How to detect stealth aircraft

Radar, with its ability to send out radio waves and receive their echoes, serves as the vigilant eye in the sky. However, detecting stealth aircraft presents a unique challenge due to their advanced technologies designed to evade traditional radar systems. Let’s explore the intricate dance between stealth and radar, shedding light on both the methods employed to detect these elusive aircraft and the countermeasures taken to remain undetected.

Stealth aircraft detection radar
AN-TPS-117 L-Band Long Range Radar

Frequency Agility

Radar systems operate within specific frequency bands, such as X-band and S-band. Stealth aircraft designers take advantage of this by creating systems that can adapt to various radar frequencies. This frequency agility allows stealth aircraft to minimize their radar cross-section across a broader spectrum, making it difficult for traditional radar systems to lock onto them.

Lockheed Martin AN/TPS-59(V)3 Long-Range Radar – Known for its ability to operate in different frequency bands, this radar provides a versatile solution against stealth technologies.

U.S. Marines with Marine Air Control Squadron (MACS) 1, Marine Corps Air Station (MCAS) Yuma, conduct a routine check up on an AN/TPS-59 Radar on Cannon Air Defense Complex, MCAS Yuma April 5, 2020. The AN/TPS-59 Radar is a long-range transportable radar system used to detect and track threats to MAGTF operations. (U.S. Marine Corps Photo by Lance Cpl. John Hall)

Dual-Band Radars

Dual-band radar systems operate in two different frequency bands simultaneously. By combining, for example, X-band and L-band, these radars can enhance detection capabilities. While stealth aircraft may have optimized features for one frequency range, the dual-band approach ensures that the radar can detect them effectively across multiple bands, reducing the likelihood of evasion.

Raytheon AN/SPY-6(V) Air and Missile Defense Radar (AMDR) – This radar employs multiple bands, including S-band and X-band, offering enhanced capabilities for detecting stealth threats.

Photo courtesy of Raytheon

Longer Wavelength Radar

Longer wavelength radar, often associated with lower frequency bands such as L-band or UHF, poses a challenge for stealth aircraft designed to be more effective against higher-frequency radar systems. The longer wavelengths can interact differently with the aircraft’s surface, potentially revealing its presence. Consequently, radar systems with longer wavelengths become valuable tools for detecting stealth aircraft.

Thales Ground Master 400 – Operating in the UHF band, this radar is designed to detect low observable threats, including stealth aircraft.

Multifunction Radar Systems

Modern radar systems are evolving to become multifunctional, employing a combination of different frequency bands and advanced signal processing techniques. This adaptability enables radar systems to detect and track stealth aircraft by utilizing a mix of frequencies, making it challenging for the aircraft to remain invisible across all bands simultaneously.

Northrop Grumman AN/APG-83 Scalable Agile Beam Radar (SABR) – Renowned for its multifunctionality, SABR operates in various frequency bands, providing superior situational awareness and detection capabilities.

Northrop Grumman AN APG-83. Photo courtesy of Northrop Grumman

Non-Radar Sensors

Beyond traditional radar, non-radar sensors like infrared and acoustic systems come into play. Stealth aircraft may have reduced visibility on radar, but they still emit heat and noise. Infrared sensors can detect the thermal signatures of aircraft, while acoustic sensors pick up on the subtle sounds they produce, providing an alternative means of detection.

BAE Systems Digital Acoustic Sensor – This advanced acoustic sensor system is designed to detect and classify airborne threats, including stealth aircraft, by analyzing their unique acoustic signatures.

Electronic Warfare (EW)

Electronic warfare techniques involve disrupting or jamming the radar signals. While stealth aircraft are designed to counteract radar waves, electronic warfare systems attempt to overwhelm and confuse these defenses. By saturating the airspace with electronic noise, EW can compromise the effectiveness of stealth technology.

Harris AN/ALQ-214 Integrated Defensive Electronic Countermeasures (IDECM) – This electronic warfare suite is designed to protect aircraft from radar-guided threats, countering attempts to detect stealth aircraft.

Electronic Warfare (EW)

Electronic warfare techniques involve disrupting or jamming the radar signals. While stealth aircraft are designed to counteract radar waves, electronic warfare systems attempt to overwhelm and confuse these defenses. By saturating the airspace with electronic noise, EW can compromise the effectiveness of stealth technology.

Harris AN/ALQ-214 Integrated Defensive Electronic Countermeasures (IDECM) – This electronic warfare suite is designed to protect aircraft from radar-guided threats, countering attempts to detect stealth aircraft.

Bistatic and Multistatic Radar

Traditional radar systems operate in a monostatic manner, where the same system transmits and receives signals. Bistatic and multistatic radar setups involve separate transmit and receive locations. This configuration can provide additional angles and perspectives, increasing the chances of detecting stealth aircraft that might be optimized to minimize detection from a specific direction.

European Space Agency’s TRUTHS (Traceable Radiometry Underpinning Terrestrial- and Helio- Studies) – Although not primarily for military use, the concept of bistatic/multistatic sensing could influence future radar systems. TRUTHS explores the potential of separating transmitters and receivers in space-based Earth observation, contributing to innovative radar technologies.

Meteorological Conditions

Stealth aircraft may find their invisibility compromised in adverse weather conditions. Rain, snow, and atmospheric phenomena can affect radar waves differently, potentially revealing the presence of stealth aircraft under certain circumstances.

MIT Lincoln Laboratory’s Advanced Weather Radar – Designed for atmospheric research, this radar system provides high-resolution data on precipitation and atmospheric conditions, inadvertently influencing how stealth aircraft may be impacted by weather-related radar effects.

In the cat-and-mouse game between stealth technology and radar detection, ongoing advancements on both sides continually shape the future of aerial warfare. While stealth aircraft strive to maintain their elusive nature, radar systems and associated technologies persistently evolve to uncover the hidden secrets of the skies.

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