# Situational Awareness and Problems of Its Formation in the Tasks of UAV Behavior Control
## 3 The Situation and Situational Awareness in Behavior Control Problem for UAV
Scene \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)\) is the result of the representation of the situation \(\Lambda(\mathcal{R}^{\mathcal{W}},t)\) in some perceiving media. Since the considered UAV is one of the elements of the fragment \(\mathcal{R}^{\mathcal{W}}\) of objective reality, and \(\Lambda=\Lambda_{int}\cup\Lambda_{ext}\), the following relation takes place:  
\[\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)=\mathcal{S}^{\mathcal{R} \mathcal{W}}(\Lambda_{int})\cup\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda_ {ext}); \tag{17}\]  
that is, the scene \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)\) is a union of two sets \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)_{int}\) and \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)_{ext}\) elements, corresponding to the internal and external components of the situation, respectively. Representation of objective reality in some perceptual environment, i.e., the transition from situation to internal \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)_{int}\) and external \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)_{ext}\) components of the scene \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)\), is done by using appropriate technical equipment. Which devices should be used to obtain \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)_{int}\) and \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)_{ext}\), and in what form they should reflect objective reality, depends on the specific tasks to be performed. The variety of tools that can be used to form \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)_{int}\) and \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)_{ext}\) is rather large [90; 91; 92]. A not complete list of such tools for \(\mathcal{S}^{\mathcal{R}\mathcal{W}}(\Lambda)_{ext}\) includes:  
* tools for working with data in the visual and infrared range (video cameras, OELS, IR cameras);acoustic data handling equipment (helicopter lowered hydroacoustic station (HSS) + hydroacoustic buoys (HBS));
* tools to work with radar data (radar stations of various kinds);
* external data sources concerning the UAV (GPS/GLONASS, radio navigation tools, motion capture tools). Similarly, the list of tools for generating \(\mathcal{S}^{\mathcal{RV}}(\Lambda)_{int}\) can include facilities such as:
* tools for sensing UAV state variables (gyroscopes, accelerometers, ROVs, angle-of-attack and angle-of-slip sensors, etc. );
* devices and sensors that characterize the state of the atmosphere (air density, turbulence, wind, etc. ), for example, meteoradar;
* inertial navigation instruments. * sensors providing control of the <<health state>> of the UAV systems and design. None of the sources of information about environmental objects due to various limitations does not allow getting a complete information picture. For example, one of the most important for UAVs, the visual channel, cannot cope with such disturbances as cloud cover, fog, and nighttime. These phenomena are not a problem for the radar channel, but it does not allow one to perceive the observed object with great detail, which is quite usual for the visual channel. Hence, to obtain situational awareness, acceptable for control purposes, it is necessary to get data from several sources and solve the problem of merging information from them. Full formation of components \(\mathcal{S}^{\mathcal{RV}}(\Lambda)_{int}\) and \(\mathcal{S}^{\mathcal{RV}}(\Lambda)_{ext}\) of the scene \(\mathcal{S}^{\mathcal{RV}}(\Lambda)\) requires numerous and heterogeneous perceptual devices. This fact causes the problem of sensor fusion, that is, the problem of obtaining a consolidated information picture based on data from a set of tools perceiving the components of the situation. Finally, the last, third definition among those formulated above introduces the concept of situational awareness \(\Lambda^{\mathcal{A}}(\mathcal{S}^{\mathcal{RV}},\Gamma)\) as information extracted from the scene \(\mathcal{S}^{\mathcal{RV}}(\Lambda)\), according to the control goal set \(\Gamma\). This information serves as input to the UAV behavior control system.