Generating an Air Situational Picture (ASP) with Advanced Passive Sensor Solutions

The ability to quickly detect, identify and classify aerial vehicles, and to generate an Air Situational Picture (ASP) that distinguishes between actual threats and innocent targets, is essential for the effective performance of the air defense mission. However, this task has become increasingly difficult for several reasons. The continuing growth in worldwide civil aviation traffic has resulted in denser national aerospace, making the timely and accurate identification and classification of penetrating targets more demanding. Another issue is the proliferation of small aerial platforms with minimized Radar Cross-Section (RCS). The increasing use of small, slow, low-flying platforms, and the spread of stealth technologies, challenge the ability of radar systems to detect, track and classify these threats.

Finally, survivability becomes an issue in the event of a conflict, with active air-defense sensors detected by adversary ISR (Intelligence Surveillance and Reconnaissance) systems and targeted by precision-guided munitions.

The use of passive sensors on their own or in conjunction with active radar systems to create a unified multi-discipline ASP provides important advantages:

• Better awareness – Quicker and more accurate classification and identification of targets to support the critical air situation picture. Passive sensors enable long-range detection, continuous tracking, and the ability to discriminate between targets based on their SIGINT signature.

• Better efficiency – Improved efficiency of defense weapons systems by reducing classification and identification times and providing more interception opportunities.

• Better survivability – Passive systems are compact, do not emit RF, and facilitate careful use of radar transmissions.

The passive ASP is generated by the following sensors, which may be integrated into the air defense system:

• ELINT – The Electronic Signal Intelligence (ELINT) system enables the detection of targets at longer ranges and sustains tracking continuity by exploiting target side lobes. The ELINT sensor’s high sensitivity and ultra-wide bandwidth scanning significantly improve the detection of targets equipped with advanced low probability-of-intercept radar systems. This innovative scanning capability enables the ELINT system to perform simultaneous scanning of an extensive bandwidth, successfully tracking targets that employ sophisticated radars equipped with advanced frequency agility and frequency selection systems.

• COMINT – Detecting threats based on intercepting communications; this is the only sensor that can provide complementary information regarding the target’s intent.

• PCL – The Passive Coherent Location (PCL) multi-static radar system detects and tracks emitting and non-emitting targets passively. It uses the target reflection from multiple non-cooperative transmissions, such as FM or digital audio broadcasts, and can detect and track targets without actively transmitting.

The passive SIGINT sensors complement the ASP provided by radar and enhance situational awareness with timely target detection and classification. The synergistic integration of data from passive and active sensors presents considerable challenges and requires advanced, sophisticated data extraction and transformation techniques. ELTA’s passive sensor integration system, Acapella, creates a unified and centrally managed air situational awareness picture.

The ability of passive sensors to classify and identify aerial targets with unchallenged reliability directly impacts air defense performance. The quick and unambiguous identification of threats facilitates more rapid activation of air defense capabilities, creating more opportunities for target interception by ground-based air defense systems and air superiority aircraft. Furthermore, passive sensors support advanced Concept-of- Operations (CONOPS) with more conservative radar transmission protocols for enhanced survivability and improved efficacy.

ELTA’s Passive ASP solution leverages advanced SIGINT capabilities to provide a significant force multiplier for the air surveillance and defense mission.