Should Gen 4.5+ capabilities such as sensor fusion, firing through IRST and ESM, and low-observability be modeled?
- Yes
- No
According to certain translators, BVVD was asked on the recent live-stream, “With 5th gen, you said it would be in second half of 2026?” and BVVD replied “Well the second half of 2026 didn’t end yet”.
While some of the playerbase and Gaijin seem to be eager to add 5th gen jets this year, there is a very big and strong concern surrounding the addition of 5th gen jets with a few months left before year’s end.
Throughout the history of Warthunder, the jump to the next generation of aircraft were not made until the current generation of aircraft and their capabilities were substantially modeled, this provided an easier and smoother transition to the capabilities of the next generation. For instance, late 3rd generation aircraft had received pulse-doppler and more complex radar modeling that would also be seen in early 4th generation aircraft. The same cannot be said here for late 4th generation aircraft compared with 5th generation aircraft.
Most if not all tech trees in-game have a way to obtain a 5th generation aircraft whether from domestic service or through subtree additions, but for a majority of the tech trees this looks to be through the F-35 aircraft. The F-35 aircraft is a very capable modern jet but for one reason or another, to many players this aircraft comes second to a domestic design Gen 4.5+ aircraft such as the Rafale or Eurofighter or the Gripen E. The F-35 Lightning II jet is a formidable aircraft but is suboptimal from the view of many players who do not wish to play a vehicle that will likely be spread freely across many trees, and lack the distinct diversity and therefore it is imperative that Gen 4.5+ capabilities are modeled so that players can continue to enjoy their preferred vehicles at the top battle-rating against 5th gen aircraft.
Part 1: Sensor Fusion
The literature available on Gen 4.5+ aircraft show that these aircraft have a great amount of capabilities, these are not limited to solely Gen 4.5+ aircraft, and more often some of these capabilities are available on Gen 5, but they are heavily marketed alongside Gen 4.5+ aircraft.
One of these capabilities is sensor fusion.
Sensor fusion is the concept that aircraft are able to operate different sensors such as radar, IRST, and ESM and combine the different sources of the sensors in order to produce a more accurate picture as well as provide a higher quality of targeting data.
For the sake of this topic, we are only talking about sources of sensor data from the current available sensors in-game which consists of ESM, radar, and IRST. Currently in-game you can only utilize one of these sensors at a time when you should be able to utilize all 3 at the same time. Sensor fusion also means that the limitation or disadvantages in each of these sensors should always be evaluated by the aircraft and the more accurate sensors should be preferred.
For instance, radar has more inaccurate bearing resolution than IRST, so the information on a target from IRST + Radar combined should produce more accurate bearing resolution on targets than an aircraft with only radar.
Currently systems such as ESA and IRST lack some of the more in-depth modeling that would provide greater detection and this ties into part 1 largely because the efficacy of sensor fusion depends a large part on the accurate modeling of the separate systems that feeds data into sensor fusion.
IRST with modern vehicles often function as optics that can transmit images of targets or particular areas. This would allow for aircraft of Gen 4.5+ to monitor potential targets even at distances beyond the radar’s ability to pick up stealth targets.
IRST systems at top-tier lack key features track-while-scan, as well as being able to search the whole field of regard, these issues have been reported. ESA radars also lack the ability to conduct a second separate search independent of the selected search zone as well as the ability to keep track of targets when switching through modes. These capabilities are critical to Gen 4.5+ aircraft in being able to combat against 5th gen jets.
Spoiler
Eurofighter - IRST lacks option to search entire field of regard // Gaijin.net // Issues
Rafale’s IRST is missing a 180x40 scan option // Gaijin.net // Issues
JAS39E’s IRST missing track-while-scan mode // Gaijin.net // Issues
Rafale’s FSO-IRST is missing track-while-scan // Gaijin.net // Issues
Eurofighter - PIRATE missing track while scan mode // Gaijin.net // Issues
Aircraft such as the Eurofighter and Rafale are claimed to have low-observability characteristics or LO. This should not be confused with very low-observability characteristics or VLO that is associated with 5th gen aircraft. Both aircraft have an accepted report for their signature reduction characteristics and both remain unimplemented as of currently. While no gen 4.5+ aircraft have an internal bay and they also produce higher returns with a weapons loadout, reduced RCS would still provide some advantages against 5th gen in that chaff is more effective when defeating radar missiles.
5th gen aircraft are hard to target with radar by nature of their inherent low-observability characteristics. Measures against aircraft through the use of other spectrums such as IRST and ESM helps provide avenues to neutralize 5th gen aircraft and lowers the advantages associated with 5th gen stealth aircraft.
Being able to utilize different sensors at the same time means that radar, IRST, and ESM are all able to keep track of a threatening stealth aircraft even as it moves around the battlefield. A stealth aircraft moving from being front aspect to side-aspect in the notch means that it could result in a lower likelihood of being tracked in radar to a higher likelihood in being tracked in IRST due to the engine showing.
Currently firing through the IRST still is not modeled yet despite developers being aware that this is a possibility.
A threatening 5th gen stealth aircraft emitting radar emissions realistically should be able to be fired upon with ESM even at ranges where the stealth aircraft itself is not yet detected on radar. This mechanic is not possible in-game yet either.
