# Trustworthiness of Situational Awareness: Significance and Quantification
## 1 Introduction  
Situational awareness (SA) is the perception of entities in an environment, the comprehension and interpretation of their meaning, and the projection or prediction of their status in the near future. From an air force perspective, SA means the capability of understanding the current and future disposition or status of red and blue aircraft and surface threats within a volume of space [1]. SA is of a tremendous significance for military and air forces, and is considered as the decisive factor in military and air combat engagements [2, 3]. The United States Air Force (USAF) war theorist Colonel [PERSON] [4] considered SA as analogous to the \"observe\" and \"orient\" stages of the observe-orient-decide-act (OODA) loop. SA is also an integral component of military command and control (C2). The C2 is comprised of SA, planning, tasking, and control. The C2 system design is intended to present the situation to the commander in a way that promotes the accurate and comprehensive understanding of the situation so that the best action can be taken. Figure 1 provides an overview of an SA system from an air force perspective. Figure 1 shows the sources that are typically employed in a military and/or air force to obtain SA. These sources include short-range and long-range intelligence, surveillance, and reconnaissance (ISR) UAVs, fighter and reconnaissance aircraft, satellites, radars, heads-up displays (HUDs), helmet-mounted displays (HMDs), and different types of sensors, such as gunshot detectors and locators, microphones, audio recorders, smoke/fire detectors, and motion sensors. The sources of information for providing SA can be categorized ashuman intelligence (HUMINT), measurement and signature intelligence (MASINT), imagery intelligence (IMINT), open source intelligence (OSINT), signals intelligence (SIGINT), and geospatial intelligence (GEOINT). HUMINT is a type of intelligence derived from information acquired and provided by human sources. MASINT refers to the intelligence obtained by acquiring and measuring the intrinsic characteristics and components of an object or activity via sensing instruments that enable the object or activity to be detected, recognized, or characterized every time it is encountered. MASINT includes radar intelligence, acoustic intelligence, nuclear intelligence, and chemical and biological intelligence. In IMINT, imagery is analyzed to infer information of intelligence value. For defense intelligence purposes, imagery that is typically utilized is acquired by satellite or aerial photography through ISR UAVs or aircraft. OSINT refers to the type of intelligence that is obtained from capturing and analyzing publicly available information, such as news media, public records, social media platforms, and websites, etc. SIGINT is a type of intelligence derived from the interception and collection of information from various electronic signals and systems, such as communications systems (including decoding encrypted messages), radars, and weapons systems, and is often used to obtain insight into the modus operandi of an adversary or target. GEOINT refers to the type of intelligence that exploits and analyzes imagery and geospatial information to assess and visually depict physical features and geographically referenced activities on Earth. GEOINT comprises imagery, IMINT, and geospatial information. Information gathered from these different intelligence sources is fused with the help of data fusion systems (e.g., radar data fusion, aircraft data fusion, UAV data fusion), and is then passed to a common operating picture (COP) builder computer, which engenders a COP or user-defined operating picture (UDOP), which is an evolution of the COP. The SA devices are integral for obtaining perception and comprehension of an environment; however, SA devices and an SA system are vulnerable to adversarial attacks that can jeopardize the security and trust of SA systems.