According to State-run Chinese media, the People’s Liberation Army gained the ability to track the U.S. Air Force’s Lockheed Martin F-22 Raptor stealth fighters over the East China Sea. While dismissing the Chinese report can be easy, the claim is not far distant from reality. As a matter of fact, the possibility that China can track the Air Force Raptor is very real. Stealth is not an invisible technology, after all. The cloak of the Stealth just delays the detection and tracking capabilities and signals.
First and foremost, a Raptor that is capable of carrying fuel tanks externally- in which they often do during “ferry missions”- that does not constitute a stealth configuration. Even more, the aircraft is normally equipped with a Luneburg lens mechanism situated on its ventral side during operations of peace time that enhances its location detection on radars.
With that said, contrary to popular belief, combat-configured F-22s are undetectable by any radars. And the same goes for other tactical fighters size stealth aircraft that have empennage surfaces such as tailfins—the F-35, PAK-FA, J-20 or J-31, as it would defy basic physical principles if they were invisible.
Basic laws of physics dictate that in order to defeat high-frequency bands such as the top part of the S bands and C, X, and Ku, the tactical fighter size stealth aircraft must be fully optimized. There is a “step change” in a Low Observable visible signal whenever the wavelength frequency reaches a point that is higher than a predetermined threshold in which case the reaction is a resonant effect. Normally, that resonance happens whenever a component of the aircraft, such as a tail fin, is captivated as less than eight times the size of a specific wavelength frequency. Officially, smaller size stealth aircraft’s that are not the size nor the weights allowances that would make up 2 feet or more of material coatings that are radar absorbent all over are required make trades that indicate which frequency bands they are most optimize to employ.
With that being said, the end result is that a radar that operates at a band of a lower frequency, such as civilian air traffic control radars, are almost positively capable of detecting and tracking a tactical fighter size stealth aircraft. On the other hand, a stealth aircraft of larger size such as the Northrop Grumman B-2 Spirit, which actually lacks in the number of features that trigger a resonance effect, is surprisingly more able to avoid detection from low-frequency radars than those like the F-35 or F-22. But however, it is typical that the low-frequency radars don’t actually deliver what the Pentagon refers to as a “weapons quality” track that is needed in order to direct a missile directed at a target. “Even if you can see an LO [low observable] strike aircraft with ATC radar, you can’t kill it without a fire control system,” an Air Force official stated recently.
Understanding that, Russia, China, and other leading countries have been developing advanced UHF and VHF band early warning radars. They are utilizing the longest wavelengths in order to send signals to the receiving sensors and provide their soldiers with an identifiable marker indicating the location of where an opponent stealth aircraft might be coming from. But the issue with VHF and UHF band radars is that with lengthy wavelengths, you get big radar resolution cells. This means that contacts will not be tracked with the necessary level of fidelity that is needed in order to guide a weapon onto a target. To put it into terms, a U.S. Navy officer once asked, rhetorically, “Does the mission require a cloaking device or is it OK if the threat sees it but can’t do anything about it?”
Normally, guided weapons that have low-frequency radars are limited by two considerations. One consideration is the radar beams width, and the second is the radar pulse width. But nonetheless, both limitations can be overridden using signal processing. Phase array radars, which are specifically active electronically scanned arrays (AESA), worked to provide a solution to the problem of directional resolution since they are able to steer their radar beams using electricity.
Furthermore, AESA radars have the ability to generate beams of multitude while having the capability to shape those beams in terms of with, sweep rate and other significant characteristics. While it is true that some industry experts recommend that the generation of a weapons quality track could be had with the combination of low-frequency phase array radars and high-speed data links.
In collaboration with the US Navy, Lockheed may have developed a solution to a problem. The military branch openly comments on the E-2D’s position as the central node of its NIFC-CA battle network that is particularly designed to defeat enemy threats of air strikes and missiles. The Navy’s director of air warfare, Rear Adm. Mike Manazir, provide a detailed description of the concept at the United States Naval Institute prior to the 2013 Christmas.
Under the NIFC-CA ‘From the Air’ (FTA) construct, the APY-9 radar is to perform as a sensor that signals Raytheon AIM-120 AMRAAM air-to-air missiles for Boeing F/A-18E/F Super Hornets fighters by way of the Link-16 datalink. Even more, the APY-9 is charged with the task of performing as a sensor that guides Raytheon Standard SM-6 missiles that have been launched from the Aegis cruisers and destroyers against targets situated past the ships’ SPY-1 radars’ horizon via the Cooperative Engagement Capability data link under the NIFC-CA ‘From the Sea’ (FTS) construct. The fact is, the Navy has displayed live-fire NIFC-CA missile shots utilizing the E-2D’s radar to guide SM-6 missiles against over-the-horizon shots—which by definition means the APY-9 is developing a weapons quality track.
The end result is that stealth tactical aircraft will be required to operate alongside electronic attack platforms such as the Boeing EA-18G Growler. In addition, there is also the reason why the Pentagon has been storing American ramping up their investment into electronic and cyber warfare. As it was explained by an Air Force official, electronic and stealth attacks has consistently maintained a synergistic relationship as a result of detection being based on the signal-to-noise ratio. Minimal observables reduce the ability to receive the signal, while the increase in electronic attacks increases the static noise. “Any big picture plan, looking forward, to deal with emerging A2/AD threats will address both sides of that equation,” he said.
As technology advances globally, the Air Force is left to rethink their stealthy Raptors for the future of air combat. It is only expected, that as we grow and learn, so do our neighbors and their neighbors. The question is, who will lead the race. The US Air Force or someone else?