The Limits of Radar on the Battlefield
For decades, radar has been the bedrock for tracking and monitoring aircraft for both military and civilian applications. While useful for the FAA to monitor the friendly skies, the technology presents significant limitations for warfighters on the battlefield. Since radar actively emit radio waves, they can alert the enemy, putting lives and critical assets at risk.
"Radar systems are like shining a flashlight in a dark room," explains George Reaves, Director of Engineering, L3Harris. "You can see everything. But now everyone can see you, too."
The Rise of Passive Sensing Technology
This inherent vulnerability has spurred the development of electro-optical and infrared (EO/IR) technologies, which offer alternative ways to see the same picture. Unlike traditional radar, EO/IR systems do not emit signals, making them practically invisible to the adversary. This type of passive remote sensing is essential for survival in the modern era of electronic warfare.
A First in Infrared Tracking
The Infrared Search and Track (IRST) system by L3Harris detects and tracks targets anonymously by combining sensors that collect radiation, light and heat signatures, then uses a powerful processing system to convert that data into crisp, real-time imagery. This technology gives warfighters detailed situational awareness without compromising their position.
“With IRST, now you can see clearly and operate freely in the dark,” Reaves said. “Breakthroughs in passive remote sensing like IRST serve as a great example of how L3Harris keeps our customers safe and undetected in combat operations.”
Advanced Sensor Technology in Action
L3Harris has completed a successful flight test of IRST’s capabilities, using advanced Focal Plane Array (FPA) technology and real-time processing algorithms, an exponential leap forward in passive EO/IR system development.
“Think of it as having multiple pairs of eyes, each finely tuned to different wavelengths,” Reaves explains.
How the System Works
IRST combines several passive sensors to capture targeting data, including long-wave infrared sensors that detect heat signatures and low-cost micro-bolometers widely used in night-vision equipment. Adding mid-wave infrared sensors further enhances the system’s ability to operate day or night and in challenging environmental conditions.
Flight Test Success
The target aircraft flying alongside the host aircraft prior to system test.
During the test flight, L3Harris successfully demonstrated the capabilities of FPA sensors and computing power in a realistic operational setting. Flight engineers mounted an AgilePod on a host aircraft which housed the real-time image processor.
In addition to designating the target, the system detected, identified and tracked two commercial aircraft within the test field of view. The results demonstrate the system’s ability to properly process a range of signal inputs in a complex environment while avoiding false alarms and, more critically, friendly fire incidents.
The target aircraft (middle square) and two additional commercial aircraft being tracked by L3Harris’ IRST system, demonstrating precise, passive detection in flight.
A Milestone in Electronic Warfare
As the aircraft completed its test flight, the IRST team recognized they had reached a milestone. The silent guardians of the sky had marked a new era in electronic warfare and remote sensing. This advancement in passive EO/IR sensing was more than a technical achievement for L3Harris, it carried the promise of a safer, more secure future for U.S. and allied forces.
“We’re not just building targeting systems,” Reaves said. “We’re building the future of defense, one silent step at a time.”
Following its successful initial flights, the IRST system will undergo additional flight testing. These tests are a key part of the system’s ongoing technical maturation, allowing engineers to refine algorithms, validate performance across operational scenarios and ensure the system continues to meet warfighter needs.
