IRST gives Super Hornets counter-stealth capability

The US Navy has awarded the Boeing company a US$152 million contract to complete the design, development, integration, and testing of the Infra-Red Search Track (IRST) system for the F/A-18E/F Block III, the latest variant of the Super Hornet, Defense Update reported.

A few days later the company received another US$208 million contract to integrate and produce Lockheed Martin’s Legion Pod IRST for the US Air Force F-15C/D fleet.

The new Block II IRST will replace the Block I system which did not meet the Navy’s requirements. This “see first, strike first” capability empowers pilots with greater reaction time, improving survivability.

Development and testing are expected to conclude in 2021, in time for expected Super Hornet Block III deliveries. The first part of this program was an US$89 million order awarded in June 2017. In October, the sensor’s manufacturer, Lockheed Martin was awarded US$100 to upgrade the IRST21 sensor for the new Block II standard.

The IRST will enable the Navy fighters to target adversaries beyond visual and radar range, and enhance survivability in radar denied environment, operate against existing and emerging air threats.

Better yet … IRST is completely passive and does not highlight the location of the aircraft, unlike when a pilot decides to use the on-board radar, which can give away its position as radio frequency energy bursts out.

IRST can also work in all weather conditions as it uses the infrared rather than the visible part of the electromagnetic spectrum.

While the US services have yet to embrace IRST technology, some of NATO air forces, as well as Russia and China are employing such systems, as well as Singapore and South Korea on their F-15s.

IRST relies on the thermal signature emitted by the target, tracked from a very long distance. While these tracks are affected by clouds and humidity, the high sensitivity of the Long Wave sensors is optimized for operations even under adverse visibility conditions.

The IRST consists of a passive long-wave infrared receiver, a signal processor, inertial measurement unit and environmental control unit packed into a section of a fuel tank attached to the belly of the Super Hornet, the report said.

It will be part of an avionics upgrade that will prepare the Super Hornet to fight modern adversaries. Other elements of that upgrade include the Distributed Targeting Processor — Networked computer, a new, powerful processor that will increase the capability to process multiple tracks, from on board and remote sources, in real time.

Remote tracks will be delivered over a new, high speed data link known as the Tactical Targeting Network Technology, that enable several Super Hornets flying a loose formation to share many tracks picked by their IRSTs, to passively “fix,” geolocate and determine the range and heading of each target, just like a radar — something a single IRST cannot do.

According to The National Interest, once either China or Russia manages to put together long-wave infrared search and track, high-speed data links, and the computers and algorithms for multi-ship sensor fusion, the ability of US fifth-generation fighters to operate independently will diminish.

That’s bad news for the Pentagon, of course. It suggests, it is only a matter of time before both China and Russia will be able to shoot down F-22s and F-35s.

The Russians — The National Interest reported — have had infrared search and track sensors onboard their fighter aircraft for decades. Even the earliest versions of the Mikoyan MiG-29 Fulcrum and the Sukhoi Su-27 Flanker have had an IRST system installed.

The Russians have continued to field modern fighters such as the Sukhoi Su-30SM and Su-35S with newer and more modern IRST technology even if the detection ranges are fairly unimpressive. Even the forthcoming Su-57 PAK-FA incorporates the 101KS-V infrared search and track system.

Both Russian and Chinese defense industries have experience building IRST sensors and should be able to develop a long wave infrared search and track pod without too much difficulty.

By the same token, both the Russians and the Chinese have access to airborne data-networking capability. The Russian Mikoyan MiG-31 Foxhound is equipped with RK-RLDN and APD-518, the later of which can coordinate a flight of four jets.

Newer Russian fighters such as the Su-30SM, Su-35S and the Su-57 also incorporate datalinks — as do their Chinese counterparts. However, the speed and throughput of these datalinks remain in question, but it is all but a certainty that both Moscow and Beijing have the wherewithal to develop high-speed high band airborne datalinks.

Once the Russians and Chinese have the ability to link two or more longwave IRST-equipped jets via a high speed link, they would have most of the ingredients needed to build a counter-stealth capability.

That leaves the question of Russia and China being able to develop advanced sensor fusion algorithms, which is a challenging undertaking even for American defense contractors.

It will take time, but it is likely that both nations have the ability to develop such software and the computing hardware to make it work. Beijing, which has more access to external sources of computing technology, is more likely to be able to develop such an avionics package first in the the relative near term.

However, Russia will also probably be able to develop a similar capability given time — and possibly access to foreign processors from China perhaps if sanctions are not lifted.

Indeed, the U.S. Air Force anticipated this development—the service noted that its F-22 Raptor would be increasingly challenged by the 2030s by new enemy capabilities.