3 km area at a given time.

Based on the above, we have the following data:


During the assumption the camera on board has an angle of view that allows a simultaneous viewing of a 3 km × 3 km area at a given moment. In this test, we increase the speed of patrolling within reasonable limits, and next we increase the angle of view of the camera. Our aim is to determine how the observed and the blind area changes to an arbitrary point and what further conclusions can be drawn from the trend of change.
